5 Jan 2016

5th January 2016 The Trykit resurrection.

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Tuesday 5th 25F, -4C, windy but clear. Snow showers possible on top of a strong, easterly wind.

With my replacement levers having arrived and an unfinished Shim[sram]ergo system still incomplete I will have to get busy. It is still very cold and won't be any warmer the shed. The wind is still gusting to 12m/s or over 25mph so wind chill at -4C puts is near -20C equivalent.

I always prefer to work outside with the trike up on the workstand. There is not enough room in the shed to work all around a trike.

The image shows the pulleys now pivoted at the 2nd [output] pulley. The dimensions shown provide a perfect match of 1:1.38 between the Ergo 11 speed levers and the XT11 MTB rear derailleur.

Even with the cable clamps on the swinging arm the indexing was perfect. The Ergo lever movements had been lighter than with a Campagnolo Athena 11 speed rear changer. Tragically my lack of maintenance and constant gear changing had caused the right hand Chorus lever to give up. I believe a small pawl had broken off. One which usually pushes the ratchet wheels around to select gears by gathering and releasing cable in indexed steps. I have not attempted to dismantle the broken lever despite there being excellent videos online. Fortunately I was able to ride my back-up Higgins trike or I would have been without transport.

In the meantime, I have been "thinking furiously" about how to overcome the sharp cable bends I was forced to use with the original cable clamps. These damaged the cable and made it impossible to withdraw the inner from the final RD loop. It was far too crude a system for my tastes. So now I am hoping the rubber "pulleys" will solve the cable problems by providing enough friction to avoid cable slippage. Hopefully without any need for cable clamping at all. If the cable does slip then I shall have to add a non-damaging clamp to the swinging arm. Since the cable will pass straight through the clamp there will be only a little cable flexing at the anchor.

The pulleys are thinner than the original clamp bolt heads. So the pull-ratio changing mechanism is narrowed quite considerably. It could be made thinner still by cutting a single piece of aluminium to support the asymmetrically arranged pulleys. The disadvantage is that adjustability is lost unless I slot the pulley fixing holes. Otherwise the geometry would have to be designed for a specific match between a chosen lever and a particular rear derailleur. I have no need of adjustability myself because my choices are already made. Though it is nice to have some leeway should it be needed in practice. It is quite possible that the swinging arm geometry will affect the cable pull per click at the extremes of arm movement. This could be compensated for by slightly altering the relative positions of the pulleys. If the indexing runs short of movement on the lowest gears then the ratio could be slightly increased.

The rubber pulleys proved to be too soft in practice. They offered plenty of cable grip with good indexing but the cable was soon dragged over the grommet's rim sideways by the offset cable pull. The only way to get a straight pull would be to drill holes right through the seat tube down by the bottom bracket. You may rest assured that my near-obsessive desire to have the Shimergo system working does not extend to that level.  I have gone back to using the original cable clamps for the moment despite the sharp bends. This problem could be overcome by using turned alloy pulleys with deep rim grooves. In the image it looks as if I have reversed the pivot clamp but it makes little real difference.

There is a serious problem with the rear derailleur cable loop being blocked by the trike's rear axle loop. After much fiddling I was able to find a point where rotating the "Direct link" allowed the cable to reach the changer. It was just bad luck that Shimano had made the cable entry at such an extreme outward angle to the vertical. How this would affect an MTB is difficult to say but it must surely make the rear cable loop extremely vulnerable to catching on branches. A mere 1/4" shorter "Direct link" would have helped the cable to clear the axle loop completely. The XT11 changer wouldn't fit directly on the Trykit gear hanger without the supplied link.

It took ages to get the tape off the handlebars where it had welded itself to the silicone shock absorbing strips. The black finished bars have suffered considerable cosmetic damage where I had the tri/bar extensions clamped. I may have to tape the bars right to the center. After weak morning sunshine it clouded over, as if about to snow, but hasn't so far. It didn't feel too cold in my big duvet jacket as it slowly warmed up to -1C, 30F.

