24 Sep 2010

Trykit 2WD first impressions


The working parts of the Trykit 2WD, double free-wheel drive "freehub".

The entire assembly floats on the inner ends of the two rear axles. Supported by the push fit, oversized, sealed, journal ball bearings. Being so well sealed the bearings offer excellent protection for the internal ratchets, pawls and their carriers. The Shimano cassette fit, 2WD freehub body itself is machined from high quality steel, hardened and plated. The central disk spacer is to aid pushing out the pawl carriers for examination. The pawl carriers have hexagonal bores to take the drive from the mounted cassette, independently, to both rear axles. The Trykit 2WD freehub offers two wheel drive in a compact, robust and lightweight package. The Trykit freehub is easily dismantled without tools. The pawl and their springs are always safely retained in their carriers. So nothing can "fly away" during occasional dismantling for inspection and possible re-lubrication with a light grease.


I will just scribble a few notes before bedtime while the first 2WD riding experience is fresh in my mind:

It was nearing 7pm when I had finished assembly of the Trykit 2WD system of twin free-wheels in a specially made "freehub" style body. I tightened and checked the wheel nuts and pointed the trike down the gravel drive. Just as I had done several hundred times before. I had not refitted my large cloth shopping bag so the trike felt quite a bit lighter and more "agile" than usual. I immediately noticed a front wheel wobble and so did my wife who was seeing me off.  The wobble was odd but inexplicable. I had quickly checked the tyre pressures and head bearings. No obvious problems there. (In retrospect I think the wobble was the trike trying to overcome my reluctance to let it have its head.  I was fighting my ingrained instincts to resist the constant rightwards turning tendency of 1WD.  Causing the trike to feel as if it was weaving)

I took it easy until I reached the road. The trike felt very strange. As if I was learning how to ride one all over again. It seemed to be weaving slightly when I pedalled hard. A bit worrying at first but nothing seemed about to fall off. Once on the road I gradually built up speed until I was doing my usual 20mph. I let go of the handlebars while still pedalling hard up a slight incline and found the trike kept a dead straight course! Normally it would have headed straight for the verge in a hurry. 

I rode on to the nearest real hill, pedalling hard and still feeling a slight weaving effect. There I found that I could climb without holding the handlebars. This was novel indeed! Normally the front wheel would almost lift off the road and jerk viciously to the right on every pedal stroke. I liked this new neutrality a lot. I went in search of a steeper hill to check my findings. The trike still felt fast and agile but seemed to be steering itself at times. Particularly if I deliberately pedalled hard enough to bend the entire trike into a weaving motion at lower pedal revs. The feeling was as if the head bearings were stiff. Though they are actually far too loose and really need replacing.
Cornering had taken on an interesting new feel depending whether I pedalled hard or just tried to maintain speed. Some times it almost seemed to under-steer. At others it was completely neutral. I rode loops up and down on the steepest local hill (fortunately a very quiet lane) to test out my feelings about this 2WD.

My immediate conclusion is that I would have had far less trouble learning to ride a trike with 2WD. It no longer had the nasty 1WD vices which had made me over-react in the early days and later. The feeling of danger as the trike headed for the verge with a mind of its own was now completely absent. I could now maintain a smooth line on heavy camber no matter how hard I pedalled.  The slight under-steer was merely a lack of turning motion from the former 1WD. As was the slight weaving. The trike wasn't misbehaving any more but it felt as it was doing the complete opposite. I was actually sensing the trike correcting itself. Instead of my having to make constant subconscious corrections for its 1WD faults. (i.e.Its unwanted clockwise turning tendency)

I had read that a disadvantage of 2WD was the inner wheel drive making it harder to pull away or turn sharply at low speed. I found no such problems. I turned tight circles on the steep hill without any untoward resistance to my pedalling. Though admittedly I was already in a low gear.

The absence of sideways pull was delightful. I had theorised endlessly for many months, before ordering the Trykit 2WD. How it would cope with European camber? How would it know which wheel to drive to lift the trike out of the right side gutter? The strange answer is that it simply does know what to do without trying. 

I could only manage about half an hour, and five miles of messing about on the lanes, before I had to return home to tidy up. My impressions so far are all entirely positive! I couldn't resist trying to sprint out of the saddle on our very loose, gravel drive just for fun. Normally I can get the drive wheel to spin effortlessly even while sitting down. It always took quite a distance to get any real speed up. With 2WD I accelerated hard and shot down the drive without so much as the slightest slip of my smooth and skinny 700 x 23mm tyres. Absolutely amazing!

I cannot imagine anybody being able to compete on grass or gravel with 1WD against machines fitted with Trykit 2WD mechanisms. It would be hardly worth turning up for a grass track race with 1WD. Not unless the grass was bone dry, there were no straights and the course ridden clockwise. This would put the drive wheel on the outside where it would gain most grip from any tipping tendency on the curves.

BTW: There is zero sensation through the pedals of the drive shifting from one axle to the other. I had worried about this too but there is absolutely nothing to report. Naturally I shall share my experiences further when I have had a proper ride tomorrow. I am looking forward to it even more than usual. The slightly wider track seems to have taken away some of the lateral vibration on rough roads. It feels much more steady. A bit like my even wider and more sedate Longstaff conversion but much lighter and more lively. It's a shame I have to put the big shopping bag back on tomorrow.


24th September 2010. My first proper ride with the Trykit 2WD fitted.  The big bag was lashed back onto the seat stays. The immediate impression was how fast, relaxed and effortless the trike had become. Instead of crabbing constantly to the right all my energy was now going into forward motion. The effect was very noticeable on undulating roads. The friction of the front tyre pressing sideways against the road was now completely absent. I was blasting along up hill and down dale at speeds I could only dream about before today. I was climbing hills on the middle chainring which needed the small one only yesterday. 

The most noticeable effect on the flat is when cornering to the right on really steep camber. I used to avoid the inside of these corners and ride as far out as I dared, depending on following traffic. Now the 2WD could be used to physically lift the trike up the camber simply by pedalling a little harder. Pedal too hard and it felt (almost) as if I could end up in the middle of the road! I really don't think this was an unwanted vice with the 2WD system. More like a lack of 2WD experience on my part. Compensating for the ingrained turning effect of OWD would take some time to unlearn.

After ~10,000 miles of riding one wheel drive trikes over the last 18+ months I have yet to reprogram myself to the completely different sensations with 2WD. I have been subconsciously compensating for so long, that not having to do so, feels like the 2WD is pushing me the opposite way. In fact the two wheel drive is completely neutral. It is my own senses which are still wrong from becoming so accustomed to the bad habits of OWD.

Climbing steep hills was a revelation!  I deliberately went looking for hills to test out the 2WD system. No more snatching to the right! The trike just keeps its nose pointing in the right direction. I could even loose my grip on the handlebars and stay on the straight and narrow! This is truly stunning performance after struggling for a year with the OWD vices on the Higgins. The 2WD actually seems to flatten the hills out. They are no longer the test of patience and gritting my teeth which they once were.

There were some odd moments when I was pulling away when it felt as if the trike wanted to go its own way. (though only slightly) This depended on the starting angle of the handlebars. Again this was because I no longer needed to turn the bars so far to overcome the strong 1WD turning tendency to the right. Low pedal revs and low speed seems to find an occasional feeling of weaving. Perhaps this too is my automatically compensating for a now-missing 1WD vice? My normal cadence of 90+rpm eliminates any tendency to weave.

Those of you living in a country where traffic drives on the right would do well to consider the Trykit 2WD system. Highly recommended based on the 30 miles so far.


I managed another 17 miles this afternoon while concentrating hard on what I sensed about the 2WD system. Again the ride was more relaxed, secure, quieter and still felt much quicker than usual. It really is difficult to separate the 2WD effects from my own "automatic pilot" OWD reactions. Occasionally as I crested the brow of a low hill while pedalling hard the trike felt as if it wanted to go straight on. I'm almost sure this was due to my own senses being fooled by the lack of the usual turning tendency to the right.

Trykit 2WD with 8 speed Shimano cassette. I made the brass spacer ring in the lathe.

