19 Mar 2015

19th March 2015 Technical success and abject failure.

Thursday 19th 32-52F, 0-11C, still and sunny. Stinking of "knock your block off" industrial strength, perfumed pig shit. Lighter winds today but a much cooler start. It might still reach 12C, 54F later if we are lucky.

I was thinking about crank length and how it affects my bottom gear. 160/170 = 0.94. It doesn't sound like much difference but if my bottom gear, using the 160mm cranks is 27", then it effectively becomes 25" gear with 170 cranks relative to the 160mm cranks. It will still be calculated as a 27" gear but the extra leverage obviously helps overcome its potential limitations. I found 175 to be too long for comfort at high revs. It always felt as if my feet were consciously turning in a large circle. With my knees being forced to rotate through a larger angle.

I have ridden most of the local hills now with the new, slightly longer cranks and still find it possible to keep going with a 27" bottom gear. Though I tend to use a slightly lower cadence than when I had a still lower gear available. In fact I rarely used the previous bottom gear 28/30 [25"] because it felt rather too low except on very rare occasions.

It is always interesting to note how fast the pedals turn when I push the trike backwards to park it while in bottom gear. It looks as if the pedals are turning once for every foot or so I travel.  Yet in practice each pedal revolution produces 2.2 metres of development. i.e.it rolls 2.2m/7' per pedal revolution. In real life that translates to 6-7mph in bottom gear with a perfectly reasonable cadence of 80-90 rpm.

Light winds and sunshine? Where shall we go today? I started with a walk. There was still white frost on the grass leading to the more distant woods at 8 am. But the temperature had already reached 48F, 9C by the time I returned with my jacket slung over my shoulder. I was trying to avoid overheating in the bright sunshine and very little detectable wind. Though the turbines were all still turning.

I saw and heard lots of birds including numerous woodpeckers, Yellowhammers and Black caps. Plus all the usual suspects: Blackbirds, sparrows, Great tits, Blue tits, Wood pigeons, Starlings, Rooks and Mallards. A small gang of four Jays were having an incredibly noisy scrap high up in the conifers.

 Athena 11 speed rear dérailleur beside the Ultegra 9 speed. Appearance is very much a matter of taste.

At this time of year, Chaffinches must easily outnumber all the other small birds put together. It is impossible to escape from their rather repetitive phrase and white wing flash wherever I go.While the Great tit is very common but has a remarkable range of calls. Only 7 miles so far. I shall go out again after an early lunch. It is a superbly warm and wind free day now. Even the turbines have stopped after turning strongly earlier on.

My Athena Long Cage 11speed Triple rear dérailleur has turned up. It was still rather early so I chose to fit it on the trike before lunch.

Rather than splitting the new 11sp chain I removed the jockey pulleys individually. Then threaded the chain loop before replacing each pulley in turn with the other in place. The spring tension  is quite considerable and needed great care not to fire each pulley and its loose bearing covers right across the lawn! Note that the Campag pulleys are not the same as each other. With the top pulley being relatively free to tilt. The image alongside shows that the Ultegra and Athena changers are very similar in their proportions. So the Ultegra long cage chain length suited the Athena quite well. Though I have a couple of 11 speed joining links in case I need to adjust chain length if it proves necessary. 

The Athena uses hex socket screws for the pulleys and cable clamp but uses a Torx key for the hinge bolt to fix the changer to the hanger. The more familiar cross-head screws are used for the lateral limit screws and chain tensioner. This last screw acts on a worm and a short arc of a clearly visible, stainless steel wormwheel. The fine teeth of which are just visible in the image below arranged around the pulley cage pivot.

Despite turning the screw right in there is still a little too much clearance between the 32 tooth sprocket and the top pulley. Which is far better than being too close but unable to move it away. The sprocket-pulley clearance had been a slight worry given Campagnolo's insistence on a maximum 29T sprocket. It seems that the Athena Triple rear can probably take a 34T sprocket without problems provided the chain length is a nicely safe, Large/large, plus two links. I have adjusted the indexing until it is as good it gets in its standard form. Now we'll see how it performs out on the road.The gears performed quietly and flawlessly as I rode to Assens and back.

The original Shimano Ultegra chain lubricant seems to attract dirt or is naturally dark in colour. Not an attractive sight in a nearly new purchase!

I was overtaken at high speed in a narrow lane by a sociopathic loser in a faded, old banger. He raised great clouds of brown dust from the mud-plastered road surface as he passed. Forcing me to ride over piles of baked and compacted farmer's soil on the broken edge of the tarmac. I shook my head and this was enough to end his haste to perform emergency brain surgery at some distant hospital. Suddenly his extreme shortage of time was no longer of the least importance. He had all the time in the world!

He pulled up on the verge just ahead and lazily rolled down the window. Demanding to know why I couldn't keep to the side? Apparently I had waved at him last time he passed me. I can't imagine why! His accent was so broad and his articulation so slurred that I really struggled to understand him clearly. There was absolutely no point in getting angry or trying to justify myself. So I remained a passive member of the cycling diplomatic corps as he rambled on.

Finally, he muttered a derogatory Danish term for "foreign workers" and drove off at high speed. Ironic really, considering I am one of the most considerate cyclists on the Danish roads today. Though far from timid, I regularly pull off at the first opportunity. Or, if there is too much oncoming traffic and no handy pull-off, I will sprint on to the next lay-by, drive or junction. Just to allow following buses, lorries, tractors and timid car drivers to pass safely, easily and with the minimum of delay. In fact I have even had two car drivers stop to praise my remarkable thoughtfulness and perfect road positioning to allow easy overtaking.

Click on any image for an enlargement.

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