I had to go back to the thinner central spacer on the Trykit 2WD because the freewheeling friction was far too high with the original spacer. It was very hard work turning the pedals in top gear even without the back wheels because there was so much drag! It is much better now with the thin spacer in place. I just have to re-tape the bars now and I will be mobile again.

Click on any image for an enlargement.
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4 Jan 2016

4th January 2016 Swinging arm design completed.

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Monday 4th 23-29F, -5--2C, gales and feeling bitterly cold again. The wind is supposed to drop from gusts averaging 17m/s, 38mph to a "balmy" 15m/s or 33mph. With these winds and the low air temperatures the wind chill factor makes it very unpleasant indeed being out of doors. Just handling any metal in the unheated shed is painful. Heating the uninsulated shed, just so I could work out there, would result in massive condensation and rust on unprotected metal. Besides, it would take ages for tools and metal to reach comfortable handling temperatures. The replacement Campag levers, which I originally ordered on the 15th December from Wiggle, have finally reached Billund sorting center in Jylland. Expected delivery is still listed as "by end of today on the 4th" but it hasn't been marked as "out on the van for delivery" yet. Only as being the hands of the delivery agent.

The trick when it is only 28F in the shed to avoid one's nose dripping on the item being worked on. I botched together a quick arrangement of two [grommet] pulleys on a scrap alloy crossbar. Only to discover I should have been more generous with the spacing to allow the pulleys to clear the central, crossbar fixing screw. Still, it will take only a few minutes work to put something better together.  I also want the pulleys flat on their crossbar to reduce the depth to something which would fit behind a chainset to make it more universal. Having the pulleys pressing on the crossbar would also reduce the risk of their rotating.

The plan after lunch, when my feet have warmed up again, is to to make a longer pulley-supporting crossbar. This will correct a number of interference problems which cropped up with the first trial construction.

Another thing which I hadn't foreseen was the limited range of ratios available from a given arrangement of two pulleys on a pivoted arm. I had fondly imagined that by simply rotating the crossbar I'd achieve a whole range of desirable pull ratio changes. It wasn't to be. Measuring with a vernier caliper, with the narrow jaws sunk into each pulley groove in turn, resulted in some odd ratios. This is the result of two equal sized pulleys, equally spaced from the central pivot. A more asymmetric layout will help to break the lock-step in ratios.

On the left is the new version of the swinging arm with this morning's problem's corrected. The 74mm measurement is simply a suggestion which fits my own trike. The pulleys are now fixed flat and immovably on the adjustable crosspiece. With the 1st pulley bolt now acting as the ratio adjustment pivot for the crosspiece. The Ist pulley is now fixed as to its radius from the swinging arm pivot. [74mm] The 2nd pulley is bolted to the other end of the crosspiece to allow only a little clearance between the two pulleys. [To maximize cable wrap for more friction.]

Rotation of the crosspiece will lift and lower the 2nd pulley relative to the 1st pulley and the swinging arm's own [top] pivot. This movement will set the output pull-per-click ratio to match that desired. Then the 1st pulley bolt can be tightened to lock the 2nd pulley and crosspiece at precisely the chosen, cable pull ratio. The pulleys are merely a convenience to protect the cable from sharp kinks and fraying. While simultaneously providing considerable friction against the cable slipping against the grooved rims.

It might be worth sandwiching a thin, but large diameter, star type, lock washer between the crosspiece and the swinging arm to avoid any chance of the crosspiece ever working loose. Stainless steel screws and SS Nyloc nuts will be used throughout. The swinging arm can probably be trimmed in width for cosmetic purposes.Or neatly chain drilled if you want a "techy" lightweight look. My own swinging arm is just a strip of scrap aluminium sawn from a larger piece. It is very soft but will take a tapped thread if some extra degree of locking is desired.