Old habits die hard and 40-odd miles is not enough to undo thousands of miles of ingrained expectations. I have become so accustomed to the OWD that even a neutral  force will feel as if it is pushing the other way. Just as a trike feels as if it is pushing you about when you first change over from a bike.

I have been trying to sprint out of the saddle far more than usual and find the trike has quite a strong "straight ahead" tendency. Easily overcome with a slight turn of the handlebars but slightly unexpected for the habitual OWD rider. What is surprising is that the tyres are much quieter when not slipping about on every bit of sand and gravel at junctions. The lack of wheel spin feels much more secure in traffic.

I have discovered one slight, unforeseen problem so far. If I stop in a high gear I can no longer just lift the drive wheel to drop onto a lower gear with a flick of the pedals. So pulling away takes a bit longer while I find a lower gear. I shall just have to learn to drop onto a smaller chainwheel as I come to a halt each time. No real hardship with a little practice. If the trike wasn't so heavily loaded I could lift the whole back end to drop down a few gears while at a standstill.

The extra half inch of track width is well worth having on rough roads. The trike no longer behaves quite like the bucking bronco which I have become so used to on the badly maintained lanes and roads.

In summary, I would suggest that riding a OWD (one wheel drive) trike is handicapping both yourself as a rider and the capabilities of the machine itself. The advantages of 2WD make the choice automatic for trike riders living outside the UK. Even within the UK, where you have the benefit of OWD to lift the trike out of the left gutter, then a Trykit 2WD still makes a lot of sense.

On the Higgins you get new, stronger axles without the stress raising machining at the most critically loaded points of both axles. You get considerable freedom from wheel spin on wet roads, steep inclines, fords, grass, sand, snow, ice and gravel. Climbing steep hills will become much easier. Any tendency for the machine to try and turn right is completely eliminated. No doubt you'd get much lighter tire wear into the bargain.  Once 2WD has been tried there is no going back to OWD. To do so would be unthinkable.


Another update:  I have discovered that I can ignore camber with 2WD. My habit of riding on the crown of the road on heavily cambered lanes is now unnecessary. The terrifying bits of camber of the last 18 months have been neutralised. There were many places where it was simply too awkward to pedal while leaning so far over to compensate for the trike's own lean. So I completely avoided riding on the right just there. I really resented the odd passing car which forced me back into the danger zone. Now I can sit upright and pedal effortlessly along. No awkwardness or discomfort. Not even the sense of fear that I might actually tip over if I miscalculated my degree of lean. Or found a sunken place where the camber dropped away even more. This is quite a shocking discovery after all the time and thousands of miles I have covered  travelling these same lanes. My triking experience is transformed even more than the new ease of climbing. I feel so much more at one with the machine. As it urges me over every obstacle which once caused me problems. This is all thanks to the Trykit 2WD system.


[30 Sept] Yet another update: I am still delighted with all the advantages of 2WD. I have discovered that the system can be fooled if heavy pedal pressure is applied in a low gear with the handlebars turned sharply. Even a short incidence of wheel spin is possible if one tries hard enough. Over time I have detected a slight "straight ahead" tendency when pedalling hard. I can't imagine anyone finding this obnoxious unless they regularly ride with no hands on the bars. And, if they did, they would have ended up going round in circles with OWD. With 2WD you stay on the tarmac.

There is a greater pedal resistance to turning sharply at the traffic exclusion barriers (chicanes) on bicycle paths. But exactly the same occurred previously on the opposite lock with OWD. All it takes is the forethought to drop a gear or two for the likely speed involved in negotiating the barriers. Now I just drop automatically onto the smallest chainwheel.

The trike still rolls away (all too eagerly) going forwards or backwards when parked on the slightest incline. So there has been no increase in low speed axle friction. Quite the contrary. On descents the trike seems even faster. I have exceeded 35mph where my norm was 29-30mph free-wheeling down one local hill. I seem to be going faster on the flat too. I am also returning from my daily rides in better shape than ever before.

Camber has become almost irrelevant and the tiredness in my arms from constantly fighting it has completely gone. It amazes me to remember how some heavily cambered roads used to make me feel very unsafe indeed. Even after nearly a year of riding them regularly. Now they seem completely innocuous no matter how fast or hard I pedal.  I could never quite believe the degree of handlebar turn required just to maintain a straight line on a heavily cambered, straight road.

Sprinting out of the saddle with OWD was a complete joke. Even when I didn't get instant wheel spin the trike still wanted to head for the nearest weeds on the right. With 2WD it is much more like riding a bike. I now consider myself excused from climbing long hills out of the saddle. Because I don't want to risk my knees. I climbed one long and steep hill in a high gear [48 x 14] this week just to see if I could. My knees were the only part of me to complain so I'm not trying that again! It is so much easier to sit and twiddle my way uphill now.

Overall there is really nothing much to criticise about the Trykit 2WD "double freewheel" system. Climbing has become a real pleasure instead of an irritating chore. I still have to pedal (of course) but there is a real sense of going full ahead. Instead of crabbing constantly off to the right. Not to mention the former, vicious, handlebar movements of OWD on steeper climbs. I now find it much easier to maintain a high cadence in a lower gear and still maintain a good speed. The overall effect is one of it being much less tiring to climb any hill. There is a very real sense of improved climbing power for the same input.

Nothing would induce me to return to OWD now. In fact it would take an awful lot of the fun out of tricycling to have to go back to OWD. My average speed, according to my bike computer, has risen only recently by about 1 mph from 13 to 14mph based on a 2.5k recorded mileage. Given the constantly undulating nature of any ride I am rather cheered by this improvement.

The stealth, Trykit 2WD, double freehub fitted with an 8 speed Shimano cassette.
The gear cable would be much better dressed to run outside the vertical reinforcing loop.The wear on the paint suggests this was the usual route.

Please remember that all my remarks apply to riding on the right hand side of the road in Continental Europe. UK tricyclists with OWD should try to find somebody with 2WD to see if the same advantages apply. The normal road camber works in favour of OWD in the UK. My own (necessarily) short experiments with riding on the left suggest that most of my trike's nasty OWD vices were much reduced. Those required to ride on the right in their own country should consider this 2WD system a "no brainer".

I won't discuss the price of the Trykit 2WD system because we all place different values on our cycling expenses. Compared with many accessories the 2WD is likely to offer considerable improvement in performance compared with items which are merely cosmetic. A flashy chainset won't make you go an inch per hour faster than a cheap one but is highly decorative. While an almost invisible Trykit 2WD will completely transform a OWD trike.

The Trykit Longstaff 2WD conversion is considerably cheaper than the Higgins type. Making it an even more obvious upgrade over OWD. Remember that you get brand new and much stronger axles with the Higgins conversions. You also get freedom from future axle maintenance by the conversion to journal bearings. My own experience is that these journal bearings (and their seals) do not affect rolling resistance at all. If anything they offer a very slight reduction IMO. Particularly over a badly-adjusted or badly worn, loose ball, cup and cone bearing system. You can even choose to change the hub fitting of the new Higgins axles to Longstaff or Trykit 15mm dimensions. Or even have the axles adapted for modern disk or spoked carbon fibre rear wheels for time trialling. Geoff Booker will machine axles to any reasonable requirement.

In use the Trykit system is totally silent. Thanks to the many pawls and fine ratchet teeth, drive take-up is instantaneous. There is quite literally no hesitation at all. Only when walking the trike slowly under quiet conditions can one actually hear the gentle buzz of the pawls "free-wheeling".

Spinning the rear wheels via the pedals (with the trike on a work stand) it seems to take ages for the wheels to come to a complete stop. Any imbalance in the wheels will show as the wheel rolls gently back and forth slowly before finally settling. This shows just how free the entire 2WD system really is. Those presently limited to an old-fashioned, obsolete, screw-on sprocket block, or even fixed wheel, will gain the freedom to fit a gear cassette of your own choice of up to 10 speeds. Even allowing index gears with a suitable gear lever and rear changer. 

