Author Topic: Rohloff sprocket wear  (Read 1725 times)

Andre Jute

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Re: Rohloff sprocket wear
« Reply #45 on: April 28, 2019, 06:40:51 AM »
Last night at dinner I mentioned a Polish pianist (whose name I'd forgotten; it happens: I'm terrible on names) of whom I wrote that he performed surgical operations on the keys. He went to the trouble of making three calls (to the newspaper he read it in, to my syndication service, to my agent) to get my number, then called me and said, "Professionally, I'd rather have the hands of a butcher, a huge spread of fingers." Three decades later I was sitting in a country house library, with several professional pianists also appearing at the same festival, and when Marc-Andre Hamelin -- this was before he was famous, so I'd never seen him in the flesh -- sat down at the piano and stretched his hands prior to playing, I was startled into saying, "Behold, the hands of a butcher!" The pianists looked at me rather oddly...

Mind your fingers in the spokes or you'll need Bach's 38 (homeopathic remedies extracted from flowers by Dr Edward Bach).

mickeg

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Re: Rohloff sprocket wear
« Reply #46 on: April 28, 2019, 02:53:58 PM »
Last night at dinner I mentioned a Polish pianist (whose name I'd forgotten; it happens: I'm terrible on names) of whom I wrote that he performed surgical operations on the keys. He went to the trouble of making three calls (to the newspaper he read it in, to my syndication service, to my agent) to get my number, then called me and said, "Professionally, I'd rather have the hands of a butcher, a huge spread of fingers." Three decades later I was sitting in a country house library, with several professional pianists also appearing at the same festival, and when Marc-Andre Hamelin -- this was before he was famous, so I'd never seen him in the flesh -- sat down at the piano and stretched his hands prior to playing, I was startled into saying, "Behold, the hands of a butcher!" The pianists looked at me rather oddly...

Mind your fingers in the spokes or you'll need Bach's 38 (homeopathic remedies extracted from flowers by Dr Edward Bach).

I worked in a grocery store part time when I was in high school.  I was rather surprised to see that many if not most butchers had at least one digit that was shorter than it previously had been.

Andre Jute

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Re: Rohloff sprocket wear
« Reply #47 on: April 28, 2019, 11:18:16 PM »
Gruesome. I could never embark on a life of crime: as a young adult I used to spend some college holidays going to fight for the freedom of our black brothers. Up in the Congo, the Colonel and I were lying behind a log while Cuban commies shot at the woodworm, swapping lines from Greek plays (I'd first met him when at 16 I was offered a cruise in the Med on his sailboat for helping him with his translation of Homer). At one dramatic point of declamation I got carried away and gesticulated with a hand in the air above the log, and a bullet just tipped my forefinger, which to this day has a small but distinctive score across the fingerprint whorls.

I must still wipe down the spokes on my bike, which I leave to last, sitting on a stool beside the bike, because wiping the spokes gives you a chance to inspect all the most critical parts of the bike. Actually I also use the stool for the next part of the annual wipe-down service (the washdown this year was special, for the bike's tenth anniversary) which is to check all the nuts are correctly torqued. You don't really need to look at the nut because the torque wrench makes an audible click but if there's anything wrong around the nut somewhere, you'll see it only by focussing on that small part of the bike.