In my case the bottom of the 1st pulley rim groove [measured at the top of the pulley] is fixed at 74mm from the center of the swinging arm pivot hole. This figure is multiplied by the desired ratio change to match the gear lever to the rear changer. I needed an increase of 1:1.38 to match my Ergo lever's cable pull, per click, to an XT11 MTB rear changer. After  multiplying the Ist pulley [rim] radius of 74mm x 1.38  I then rotate the crosspiece until I can measure 102mm. This measurement is from the swinging arm's top pivot center to the bottom of the 2nd pulley groove on the right. The red line shows the required cable wrap which is deigned to maximize friction of the cable against the rubber pulleys with horizontal input and output cable runs. Any cable slippage would undo the cable pull-ratio setting. If I did discover cable slippage I could easily add a non-damaging cable clamp bolted through a slight elongation of the present arm length. Or I could move the 1st pulley pivot hole upwards slightly to make room for a cable clamp, screw hole on the end of the swinging arm.

The downtube gear cable enters from the right to join the top of the 1st pulley. The cable is then wrapped as shown so that the output from the second pulley runs along below the chainstay from the bottom of the 2nd pulley. Until the cable meets the cable stop for the rear derailleur, outer cable. 

With this simple lever system you can run any rear derailleur with any handlebar lever. Whether the cable pull ratio needs to be increased or decreased on the way makes no difference. The crosspiece is simply rotated until the desired ratio change is achieved on the output end of the cable to match the needs of the RD. It is assumed that the gear lever lets out [and takes in] equal lengths of cable with each click. Some Campag levers alter the pull per click and even have different spacers between different cassette sprockets.

This latest iteration of the swinging arm is probably thin enough overall to go behind a chainset on a bike. With the arm pivot on a clamp just below the FD. There being no room behind the bottom bracket on most bikes a trike has masses of unused room back there. If the 2nd pulley gets in the way of the FD then the the crosspiece pivot could move to the 2nd pulley. With the 1st pulley now fixed on the far left of the crosspiece. There's probably not much more than $1.50 or £1's worth of material and half an hour of [almost] tool-free construction in the entire arm. The Shimano FD clamp, from which the arm is hung, might run to a £enner if you don't have one already. Or can't scrounge a secondhand one from your LBS as I did. 

The "pulleys" are blind rubber grommets designed for sealing a 20mm hole in a thin metal box. Usually where mains electricity is present but not intended for domestic use. The grommets are drilled through their blank centers and a washer [or washers] added to a 5mm center, fixing screw to stiffen the grooved grommet rim against being pulled out of shape by gear cable tension. 

Those with an experimental bent can try making pulleys from different sized grommets to match what is available. Provided you achieve the correct pull ratio the design can be shrunk slightly. The smaller the pulleys the tighter the cable must bend around the pulleys. Perhaps with an increased risk of cable fraying. A shorter swinging arm may introduce cable pull errors at the extreme ends of its arc. Do a full scale drawing and examine how smaller swinging arm radii affect the pull per click on horizontal entry and exit cable runs. Don't forget to allow for the full cable movement at the rear gear changer [RD] when you draw the full arm swing both ways. In my case it is 36mm.  

 If I did turn up some alloy pulley inserts in the lathe, instead of the present washers, I'd need to remember to countersink the screw heads.There is no need to use pan-head screws when stainless steel CSK screws would do a much better job on turned alloy inserts.

My replacement 11 speed Campag Chorus Ultrashift levers have finally arrived. I can now set up the gear system and test for indexing with the XT11 8000 MTB RD. Only 7 miles today into a freezing headwind on the first leg. The tightly knitted balaclava I wore was not very windproof but helped to protect my cheeks. I will wear a GripGrab scull cap underneath next time I need a balaclava on the trike. I must also search for skiing goggles with lighter lenses. My eyes were watering on and off into the headwind despite wearing wrap-around cycling sunglasses. I bought a pair of skiing sunglasses with frame edge seals online but they are so dark they are hopeless in anything but high altitude alpine sunshine on snow! My visit to a skiing shop in the city did not turn up anything with lighter lenses in skiing eye-wear.

Click on any image for an enlargement.

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3 Jan 2016

3rd January 2016 The C-word!