It is now two weeks since I fitted the Trykit 2WD. As of the 5th October 2010 I have put over 400 miles on the Trykit 2WD since the 23rd of September. I have not had one single reason to begrudge the cost of the system. Not one second of doubt as to its amazing value in improving the performance of my 1954 Higgins trike quite beyond belief.
Dec 5th update: There are regular positive comments on the Trykit 2WD in the triking diary chapters which follow this one. If there is any doubt as to the efficacy of 2WD then look for my December chapter when the snow arrived. Enlarging the image below (by clicking on it) will show my direct ascent of a snow covered hill. Rising in a series of steps it is quite steep enough throughout to be tiring to climb at any time. On snow I was able to maintain a reasonable speed without any wheelspin.

First, winter, direct ascent of the north face with Trykit 2WD.

I have not needed to add wider, knobbly tyres for the snowy conditions. (as planned) Because there is simply no need. With my existing 23mm wide, dead smooth, rock hard, Bontrager Race Lite, 700C tyres I can climb quite decent hills in several inches of snow.

Though one is completely unaware of it, the moment one wheel starts to slip, drive is instantly taken up by the other wheel. The only way to achieve wheelspin is to turn the handlebars hard to the left or right. Otherwise it seems almost impossible. There is a very steep slope at a supermarket which I visit regularly. It must be about one in four or 25%. This slope has often been covered in snow and ice recently. Even when I'm in a very low gear I simply cannot make the wheels slip on this slope. Absolutely amazing!

Watching cars sliding about as they try to climb lesser slopes reminds us that the differential falls flat on its face in slippery conditions. Instead of each wheel assisting the climb they fight each other. The moment one wheel starts spinning all the drive is sent to that wheel.  The opposite occurs with the Trykit 2WD. All the advantages of four wheel drive seem to be achieved with the Trykit two wheel drive on a trike. If the handlebars are kept reasonable straight then both wheels drive together. The grip provided is astonishing. One can stand up on the pedals on a snowy or icy slope and accelerate smoothly without the least wheelspin. No wheelspin at all!

Last winter I was denied many of my regular, minor road routes because I only had 1WD. I couldn't maintain momentum on the same hills with the same tyres due to wheelspin. The advantages of two wheel drive are very obvious. I can continue to use my year-round tyres with their lower rolling resistance on all surfaces. It may be that the skinny tyres can cut through the snow better than wide tyres. Which would probably still sink in just as far. The wider tyres would need to compress a broader track in the snow. So the wider tyres would offer higher drag in all road conditions.

Click on any image for an enlargement. Back click to return to the text.

23 Sep 2010

Trykit Two Wheel Drive System



Trial assembly of the Trykit Two Wheel Drive system and journal bearings on the new axles.
Whoops! Experts will notice I have fitted the Trykit 2WD freehub back to front in this mock-up arrangement for the photograph. The locking ring should go behind the sprocket block/cassette.Not in front. In use, the upper axle in this image fits in the other side of the Trykit double ratchet, freehub body.


The combination of riding on the "wrong" side of the road (compared with the UK) and regular axle rebuilds was leaving something to be desired. On steep climbs the front wheel would go light on every pedal stroke and then jerk hard to the right on opposite lock. This was exacerbated by holding the handlebars at the centre. Leaning forwards onto the brake hoods helped but was certainly not ideal for my breathing.

Experimentally moving over to the left side of the road (on quiet lanes when there was no traffic) immediately neutralised this bad behaviour. The problem is that one can only rarely ride on the left with any degree of safety in Denmark. It is expected that even a (slightly eccentric) English tricyclist rides on the correct (right) side of the road.

The original Higgins axle cones were showing signs of wear and required ever more regular dismantling and greasing to keep the axle quiet. The embarrassment of passing another cyclist with the axle clonking like an old-fashioned, clothes wringer was really getting on my nerves. I could have ordered some new axle cones from Chris Hewitt but I liked the wonderful silence and lack of maintenance of my Longstaff trike conversion.

So, after months of worrying about the considerable expenditure, I finally ordered a Trykit 2WD system. Which I would fit myself as a compete, made to measure "kit".  Normally Geoff Booker of Trykit would like to have the trike in his workshop. So that he could measure up accurately, make the parts to fit perfectly and then assemble them on the trike for the customer. I couldn't afford the cost of two way international transport for my trike. I also had the tools and skills to measure my Higgins accurately in the first place and then fit the device myself. Thankfully Geoff agreed to supply his 2WD system on this basis.

Apart from the special, double-freewheel, freehub body the DIY kit would include new axles and sealed journal bearings. The latter would be fitted into modified, bottom bracket, bearing cups. Lightweight alloy bearing cups were offered but I opted for the much cheaper, modified, secondhand bearing cups. While I do like the idea of a lightweight machine, the difference in weight between steel and alloy cups is hardly likely to matter to me. Not when compared with my huge shopping bag and "covers all risks" tool kit. I haven't weighed it but let's assume 5lbs minimum on every trip even before the shopping is stuffed in there.

 I use shopping trips to many different supermarkets as my goals for each daily ride. In Denmark most large, rural villages have at least one supermarket. Often more than one. This gives me quite a large choice of shops and routes within a fifteen mile radius to avoid my routes becoming stale. Fortunately I enjoy beautiful, rural countryside and quiet lanes to all of these shops in all directions.


Preparation and Assembly of the Trykit 2WD system:

The big shopping bag was removed from the Higgins. The wheels loosened and then the trike was lifted onto my cheap but excellent (£20) Lidl work stand at full height. I might as well be comfortable while finding my way around my first attempt at fitting the 2WD system. Lifting the trike onto the work stand without the heavy bag in place is really no problem at all.

The Higgins stripped of its axles and bearings rides high on the work stand. I should have tied the chain to the rear loop as well as the top to keep it well out of the way. I also removed the rear gear changer and hanger after I took this picture.

Oh, the excitement! The Trykit  package has finally arrived! I was (almost) tempted to do an "unpacking" video. Like the sort of thing they enjoy on YouTube. I'm afraid you'll have to make do with a few still images instead. ;-)

BTW: Trykit is Geoff Booker. He works alone, with the help of his wife. So delivery times are flexible depending on his workload and his (local and international) trike racing activities. In my case it took about a month from placing my order. This seems very reasonable considering that two precision axles had to be made to fit my trike exactly. (Trike axle width, or track, varies considerably so no two axles are likely to be identical)  No doubt an order for a Trykit trike has higher priority than a "humble" 2WD system. I'm really not sure. The chap has to eat as well as keep the world of international triking rolling along nicely.

The teaser shot! Nicely wrapped considering all the hidden components are tough steel.

The Higgins 2WD kit in all its glory! 

Beautifully machined with nicely waisted axles to save a fair bit of weight. This also provides a little flexibility and arguably greater strength in use. A stiffer axle would merely push the greatest loads out to the short distance between the outer bearings and the hubs. A slightly more flexible axle would help to take some of the road shocks from the wheels. Dissipating it safely in the much greater axle length between the bearings where the axle is much more lightly loaded. The axle can be thought of as a lever with a fulcrum at the outer bearing. The ratio between the short length of axle beyond the bearing and hub relative to the length to the inner bearing gives some idea of the local loads involved. The axle must resist the weight of the rider and any road shocks applied through the wheel. The majority of the bending forces occur in the short distance between the outer axle bearing and the inner side of the wheel hub.

My Higgins has a single, fixed, bottom bracket cup behind the cassette. So one was provided in the "kit" already fitted with its journal bearing. Many more Higgins trikes have an adjustable bearing cup behind the sprocket block instead. In the image above, the special, Trykit, double-freewheel, "freehub" is shown on on the left with its adjustable, cassette, stop ring.

A closer view inside the Trykit 2WD body. With central blanking plate and the pawl carriers with hex-shaped cut-outs to match the inner axle ends. Note the way the axle extends at the full 17mm diameter right out to the conical section which fits the matching female cone of the Higgins hub. The parallel section, to the left of the conical section, is actually hidden within the wheel hub.

Inside the special, Trykit, 2WD freehub there are two pairs of pawl carriers. With three pawls each per independent axle drive. Six pawls in total per axle. The large female thread just inside the body is for the standard, male Shimano Cassette locking ring. This ring also holds the top gear sprocket(s) in place as it clicks down tight using the special splined tool. These parts are typical freehub mechanics and safely avoids unique engineering principles. With possible catastrophic redundancy if the parts became suddenly unavailable.