A curiosity. The ESGE Pletscher stand on this bike is attached to a solid tab on the internally and externally strengthened and multi-braced lefthand chain stay. On top, visible, it has the hex socket heads of nice stainless bolts, but turning them causes nothing but a disaster. What the bolts actually do is hold on a half-round piece of metal, flat on one side, to a hollow channel on the mounting surface. It looks like the thing was designed to be bolted directly to a round chain stay with threaded inserts in it. Such a perforated chain stay would be the sort of incompetent, dicey design that would cause Andy Blance at least to curse (hey, a guy from the Porsche factory who was very impressed with the handling of my car when I took him around the track, when the car was up on the hoist so he could inspect the track control arms I had bent up from soft ali on a Black & Decker Workman -- on seeing what he'd trusted his life to fainted dead away, but he just didn't know what was fast: I put 10K racing miles on those ali bend-ups before they cracked badly enough to put your thumbnail into). The threads of the two bolts pull up the adapting filler/spacer in the hollow, then extend beyond the assembly. The bolt extensions are put through the plain holes in the thick flatmounting tab brazed to the chain stay, and then fixed with washers, spring washers and a nut on the back. So all you do by turning the obvious hex heads on the outside of the bike is break the half-round spacer free of its brazing and then strip or break the bolts; instead you need to turn the nuts at the back. Since on a Rohloff bike with sliders, and an EXT fitting right there as well, actually under the tab and blocking the view of the nuts, there is so much going on in that area of the bike that I suffered hours of frustration before I brought the stool and sat down determinedly to inspect what the hell was going on. This, by the way, isn't the sort of thing you expect to find explicated in the manual of a baukast fahrrad (roughly, a German custom bike) because in essence you can order any fitting you want as long as the vendor doesn't consider it inferior, and anyway you're supposed to return the bike to a dealer near you every year for a service to maintain your ten-year guarantee, and the dealer will have been trained at the factory that the bolts on this particular stand are not turned from the front... You guys with Thorn bikes and on this forum just don't know how lucky you are to have so much hard-earned expertise so close to hand.
« Last Edit: April 28, 2019, 11:26:15 PM by Andre Jute »

Prince of Darkness

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Re: Rohloff sprocket wear
« Reply #48 on: April 29, 2019, 10:24:08 AM »
I always remember seeing a documentary about Jazz Guitarist Tal Farlow. He had truly massive hands!

Although not a Butcher, I do appear to have one finger on my right hand noticeably shorter than it's left equivalent. The fingers are actually the same length, but I broke a bone in my hand playing Rugby many years ago and the knuckle is now slightly lower down.

julio

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Re: Rohloff sprocket wear
« Reply #49 on: May 09, 2019, 07:08:25 PM »
I show you my Surly chainring after 15000 kms, it traveled mountains, dust and sand but i don't think it appears tired..


geocycle

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Re: Rohloff sprocket wear
« Reply #50 on: May 09, 2019, 07:41:22 PM »
Looks in very good condition given what you have put it through. Mine is much worse at the moment, done a lot of miles but the teeth are nearly pointed. I plan to replace it and the chain soon. I hope to get away with reversing the sprocket as itís not gone as far as the chainring.
 

Andre Jute

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Re: Rohloff sprocket wear
« Reply #51 on: May 09, 2019, 10:09:10 PM »
I show you my Surly chainring after 15000 kms, it traveled mountains, dust and sand but i don't think it appears tired..

Looks like there's quite a few thousand miles left in it.

John Saxby

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Re: Rohloff sprocket wear
« Reply #52 on: May 10, 2019, 01:26:35 AM »
You've had good luck with your Surly ring, Julio--I hope it continues to give you good service.

In July 2018 I replaced my 36T Surly ring, which had about 10,000 kms on it.  The teeth were not too badly worn--you could see some wear on the "lower slopes" of each tooth, at the front side--but the ring itself had become ovalised, and that was stressing my chain.

I bought my old 36T ring in June 2015 in New York City.  The guy in the bike shop (on 10th Avenue in Manhattan, in the 40's) said that Surly's stainless rings were durable, but that in his experience, the quality varied from batch to batch. He said it was not uncommon, for example, to find a batch in which the rings were slightly oval.

Looks like you have one from a good batch!

Safe journeys, glad your squeak decided that it was pointless making a fuss, and gave up :)

John

geocycle

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Re: Rohloff sprocket wear
« Reply #53 on: May 10, 2019, 09:08:56 AM »
You've had good luck with your Surly ring, Julio--I hope it continues to give you good service.
The guy in the bike shop (on 10th Avenue in Manhattan, in the 40's) said that Surly's stainless rings were durable, but that in his experience, the quality varied from batch to batch. He said it was not uncommon, for example, to find a batch in which the rings were slightly oval.


Agreed. I have a Surly ring I've never been able to get properly centred causing a tight spot on the chain.  Never had a problem with the Thorn rings where the recessed bolt holes also help with alignment.