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Sunday 3rd 23F, -5C, roaring gales to 17m/s or 35mph. The promise is for some sunshine but the low temperature and wind speed will make it feel very cold. The wind chill factor is somewhere around -25C in 35mph gusts according to The Danish Meteorological Institute's Kuldeindeks chart for 18m/s @ -5C. There is not remotely universal agreement between wind chill charts posted online. Not even when the same units are used! The windchill factor relates to what it feels like. The problem with wind is that it can breach the heaviest insulation and poorly windproof clothing unless a totally windproof shell is worn. Which is rarely a good idea if man-made materials and serious exercise is involved. Windproof often means it acts as a barrier to moisture escape.

I can clearly remember my first winters on the trike when I still wore [sometimes multiple] fleece jackets and supermarket "skiing" gloves "for warmth." On descents my chest would get colder and colder as my speed increased. Until it felt as if the wind was passing right through me and out the back! It was only later that I would routinely search charity shops [near and far] for "proper" cycling jackets. I was lucky and found several and still use each of them according to the temperature and wind conditions. 

Each jacket has its own, surprisingly narrow, temperature range within which I will [hopefully] avoid sweating or freezing. The main problem is usually finding myself overdressed when climbing. Opening the front zip is no guarantee of a cool back. That prickly feeling is soon followed by that sickening cold as the sweat chills on the next descent. Denmark is heavily corrugated without achieving any real altitude. Climbs and descents come as regular as clockwork on many of my usual routes. I see the "weekend warriors" on their "plastic fantastic" machines looking almost naked in their ultra-lightweight winter clothing. Always in black of course. While I cheerfully pedal the lanes in bulky "coat of may colours" cycling jackets from yesteryear.

I have discovered how very narrow a range of temperatures my jackets offer comfort. So I would be terrified of spending serious money on a single, black, skintight, winter jacket and matching long tights. Just so that I too, can look half naked in a gale and simultaneous frost. Perhaps it is most telling that I often find myself the only cyclist I see on the roads in winter. [Apart from hardy Danish pensioners out shopping.] Which might suggest that the level of protection offered by these long, black condoms is as marginal as they are visually discreet. Having once ventured forth in tights sans shorts I can attest to the feeling of serious under-dressing for a quiet ramble in the supermarket aisles. Were I to don the black suit look I might also have to wear a red nose to confirm my status as the local clown.[on a tricycle]

There used to be mime arteests on British TV who would wear black skin-tight clothing by default. I might be tempted to start seriously misbehaving beside the freezer cabinets, in my new, skintight outfit,. Which might result in my refugee status [from the Margaret Thatcher regime] being rescinded. Being forcibly repatriated to Gravely Blighted would probably be too much to bare. [sic] Particularly after all these years of riding on the "wrong" side of the road. I would certainly have to swap my Cyclop rear view mirror to the other handlebar end. Then sign up for an intensive course of evening classes, on the British Highway Code, simply in order to survive. It is bad enough glancing [all too frequently] down at a non-existent mirror when I am walking beside the road!

So I would probably have to seek sanctuary in a foreign embassy. Anything to avoid the ignominy of a return to a British Airport in full public view of the waiting press. Not to mention the throngs of admirers thinking I was a homecoming [winterized] Sir Bradley Wiggins. Besides, I am fairly sure that two trikes are not their idea of walk-on, hand luggage. Not even if I did have the assistance of two MI5/CIA security officers to help me down the aircraft steps. They might get fed up with my rambling demands and send me on extended holiday to Cuba!

Six years later I am still struggling to find gloves with any pretensions to warmth without getting sweaty hands. I have tried GripGrab's overpriced assortment, with only marginal success, dangerously crap Sealskinz and bulky, Dintex scooter gloves. One pair of Dintex scooter gloves sweats badly and then freezes my hands. The other pair do not. I presume they changed the membrane for something cheaper somewhere along the production run. So sometimes I get aching hands from frostbite but I can't tell the gloves apart. So frozen moisture is the norm at least 50% of the time.

Normally I wear carefully selected, thin "skiing" long johns and tights [bought cheaply from supermarkets] all autumn, winter and spring. Though I cling onto my naked knees for as long as possible and return to hirsute freedom as soon it warms up again. The stretchy material is too thin to absorb much moisture but helps to keep me dry and warm. Thereby avoiding intimate contact between my moist skin and my middle clothing. Over the ski vest I always wear one of my extensive collection of [secondhand] short-sleeved "racing" jerseys. All bought from charity shops of course. I always wear padded racing shorts too, for their comfort and protection from saddle sores. My regular rides may not always be very long but their frequency demands that I avoid getting sore. Otherwise even contemplating greater distances becomes impossible. 