Geoff is to be highly commended for his common sense in his 2WD design. Bicycle free-hubs are in universal use on racing and mountain bikes. So are likely to remain in use for many years to come. So matching multi-sprocket (Shimano standard) cassettes and locking rings, and their fitting tools, are all likely to remain available for decades.

Just look at the sheer quality of machining of the Trykit double freewheel body!
Geoff uses spark erosion to produce the internal ratchets. The number of teeth on the ratchets has been optimised to match tooth size and longevity.

Shown above: A trial assembly of the two axles into the body. The axles are a snug push fit in the sealed, body bearings and pawl carriers. The locking ring sneaks up behind the cassette and holds the cassette in place as if there was a standard Shimano freehub shoulder. Except that Geoff Booker (the proprietor of Trykit Conversions) has provided an adjustable shoulder in the form of a screwed ring. Both clever, flexible and practical. Even the ring is a standard bottom bracket, bearing cup, locking ring.  So again, no risk of early redundancy through loss of a simple part of the whole.

The Trykit double freewheel body internals showing the double pawls in their carriers, 27-tooth ratchets and central spacer. The central spacer is to allow the owner to safely drive out the pawls and bearings for maintenance. Spare pawls and springs are available if needed. The sealed, journal bearings are affordable, standard designs available globally.

These are likely to last a very long time because they are all safely sealed and only turn (as bearings) when free-wheeling under almost zero load. The rest of the time they merely support the freehub and cassette concentrically on the inner axle ends. While pedalling, the entire trike axle arrangement rotates as one. Road wheels, half axles, freehub, bearings, pawl carriers and the multi-sprocket cassette. Although these bearings have to resist chain loads they are easily large enough for the task. On a bicycle, a freehub bearing rotates constantly on the rear axle whether you pedal or freewheel. A normal freehub's bearings are almost pathetic compared with those used in the Trykit body.

Light grease is recommended for lubrication of the Trykit freehub body pawls. These make a very quiet but pleasant buzz when free-wheeling at walking pace. Though it has to be very quiet indeed to hear this sound. I don't freewheel much so I rarely hear anything at all from the Trykit 2WD system and its axles. 

I believe this is the Mk4 version of the Shimano-fit body as Geoff finds new ways to improve his product. Shimano cassettes up to tens speeds are compatible. With a minimum of an 11 tooth, top gear sprocket allowed in the latest iteration of this very special, Trykit, double freewheel freehub.

Geoff also offers special axles to convert a Higgins trike to a 15mm bore Trykit or Longstaff hub fitting. These have larger axle dimensions than the Higgins where it really matters. Offering much greater strength at the cost of slightly increased weight. Though hollow axles can mitigate against the extra weight without much loss of strength.

I had bought new, Higgins-fit wheels from Geoff only 9 months earlier. So was in no hurry to discard them or leave then lying around unused. So I chose to continue with Higgins-fit axles. Denmark has zero demand for spare trike bits and pieces. Postage to the UK is prohibitive. So it is not easy to put anything on eBay(UK). Geoff's design for the axles easily overcame the bottle-neck in the original Higgins cone section. So I was confident the new axles would easily outlast me despite my choice of the smaller section, Higgins fit hubs and axles. 

A comparison shot of the Higgins original axles and components with the Trykit parts just above. The clever Trykit 1WD freehub adaptor kit lies at bottom left. (now unused) Here, the Trykit 2WD body has been fitted into a 7-speed Shimano cassette. Now modified to a 13-28T 7 speed from an 8 speed, 11-28T by the substitution of a larger, single, top gear sprocket instead of a double. I hardly ever feel the need for a very high top gear even on the steepest descent. I would much rather have a closer ratio, 8-speed 14- 28T cassette.

The Trykit lock-ring has been snuggled up against a spacer ring behind the Shimano cassette. The Trykit 2WD body will take cassettes up to 10 speeds. My modified, 7 speed cassette found the thread just slightly too short. All it needed was a simple packing ring to take up the free play. Such spacer rings were once widely available from better bike shops for spacing bottom bracket cups.

Here I am checking the vital clearance between the inner axle ends with a 4mm Allen key. Using a round, 4mm rod or drill shank would have been slightly more accurate.

BTW: On Geoff's advice I regularly checked the freedom of the axles during assembly by rotation with my fingers. This helped to ensure there was no binding of the bearings through over-tightening of the adjustable bearing cups. A tiny amount of end play is desirable for long bearing life. Though too much end play might affect indexed gearing.

As can be easily seen in the image above: My left, axle bearing cup is non-adjustable. So the right side cup was carefully adjusted to just nip the hex key very lightly. Note that both outer axle bearings in their screw cups were fitted to ensure the axles were properly aligned for this axle spacing measurement.

The hexagonal, inner axle ends fit the twinned pawl carriers inside the 2WD body. The turned sections alongside these fit the 2WD body bearings. Which are slightly smaller bore than the axle bearings. As can be seen by the larger, parallel section on the right protruding through the axle bearing. This clearly "steps down" in diameter from the 17mm bearing bore to the 15mm cassette body bearing diameter on the right axle stub.  

Trial assembly: Note the "deliberate" mistake! I forgot the locking ring on the right side adjustable bearing cup! So I had to withdraw the right side axle again to be able to fit it in place. This is not too difficult if the wheels nut is fitted to give yourself something to pull against. The outer bearing cup has to be removed first or the axle will not come out.

Once in place I watched the adjustable bearing cup carefully as I tightened the lock-ring. Just to avoid it turning and undoing my earlier 4mm measurement. If you find yourself  assembling one of these 2WD axles yourself then do fit the lock-ring first. Then tighten it properly before being fully satisfied with your final 4mm measurement! You have been warned! Do as I say! Not as I do! ;-)

The right side, adjustable cup, lock-ring is now safely in place. The chain has been tied up to the upper, axle, reinforcing loop. My poor old Higgins has suffered some cosmetic damage to the paintwork over the years. If my trike was as immaculate as are many others I would have protected the reinforcing loops with taped on paper or cardboard before starting work. I treat my trike as something I ride every day at the cost of some slight loss of appearance. If I started worrying about the paintwork I'd need to fit a proper rear carrier for my huge shopping bag. Then spend hours cleaning the trike instead of adding more miles. Your mileage may vary. :-)

Ready for  the road! With the Suntour ARX, rear gear changer refitted to the Trykit hanger. Followed by a quick wipe over to remove the oily fingerprints from the trike frame for the picture. Had I been more fastidious, and less impatient to try out the 2WD, I would have cleaned the cassette thoroughly before fitting it.  It was now 7pm. Dinner and dusk threatened! 

Note the extra clearance between the outer bearing cup and the Trykit hub. After discussion with Geoff it was decided that I could risk an extra 6mm of extension (over the usual clearance) beyond the outer axle bearings. I was hoping for a little extra width on the rear wheel track for greater lateral stability on rough roads. Plus room for a cup-adjusting spanner without removing the wheels. The diameter of the axle is 17mm where it fits through the axle bearings. This diameter is carried right through to the conical seating of the Higgins fit hubs. Unlike the Higgins originals. Which are actually stepped and reduced to two flats to take the removable cones at the most highly stressed point anywhere on the original Higgins axles!

A Longstaff axle is much beefier and could more easily accept the extra loads from spacing the wheel hub just a little further out beyond the outer bearing. The Higgins is strictly limited by the internal size of the original tubular axle casing between the bearing cups. This short, visible axle section is the most heavily loaded part of the entire machine. One cannot just keep adding axle extension without very serious risk of failure. Not even with high quality, modern steels. The axle would bend very slightly on every bump. Eventually and inevitably it would work harden the steel. Leading eventually to fatigue. Then one day it might just snap off without warning! Probably when one is many miles from home just as a heavy vehicle passes.

A broken trike axle is too awful to contemplate in traffic! It is a disaster at any time and one should check the wheel fixing nuts regularly to avoid accidents. I read about one racing tricyclist who forgot to fix the wheel nuts on his trike just before a race. He had severe injuries when the wheels literally fell off! It's a long way down when you suddenly lose over a foot of axle height between you and the vicious tarmac!

After reading about trike axle breakage online I must admit to having had a real sense of insecurity when running about on the original 56 year-old Higgins axles. Every time I was passed by a six axle, Continental, HGV colossus I would worry about the Higgins axles. Every time I exceeded 30mph going downhill I would worry. New axles in high quality steel, without the stress-raising sharpness of the cone seatings, are a real bonus with the Trykit 2WD.

I could have bought new just  a set of OWD (One Wheel Drive) axles from Geoff but chose to buy the 2WD system at the same time. I knew I'd want 2WD sooner, rather than later. Then I would have no use for two pairs of redundant, OWD axles when I finally made my mind up.  Special new axles are required for the 2WD system because they must reach inside the 2WD body. They must also accept journal bearings.

I shall discuss my Trykit 2WD riding experiences in the next chapter: Which, thanks  to the strange logic of reversed blog posts, is actually first. So you're probably reading this chapter long after you've read about my riding my trike with Trykit 2WD fitted. 

A link to 2WD maintenance instructions on the Trykit website:


Another of my blog posts discussing 2WD maintenance one year on:


Later note: I discovered something much later while playing about with 10 speed indexed gears on my old Higgins: When ordering a 2WD system for an old Higgins trike Ask Geoff to design the new axles to bring the largest (bottom gear) sprocket to the centre of the reinforcing axle cage. This will allow the largest possible sprocket to be fitted, if desired, when using a 9 or 10 speed cassette. This is easily taken care of my extending the new, left axle slightly and shortening the new right side one. This will help to bring the 2WD freehub to the centre of the axle reinforcing loops. If this is not done the largest sprocket will lie too close to the reinforcing loops. Limiting the largest bottom gear sprocket to only 26T in my case. This forces the use of a smaller inner chainring to make the gear ratios low enough for climbing steep hills while maintaining a high cadence.  

Click on any image for an enlargement. Back click to return to the text.


18 Sep 2010

Lady Higgins

Yet another trike has come up on eBay. A 1965 Higgins Lady's model with Sturmey-Archer internal (hub) gears and Higgins specially extended axle reinforcing arrangements to match.

RARE VINTAGE HIGGINS TRICYCLE,3 WHEEL ADULT BIKE on eBay (end time 26-Sep-10 22:05:21 BST)

The lady's step-through frame would suit those needing easier access than the men's model when mounting the tricycle. Such a machine offers the advantages of the handicap tricycle but with much reduced weight. Making it much easier to manoeuvre when dismounted and much easier to pedal when climbing hills. At the same time it offers the fittest cyclist the full triking experience.

No doubt a skilled frame builder could easily change the top tube to a horizontal one if desired.  No new lugs are involved on a fillet-brazed frame like this one. The only practical downside I can see to the lady's model is not being able to hang a leg over the missing top tube when cornering hard. Though the saddle could probably substitute. 

I have enlarged the original eBay auction images in PhotoFiltre from 500 x 375 to 800 x 600. Slight increase in gamma and contrast have been applied to crisp up the images slightly when enlargements are viewed. However, lost resolution cannot be regained.

Overall view showing capacious rear basket.

Higgins Head badge

Left side overall view

Badged head tube, forks and brakes. (Centre-pull and cantilevers)

A close-up of the braking arrangements. Mafac 'skeleton' cantilevers on braze-on bosses on the forks with a Weinman centre-pull mounted up front.

Chainset, pump and rear basket. The small chainwheel will provide comfortably low gears.

Underside of eccentric bottom bracket showing serial number and shell clamping bolts.

The Sturmey-Archer internal hub gear and extended axle reinforcing loops. The design was intended to allow the standard S-A cable to be used. The same as on bikes fitted with these hub gears. The S-A axle is also supported on the right to resist the heavy loads applied through the chain by the rider. A remarkably simple and clever design which provides similar axle strength to normal trikes without much increase in weight. It also allows the use of a Sturmey Archer hub gear without any major modifications or the use of a lay-shaft. The SA hub gear was appreciated by many for its reliability and freedom from maintenance compared with dérailleurs.

The Higgins brass badge and the SA gear adaptor/extender on the right. The hollow, tubular adaptor is open on one side allowing the S-A hub gear to be bolted to one end and the left axle drive to the other. While still allowing both fixing nuts to be easily accessed with a ring spanner. (wrench)

For those of you wishing earnestly that this was a gent's model:
Just for a bit of fun I drew in a trendy, sloping, gent's top tube and "removed" the original top tube. Just to show how the trike would look as a gent's model.  All it takes is a bit of imagination and a skilled frame builder. No lugs required on a fillet-brazed frame. I'm sure Geoff Booker at Trykit could apply a little of his "magic" here. ;-)

This trike eventually sold for only £156. Probably the low price was due to the trike residing on the Isle of Man. The cost of delivery to the UK being a factor for many potential buyers.

Click on any image for an enlargement. Back click to return to the text.

16 Sep 2010

Bright berries and fallen leaves

16th September 2010 48-55F, showers, sunny periods, wind building to gales again. I got up early and was on the road by 7.30am taking advantage of a window of opportunity. The roads were littered with leaves and twigs from yesterday's gales. It rained a couple of times but I just put on my polyurethane, proofed jacket and pedalled on. I was getting quite tired towards the end because it had been so long since breakfast and the headwind was increasing rapidly. Then I punctured a couple of miles from home but only wasted five minutes before I was on my way again. 34 miles.

17th 48-55F, breezy, overcast, showers. It rained more or less continuously all the way round. Whenever I decided to take my waterproof jacket off it started raining again. Luckily my wife suggested I put on one of my long sleeved polyester vests before leaving. Under a shower proof  jacket and cycling jersey it kept me very comfortable and warm despite the jacket and other clothes (and vest) being wet.  My forearms had been getting cold when the jacket was wet on previous days. Which made me feel more uncomfortable than necessary. Time to adopt the layer principle again as temperatures sink.

Towards the end it started raining really hard with standing water right across the road and a road-wide rushing stream where there was any sort of an incline. The water was pouring through my cycling shoes and out of the perforated soles. It wasn't very nice being "pressure washed" by every passing vehicle but I was committed to getting home. The lorries were the worst and drivers didn't care that they were putting up a huge cloud of solid spray. This didn't matter much inside my waterproof jacket but it made my bare legs wet and cold. I was an idiot not to have worn my new overshoes today. They might have kept out the worst of it. The fingerless mitts will have to be replaced by gloves now.

I really need a proper flap on my front mudguard to stop water being thrown straight up at my feet. I must also be much more disciplined about covering the Brooks saddle than I have been to date. I am just not used to riding in the rain thanks to my remarkable luck so far. The problem is the saddle getting wet when I get off to shop. Not because it is uncomfortable getting back on when wet (it's not) but  it might deform. I carry a polythene bag for the purpose but it is often too much trouble to find it in a bag full of shopping.  It will have to go into the zipped pocket with the padlock as  matter of routine for supermarket stops.

I really need a longer ride to get my average back up after the rest days but the weather hasn't been kind with gales every single day. The rain I don't really care about. Though no rain is obviously better and sunshine a real bonus. I have noticed that my legs have lost their continuous feeling of "heaviness" since the rest days.

On a quiet lane I disturbed a large deer asleep in the overgrown verge. I didn't see it until I was right on top of it and it didn't hear me coming. It jumped to its feet and ran off across a bare, earth prairie as fast as it's legs would carry it,  zig-zagging as it went. Until it was so small as to be almost invisible.  29 miles today.

Sunday 19th September 50-57F, breezy but getting windy, sunny periods. Two shopping trips for 25 miles total. Half an hour of weight training with 24 x 10 kilo weights.  Loading and unloading a shopping trolley then into and out of the car into storage.

The I-gotU GT-120 didn't record anything at all on the second trip. My £7 CSI wireless bicycle computer is failing to register mileage or speed reliably despite careful adjustment of magnet and sensor. Perhaps the battery is flat? It has recorded 1860 miles since new. Equivalent to only two months worth of rides @ ~30 miles per day. I have now been caught on the last leg of my last three day's rides by very heavy rain. An odd coincidence?