I spent three years wearing poor quality shorts and poorer saddles. So I know exactly what it felt like to be in constant pain every time I sat down. Including sitting on two soft cushions on my already  comfortable computer chair. Saddle soreness always set my maximum distances and I took far too long to discover the Brooks B17.

I kept trying different saddles including a seriously painful and overlong relationship with the NOS Brooks "Professional." I kept wanting it to work for me but it rejected every attempt to make it comfortable.  I had previously bought a B17 'Narrow' when the LBS had no standard B17s and I found that too was painful. My pelvic bones structure insists I need a wider seat and one which is preferably, both reasonably compliant and almost flat. Curvature just tends to act as a wedge between my sit bones. The compliance need not necessarily mean softness. Certainly not a thick sponge cushion under a vinyl top.  

Now I like the better models of the "proper" B17 for their width, superior leather and larger rivets. Though the cosmetically gorgeous "Select" was rather too soft and went banana-shaped sideways. I now favour the B17 "Special" with its copper rivets and thicker leather than the black Bog17 Standard with its tiny, rust-prone, iron rivets which pull through the leather in old age. Even so, the "Special" has to be [neatly] laced to avoid premature sagging. A decent pair of leather-punch pliers works wonders here. Those who would take an electric drill to a decent leather saddle have probably enjoyed far too many "slasher" horror films!

The C-word C17 purchase was a dreadful and expensive mistake! Like all my saddle purchases I was taken in by the lies hype but still desperately wanted it to work for me. The C-word was all hype and offered no comfort at all! Far too curved across the back, as hard as rocks and hideously unforgiving. It even grabbed my shorts and rucked them up. So any hope of lasting comfort on a ride was quickly lost. They claimed it was a B17 equivalent without needing breaking in, tensioning or even a rain cover. It was claimed that the "organic virgin Vegan" C17 could be ridden in perfect comfort straight out of the over-packaged box. They quite literally lied through their teeth and nobody will ever make me believe otherwise!  [Modesty forbids me to show any images of the C-word here which might accidentally result in any cyclists salivating over a potentially disastrous purchase. You can never tell with cyclists whether they actually read the text or just drool over the pictures.]  
The Selle[r] hype department obviously lead the charge by refusing [flatly] to have a flat, comfortable bench for the distance rider, on which to rest their Ischial tuberosities. This destroyed all chance of material flex over the vital sit-bone support area. The rails are as stiff as the rock-hard rubber is. All thanks to the rigid fiberglass patch desperately added as an afterthought [to ensure life-long longevity] did not result in a class action from the ambulance chasers. My own opinion is that the "chancers" will be flogging these C-word saddles as "hardly [sic] used" for decades to come on eBay. So literally nobody will ever test the C-word's true longevity.

If only a serious cyclist had been involved in its design instead of leaving everything to the Ferrari-driving, Seller advertising director's tart mistress. They even tried to modify her broken design by cutting a huge hole in the top. Which only made it look like a hideous prosthetic for the chronically incontinent. Crossed with a very nasty, medieval, sex toy for those who like a nice bit of S&M! The factory desperately wanted "go faster" and "weekend warrior" looks to overcome potential sales resistance to a wider, flatter, touring saddle. [i.e. Something just like the real B17!]

They certainly got the curvy looks.  It is really is quite a pretty saddle if you like that sort of thing. With some nice details too if you ignore the dreadnought class weight, undersized girth and obvious fraying around the rivets. A touring saddle it is most definitely not! I'm thinking more like 250lb+ American riders who obsess about mere grams on the "weight weeny" cycling forums. Ideal for those "serious riders" who have been looking for a new saddle for their fixy. One which won't get irrevocably lost between their nuclear submarine sized buttocks on that short, Saturday morning ride to the local McLardy's Club meet to get "Macxed out."