Dreirad has kindly supplied further images of his immaculate Higgins:

The reflective side-walls of his tyres certainly earn their keep.

The rear tube cluster with beautifully radiused fillet brazing.

20th September 50-54F, breezy, becoming windy, raining. The cornflakes run found all the weaknesses in my waterproofing. The shower-proof and windproof jacket was only just. I donned an old polyurethane proofed jacket on top and became thoroughly wet to the core. I tried the Aldi overshoes for the first time and found them completely hopeless. No better than wearing a large pair of socks over my cycling shoes and probably less warm.

The final straw was waiting in a queue in the supermarket and getting cold. From then on I didn't warm up again and felt shivery. I had my long sleeved polyester vest on under a cycling jersey with the windproof jacket on top. Four layers which proved not to be neither waterproof, warm enough nor windproof enough for the conditions.

My cycling shorts were so wet the chamois lining turned dark. My socks and shoes were saturated and squelching on every turn of the pedals. I leaned right over on a sharp corner and soaked my shorts in a second from the back wheels. No only cold and uncomfortable but it made the saddle wet.

Lessons learned: I need a much better top jacket for rain. No more bare legs when rain is threatened or already falling. They act as radiators to make me cold when wet. So I shall have to get all the long legged skiing tights out now.

I badly need a mud flap for my front mudguard. Proper overshoes for the wet. Perhaps a light wool jumper to go under the windproof jacket. Carry the waterproof trousers in my bag all winter. I left them at home thinking it wasn't cold enough to take them. They would have protected me from side-wind blown spray off the back wheels. They would have kept me warmer over the tights.

The cycling glasses with orange lenses were good for keeping the driving rain out of my eyes going into a head wind. Though they tended to mist up quite a lot inside the hood of the "waterproof" jacket. A peaked cap would have helped more than a sopping wet skull cap by protecting the lenses more. Yellow lenses would have been even better. Being a bit more cheerful under such a heavy overcast. The CSI bike computer is now malfunctioning constantly. 34.2 miles measured by both GPS loggers.

Another 10 miles later. Damp but not raining. My Tahoe shoes were still so wet I had to swap the cleats onto my Shimano road shoes. Okay for a short run but still too "pointy" for long term comfort. Awful to wear off the trike. I saw and heard a jay in the woods.

21st 50-58F, sunny periods windy. A completely different day from yesterday with lots of sunshine. The bike computer and the I-gotU logger both misbehaving badly. I'm going to try lifting the wheel sensor up the forks and moving the spoke magnet to match. This will reduce the distance between the wireless sensor and the display head on the handlebars.

The GT-120 logger is fully charged but refusing to turn on reliably, show any lights or record a trip. Yesterday it it failed to record then refused to clear the memory. My hip is hurting. Probably the "weight lifting" on Sunday.  Only 24 miles so far. I hope to get out later.

Moving the wireless sensor cured the speed and distance section of the computer. The GT-120 is also sorted thanks to repeated switching on and off.  Another 14 miles.

Mr Higgins stops to admire a serpentine fish ladder at Brobyværk.

22nd Sept 48-57F, light head winds, increasing, sunny. Perfect cycling weather. Rode to Fåborg. Disturbed a deer in the woods. Axle clonking again already. Pottered about in the shops for half an hour then back home again by another route. 45 miles.

A better view from the railings.

23rd 50-61F, light head winds, sunny. Another perfect day for cycling. Mist hung over the fields under a blinding sun. Very atmospheric. ;-)

Cattle grazing on top of the the second highest "mountain" on Fyn. 

My Trykit 2WD "kit" has arrived and needs to be picked up. So I shall have to go out again. Only 28 miles so far. Plus 8. Plus 5miles later testing the 2WD. See my separate posts on 2WD.

24th Sept. Overcast, 55-60F, light winds. A morning ride of 24 miles to test the 2WD and another of 17 miles in the afternoon. Very positive results. Once tried there is no going back to1WD. I saw another Jay. My "cold" may be finally on the mend. How many weeks are "colds" supposed to last? The roads are covered in mud pats from all the tilling, spraying and seeding. Very uncomfortable to ride over. A contractor is going around with a special machine cutting all the hedges to the ground. Hopefully this means they will regrow but it leaves the roads exposed to snow drifting and the fields to topsoil loss in a gale.

25th 48-54F, sunny, winds very light. I disturbed a pair of deer in a lane where they were sleeping in the overgrown verge. They seemed unsure what to do about me and hesitated before bounding off to a fold in the field. Where they stood and watched me in the brilliant morning sunlight.

On the same narrow lane the camber is quite extreme. Until today I always rode in the middle of the road to avoid the camber. Despite the delights of the quiet lane it was very awkward to pedal along on on the right because I had to lean over so so far to compensate. With 2WD I had no need to lean at all. I just sat upright and pedalled perfectly normally.

Emboldened by this discovery I experimented on other lanes with similar camber. There were many places where I would get angry if a car wanted to pass because it felt so dangerous in some places.  Now the fierce drops in the camber seem no worse than any other road. What is so surprising is that I no longer need to lean away from the verge. The trike keeps going in a straight line without trying to dive into the roadside nettles and hedges. You cannot imagine how much more relaxed this makes a ride along these lanes. Steep camber is very commonplace indeed on the minor roads and lanes. There are very few drains (at all) so the roads must be emptied into the verges when it rains. This requires a lot of camber to stop the road becoming a stream bed and causing damaging flooding at the bottoms of hills. 22 miles so far. Another 24 miles pm.

I just found this chart from the VTTA on the Trykit/Oxonian website showing standard TT times related to age.


It seems that as a 63 year-old tricyclist I am considered the same as a 74 year old cyclist. No wonder I'm feeling old!  It seems I am supposed to be able to do a 10 mile TT in 33.18. Are they kidding?!? My average speed is still only 14mph according to my bike computer. Whoops! That puts me in the 42 minute bracket! (blush) Now I can say;  "I'm 94, you know!" :-)  Isn't it odd they don't list solo shopping trolley times by age? :-)

26th September. A grey and wet morning with a dry window forecast for the afternoon. 54-58F, rather breezy from the NE which is quite unusual.

The proof of the VTTA pudding beckons: I have measured an 8km stretch of fairly smooth main road with a roundabout at one end. (I used Google Earth with a very large image scale to measure the route exactly but ignored the circumference of the roundabout)  A round trip of 16.1km = 10 miles. There is a cycle lane for the full length behind a protective white line. Which offers a reasonable level of safety from being shunted from the rear. Very few Danes keep to the speed limits.

There is unfortunately a fair old hill rising up to the roundabout which is on a hilltop. Though both ascending and descending should nullify its effect. The start is a good distance from home so I should be well warmed up before I start. There is a very clear landmark at the start to avoid any confusion.

The same main road offers lots of flatter, alternative 2 x 5 mile routes but none of these offers a roundabout turn. If the road is busy I could waste a lot of time waiting to turn safely. Unfortunately there is no perfectly flat, 10 mile, one-way route. The road is not a dual carriageway as these are rather rare in this part of Denmark. Though it is very wide. Easily wide enough to avoid problems with traffic. Sunday should be almost totally free from juggernauts.

I could put the trike on the car bike rack but it feels like cheating. I shan't bother with tri-bars for the first attempt. I'm curious to see how I perform against the clock. It would be better if the wind was much lighter but beggars can't be choosers. It will be at about 45 degrees to the road rather than head on or a tail wind. Though it will vary a little in its angle over the route. 

35 minutes dead by my watch! Not bad for my first '10' in over 45 years! The bike computer ticked over 10.1 miles just as I crossed the line. So I hadn't measured short. 15 minutes at the turn was a good balance and gave me a valid reason to go on trying on the return. Shame the course was anything but flat in reality. It was more like a very long slow descent then a steeper climb up to the roundabout. Then a long climb all the way back to the finish after the descent from the roundabout.

My trivial excuses for not doing better: I used ordinary dropped handlebars, great big 10lb shopping bag at the rear and a strong cross wind. I was being blown about quite a lot. At ~60F I was too hot in my long sleeved vest under my cycling jersey. I tried too hard getting there on the big hills and into the head wind instead of taking it easy. So my legs were already a bit tired from the last long climb. I should have had a rest but started off straight away. I was too full of sandwiches and fruit from lunch and got indigestion and then a stitch. Which is unheard of for me. Probably caused by riding on the drops for too long. The cycle lane was covered in small twigs and leaves. I still have a chest infection and snotty nose from my weeks long cold. Oh, and I had a full mudguard on the front. Whoops! I forget to mention the tyres were not pumped up hard. I couldn't believe how soft they were this morning when I checked them.

While on the ride I trashed my legs on the long climb up to the halfway roundabout. So had not much left for the descent. My back hurt from being bent over too long on the drops so I had to sit up for quite a while going both ways. Tri-bars would have saved my back. I'm not used to riding on the drops for more than a mile or so.

I can solve most of these problems by leaving an hour after breakfast. Pick a day without wind. Lose the big shopping bag and fit the add-on tri-bars to the drops. I shall have to learn how to use the trip timer on my bike computer for  greater accuracy in timing.

10 miles to get to the start, 10 miles TT, then 10 miles back home again. Plus 10 later for 40 in total. I am learning to massage my own legs from watching YouTube videos. Though I haven't tried oil yet.

27th 48-53F, heavy overcast, windy. Just a 15 mile shopping trip am.. 28 miles later. I found some steeper hills climbing out of a valley which were good fun with 2WD. Then I climbed a long and even steeper gravel drive up to a garden centre. With the 2WD it was effortless despite the potholes and general roughness.  Not a very nice day with strong winds and dull grey sky. Cooler too at 53F but at least no rain.

28th 48-52F, mostly sunny, very windy. So cold I put on a thicker jacket. Kept it on until half way around today's loop. The tyre which was on the drive side is down to the canvas for most of the circumference. Only 24 miles. I was out in the car in the afternoon but couldn't get hold of any 700x25 Bontrager Race Lites in blue. I fancy a slightly wider tyre for the winter and have nothing to criticise about the Bontragers. 7.5k miles one wheel drive with only a couple of pinch punctures on 700x23 all round is an astounding performance. Particularly considering the dreadful state of the roads I ride every day. I  regularly go off  the tarmac on gravel paths and unmade roads with embedded rocks.Many supermarkets have a 2" high step out side the ramp up the pavement to their car parks. I'm sure this is the cause of my pinch flats.

29th  44-54F, fairly light winds, sunny. I stripped the rear axle again trying to solve an intermittent drive problem. I felt a sort of tick or knock through the pedals every so often which I couldn't explain. I lifted the trike onto the stand and tried every gear but couldn't find the problem. While I had the axle dismantled I double checked the end clearance of the half axles with a 4mm rod. It was still perfect from the first time.

The axles seem to have freed up a bit in use. Any worries about journal bearing seals binding were groundless as the trike will still run away on the slightest incline. I found nothing wrong but just as I put the last wheel on I noticed a broken link on the chain! One side plate had severed across the middle! It was a cheap 7 speed chain I bought from a chain store to save wasting money when there was still a lot of salt on the roads. So today I bought an Sram 830 8 speed chain while I was in town. They were having a sale on all their clothing so I bought some foam overshoes for half price which would go easily over my size GB11/EU46 Tahoes.  

Either I am getting stronger or the trike is running better than ever. Though I'm still coughing and clearing my throat all to frequently from the never ending "cold". It is that difficult time of year when temperatures are falling and it is all too easy to overdress and get sweaty. Then removing the windproof jacket exposes me to chilling by the damp clothing underneath. It doesn't help when it has been so windy at the same time since it is easier for the cooler air to penetrate my thinner clothing. Then conditions change rapidly when I turn in or out of the wind. At least I have a much wider choice of modern clothing than I did last autumn. Only 25 miles today.

30th September 42-52F, breezy, sunny periods. I rode to the city to try and find some tyres. Shop after shop and none had Bontrager Race Lite in 700x25. But nothing even in boring black. I've ridden on black tyres for nearly 60 years. If blue is made then I want blue! I went to about 10 shops. (I lost count)  Now I'll have to buy them online. Which is silly. Next time I want a real bicycle shop there won't be one there!

This was the first time I've been to Odense on the trike. The cycle paths were not ideal for triking with lots of sharp turns, narrow sections and weird inclines and ramps. Large potholes too! Perhaps the intention was to keep cycle speeds down? Unbelievable how many idiots rode two abreast or in the middle of the cycle path. I had a blister on my thumb from dinging the bell! ;-) I got some odd looks and smiles as well.  51 miles and still no shopping! 

Click on any image for an enlargement. Back click to return to the text.

13 Sep 2010

Trike brakes.

 Most trikes use two normal "bicycle" brakes at the front. Only a very few riders use any kind of rear brakes. Though hub brakes have always been available and were used on some trikes at the rear. Rear disk brakes are a relatively new phenomenon but have become the norm for massed start races for "disabled" trikes under UCI rules.

Only occasionally were side pull brakes fitted at the rear on crossbars fitted across the seat stays. I experimented with this idea myself but quickly gave up due to the rear wheels locking the moment I applied the brakes in the wet. I had steel HP rims at the time so that may have affected the matter. Others seem to like the idea. Dave Overton used a similar set-up on his trike at Warwick. Where he came second.

Dave Overton's trike at Warwick with (and using)  twin rear, side-pulls. 
Image from British Cyling's Flickr webpage. (Cropped and resized)

It occurs to me that a pair of side pull brakes could be incorporated into the compulsory, rear "safety bumper" to pander to the lunatic UCI rules for handicap massed start racing and (now) TT trikes as well. Such an arrangement would be much cheaper than a pair of disk brakes and very much lighter in overall weight. The bumper must be fitted anyway. So why not incorporate the brakes? Disk brakes require very expensive mods to standard trikes.  They may also drag or have "difficult" braking behaviour.

An added "crossbar cum safety bumper"  is just extra dead weight. Much like the brain dead idiots on the UCI rules committee in relation to cycling. They have made themselves indispensable to the designer jewellery branch of bicycle design. So we might as well play them at their own game of constantly moving the goalposts. 

They say that two independent brakes on the rear wheels are a requirement. No mention of standard stirrup brakes being excluded. Every road racing bike on the planet has cable-operated, stirrup brakes. They are well proven over a century of use in all types of cycling. All they require is a twin cable handlebar lever to be operated in perfect balance. Side pull brakes operate smoothly without any nasty vices. The total cost of adding these brakes to a standard trike can be as modest as the depth of pocket of the rider or their sponsor. There is a huge selection of brakes to choose from. No doubt Geoff Booker of Trykit could easily adapt his UCI rear bumper to take a pair of side-pulls at very little extra cost. 

The White Winter in Denmark, last year and this, went on for literally month after month. The roads were continuously iced over, covered in snow or just very wet on every ride. I rode with twin front brakes on the Higgins with skinny 700 x 23mm Bontrager tyres all round. I rode over sheet, black ice, going downhill many, many times and never felt the need for rear brakes. The trike stopped quickly and safely under all circumstances with the front brakes alone. 

Had I fitted rear brakes might have been tempted to use them. Had I so much as touched those back brakes under the difficult conditions I faced, every single day, for all of those months, I would probably not be here to write this blog. The rear wheels would have locked instantly due to their perfectly normal, light loading. With consequent low traction and adhesion. The trike would have quickly broadsided out of control. At right angles to the direction of travel the leading back tyre would have caught in any roughness on the road, snow or ice. The trike would have cartwheeled sideways in a flash. With me firmly attached to the pedals spinning arse over tit along with the trike. 

Various parts of my head, body and limbs would contact the ground and surrounding scenery in rapidly repeated succession. Most of my routes have trees lining the road at very close quarters. What would have been my chances of survival on the empty lanes I usually frequent to avoid the traffic on the main roads? I could have lain there critically injured for an hour or more before a solitary "rat runner" or farmer had used the lane. With only two front brakes I remained perfectly safe, on any surface, for a couple of thousand miles of this difficult winter riding. 