Perhaps Selle[r] should have talked to somebody at Brooks instead of keeping the C-word completely in-house down in balmy Italy? Could the rubber possibly soften up after baking for an hour [or three] in the Mediterranean midday sun outside a rural, Italian, roadside, mountain café? The saddle gently cooked as the poor Selle[r] saddle testers rested their tender regions on hemorrhoid cushions after a few short but painful kilometers. ie. Until safely out of sight of the factory! With so much invested in its potential sales the Selle[r] testers couldn't possibly be whistle blowers could they? Guess what? They weren't!

I bet they spent far more time, expense and effort at the Selle[r] factory designing the packaging than they ever did on the "comfortable out of the box" saddle. Of course, there is a very slim chance that it has all been a hideous mistake due to a break down in communications. The Selle[r] Unadulterated Hype Director was looking down from his glazed, ivory tower one day and intimated to a passing serf that he wanted a new saddle. One which could be taken straight out of the box and be as comfortable as a just-broken-in B17.

The garbled message, was duly filtered down through several ranks of constantly genuflecting and back-stabbing, under-managers. To eventually reach the ever-so-humble minions, in the dank and dingy R&D Dept. in the cloud castle dungeons. By which time the message had lost something in the translation.

"Real" saddle design is all done in the "Arts and Hype" Dept. upstairs. Where physical testing is completely unnecessary thanks to a few, carefully posed iRottenApple computers strategically placed for maximum decor value for visiting cyclo journo clebs to admire. Why else do they wear vintage cycling jerseys with capacious rear pockets if not to take their [money laundering] bribes home in unmarked notes?  The Word from On High had [apparently] pronounced that the splendid new C-word should be: "Just like a B17 taken straight out of the box." And so it was! ;-))   [Modesty forbids me to show any images of the C-word here which might accidentally result in any cyclists salivating over a potentially disastrous purchase. You can never tell with cyclists whether they actually read the text or just drool over the pictures.]  

Even wearing thin tights adds seams where seams are best avoided on/under a cyclist. I've tried warmer cycling trousers but always overheat even in a hard frost.  Most "civvy" clothing is put together with thick seams coming to a hard knot right in the middle of the crutch. It can take quite some searching to find affordable, non-cycling underclothes with flat seams. Bibs came late to my clothing collection but are superbly comfortable on longer rides. I hate spending money on cycle clothing but good shorts and better bibs are absolute essentials. [Along with real saddles!]

The DHB shorts are okay for daily use up to [say] 40 miles though I have ridden further in them. The Tactic bibs go on if I plan on anything over 50 miles. It just isn't worth the risk of wearing shorts. Simply because they do not conform as well without the vital, but gentle tension, of the soft braces on bibs. I have spent far too many miles standing up at every opportunity. Often every few yards towards the end [sic] as I suffered endlessly from saddle soreness.

My footwear choice after several year's hiccups, is now North Wave MTB with SPD cleats. But only because NorthWave offer greater width for my size EU 46.2525 pedantry plates of meat. The NW shoes have proven to be, not only [rapidly] cosmetically challenged, but able to break their own buckle springs within 2 years from new. It is now many months since my dealer offered to try and get me a single £20 + P&P strap and buckle replaced under guarantee. I had flatly refused to pay for it nor pay so much.

Needless to say he will not be enjoying my custom when I seek replacement cycling shoes. Probably this year as it warms up because I now have no functioning summer shoes for want of a single North Wave buckle spring. Toe-clips and straps are not sensible on a trike due to the lowered bottom bracket. It is all too use to "dig in" a toe-clip even on normal camber. Escaping from toe-clips and straps may not have the emergency quality of riding a (cough) bicycle but ought to be easy if rider longevity is desired. 

Meanwhile, the NorthWave MTB winter boots have been fine and have saved my feet from painful winter chill and wet. Though they do look absolutely appalling because they collect and display every single drop of mud from road spray. Just the price of running 25mm tyres on tight clearance forks. Though I may be able to remedy this awkward situation after being 'improved' by my brother.

Click on any image for an enlargement.

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