Do the brain dead UCI committee of dictatorial rule makers actually ride trikes? Have they ever ridden a trike even once in their lives? Or do they just sit in smoke-filled rooms? Desperately plotting new rules to make cycling much less fun and a bløødy sight more dangerous? (pun intended!)

I'd be prepared to lend them my Higgins to try on a slippery test track just to see how they get on with front brakes alone. Then they can borrow a trike fitted with rear disk brakes and see how they get on with those. On second thoughts perhaps this wouldn't be such a good idea. The lunatics would have all bike and trike riders wearing body armour, knee and elbow pads and full motorcycle helmets with visors before the day was out! With compulsory fire extinguishers, air bags and several flashing beacons on every trike! Just in case...

Note: It seems that others do not have my allergy to rear brakes. Both disks, drums and side-pulls have all been used on trike rear wheels and the owners seem happy to have them. 

Below are a series of images of paired front brakes on standard trikes.  The unusual arrangements are  necessary to avoid conflicts between brake blocks where two brakes are mounted in front of the forks.

My own Higgins with centre-pull brake on hex extension bar in front of cantilevers on brazed-on fork bosses. This was back when I rode on sprints and tubs.

A similar arrangement on Steve's lugless Higgins.
The typical hexagonal brake extension bar is brazed to the fork crown.

Side pull brake on a very long, chromed extension in front of cantilevers on a Longstaff. 
(image found online, source unknown)

A Jack Taylor found in an online image search some time ago.

Interesting, Resilion, clamp-on callipers with a side-pull fitted on a short extension in front. I recognise the cantilevers but can't think where from. It must have been a very long time ago. (eBay auction image) My brother remembers these brakes being popular on tandems and recalled the name a little later. The long brake blocks probably offer superior stopping power.

Side-pull and cantilevers on Alan's beautiful Longstaff.

Twin centre-pulls in a poor image scavenged from eBay.

Centre-pull in front of cantilevers on Jack Taylor on eBay.

My Longstaff conversion with an inverted-cable, twin-pivot, side-pull to the rear of the forks to avoid cable contact with the down tube. A loop of cable/casing ran down beside the fork leg and back up again in a deep U-form. Not a good idea at all. The casing filled with rain and muck and caused friction. The "feel" of the brake was very poor even when first set up and well lubricated. It went rapidly downhill from there.I could easily envisage two cable stops, an a bare section of cable around a pulley (just below) to change cable direction. This would require brazing, of course, but might offer an alternative way of safely applying a cable to the bottom of a suitable, side-pull brake.

Note the ring of damage to the down tube on this recycled frame. The same occurs on the top tube. The bike probably suffered a severe, head-on collision at some time in its life. Which stressed both tubes beyond their elastic limit.  It has now been taken out of action for safety reasons. The entire bike (but not with the trike conversion) only cost me £5. equiv. so it doesn't owe me anything.

Campag side-pull with cantilevers on an immaculate Longstaff.
(Image found online)

Dreirad's superb 1954 Higgins trike restored to as-new condition with a smart LF hub brake and a side-pull on the forks. A neat, all-weather combination. His trike looks as if it has just left the showroom!  I particularly like the crimson paint. Wonderfully evocative of quality cars prior to the cheap, mass-produced models of the 1960s when car paint "went bad".

If anybody else would like to share images of their upright trikes on the blog please do get in touch.

Few brakes lend themselves to a position behind the forks because of their vertical cable entry (or cable pull) of their design.  The cable (or usually parts of the adjustment mechanism) will strike the down tube whenever the handlebars are turned in a particular direction. This leads to cosmetic damage and may even dent the down tube over time. It may strain the metal of the brake itself leading to sudden and catastrophic breakage. It also adds a severe and unwanted limit on turning ability in one direction.

There are now some interesting new brakes coming onto the market. Probably aimed at the low drag demands of the time trialist and the nostalgia wave of the "fixie" enthusiast. With the latter the clean and simple lines of a classical track bike must be made safe and roadworthy. Usually by adding a front brake to go with the compulsory fixed wheel. A freewheel would require two brakes. A rear brake on its own is both dangerous and illegal in many places. Though Denmark has long allowed a single back pedal brake on roadsters. I'm not sure this is still allowed. I shall have to find out.

Good braking is essential to real speed on the road. You must be able to accelerate and ride at any speed of which you are legally capable. Then be able to scrub off the speed safely and rapidly with the brake(s) to take corners while well under control or to slow for obstacles. Poor brakes mean you must hold your speed down all the time in case of corners or potential accidents. This is an incredibly slow way to get about in or on any vehicle. Let alone a pedal driven bike or trike which already has severe limits on it maximum speed because of the human engine and severe wind resistance.

Fixed wheel alone on the road is delayed suicide. Not only does the braking only work on the back wheel but it has not the force to slow you quickly like a proper front brake. Particularly on a trike! On the race track everybody is going the same way. This is certainly not true of the road! Fit really good brakes before worrying about drag or appearance. It will make you much faster. Just ask any racing motorcyclist! Good brakes are worth much more than a few extra horsepower.

A neat brake behind the forks will help to maintain the illusion of a true "no brakes" track bike. These new brake designs pull and push the stirrups simultaneously, but do so directly from the side. So that the cables do not interfere with the frame down tube even when the handlebars are fully turned either way. Handy for when you are doing track stands at the lights! (On a bike) A trike merely becomes a comfy armchair at traffic lights.

What is shocking is that none of the big players has ever produced a brake which could safely hide behind the forks of a normal bike. In fact most manufacturers seemed to go out of their way to make brakes even more difficult to fit there. With foolishly long stirrup extensions and strongly asymmetric designs. Which seemed to have far more to do with appearance than function.

Tektro should be highly commended for their daring in br(e)aking away from the well trodden path of the long established manufacturers. It is rumoured that even more daring designs are due soon. To hide the mechanism right inside specially designed carbon fibre forks on high-end TT bikes.    

The Taiwanese Tektro [R725] and Oval [A700] are examples of the new design. Though they may both be made by the same Taiwanese factory. This illustration shows both names marked on the same brake! Case proved?

The geometry of these new brakes does not look as if it has been fully optimised yet. [IMO] They have taken a basic centre pull brake design. Then adapted the ends of stirrup levers so the cable action is from one side instead of pulling equally from (centrally) above.  There has been no obvious attempt to improve the geometry of the leverage to match this design change. The mechanical advantage is much reduced in comparison with the original centre-pull design. See my drawing above:

In the new design the pivots should ideally be lowered to achieve the same sort of leverage as a centre-pull. Note the considerable reduction in leverage between X and Y:  X:Z  > Y:Z. Only the leverage on one stirrup is shown for clarity but makes no difference to the argument. Since the brake is bolt mounted to the forks conventionally it does not use braze-on bosses. So the stirrup pivots can be moved at will by the designer. By lowering the pivots the ratios of the moment arms would be restored. Perhaps it is unimportant for a brake intended for time trialling on dual carriageways? Though a reserve of powerful braking is always desirable for emergencies. Like all of those moments when a cyclist becomes completely invisible to drivers despite the head to toe, day-glo clothing.

I have read some criticisms of the braking power of these new Tektro brake designs online. Hopefully the braking power is still adequate with the present proportions between force and action. It would be a great shame if this useful design failed through poor adaptation to the side-entry cable arrangement. It has much to commend it if properly designed. Particularly for trikes. Saving us the complication of having to have twin front brakes in front of the forks. This may look quite "techy" but it is still a rather clumsy arrangement.

It is absolutely certain that riders of Time Trial bikes and road going "fixies" will buy vastly more of these "stealth" brakes than those needed to convert the world's entire fleet of upright trikes. Even if you could persuade every trike rider on the planet to do so.

A pair of Tektro R725s, in front of and behind the forks, are shown on the Trykit website.

Here's an image of a neat, Trykit, double, Mini-V-brake set-up. I would imagine this is a very powerful braking system. Again, the cable side entry completely avoids the usual conflicts between cable and downtube. Though at the expense of two more brazed-on bosses. No problem on a hand-built Trykit. Slightly more difficult to copy with bog-standard bicycle forks. I wonder whether Geoff Booker at Trykit would sell a pair of ready-made forks like this?  Thanks to Martin.B for the image.

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