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Path: ...!3.eu.feeder.erje.net!feeder.erje.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Frank Krygowski <frkrygow@sbcglobal.net> Newsgroups: rec.bicycles.tech Subject: Re: Fine Tuning Shifting Date: Wed, 14 Aug 2024 20:25:28 -0400 Organization: A noiseless patient Spider Lines: 116 Message-ID: <v9jhtp$lbsl$3@dont-email.me> References: <18yoO.17738$iptd.15227@fx36.iad> <jkvnbjl7ierhe6r0nqg0em72e4p9keo38v@4ax.com> <zy8vO.109367$x8Nb.98698@fx06.iad> <v9j69l$jnm5$1@dont-email.me> Reply-To: frkrygow@gmail.com MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Thu, 15 Aug 2024 02:25:29 +0200 (CEST) Injection-Info: dont-email.me; posting-host="ca765edf75df101b37580ba443efd965"; logging-data="700309"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+bSk3sMsb86Gg1m+CGENuoyURGGuTCHCw=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:Ji3sQiRh6VLnl0QH8a1gmu1siiE= Content-Language: en-US In-Reply-To: <v9j69l$jnm5$1@dont-email.me> Bytes: 6777 On 8/14/2024 5:07 PM, AMuzi wrote: > On 8/14/2024 3:35 PM, cyclintom wrote: >> On Tue Aug 13 17:47:38 2024 Jeff Liebermann wrote: >>> On Thu, 25 Jul 2024 19:58:53 GMT, Tom Kunich <cyclintom@yahoo.com> >>> wrote: >>> >>>> I have a continuing problem with the shifting goin out of adustment. >>>> In one case the right shifter wire partially broke from my over- >>>> tightening it but in the other three cases I've had to mark it down >>>> to cable stretch which Andrew says doesn't exist. But the wires did >>>> not move and the shifting moved towards shifting into a faster gear. >>>> I can only assume that wire layup tightened up a little and showing >>>> those symptom.> >>> >>> 1.2mm galvanized cable (shifter cable): >>> 120 kg (265 lbs) min breaking load. >>> >>> 1.6mm galvanized cable (brake cable): >>> 220kg (485 lbs ) min breaking load. >>> >>> <https://en.wikipedia.org/wiki/Working_load_limit> >>> I don't know the safety factor, but my guess(tm) is about 5 for the >>> brakes. That puts the maximum load for the brake cable at: >>> 485 lb / 5 = 97 lbs >>> >>> I don't know what you're using for a shifter or brake level. The >>> mechanical advantage can't be much. This covers brake lever >>> mechanical advantage, but not shifter: >>> <https://www.toolonpyora.fi/post/mysteries-of-the-cantilever-brake- >>> what-about-the-brake-levers> >>> For brakes, my guess is no more than 37 lbs with a mechanical >>> advantage of about 6. Therefore, with a strong grip, you might be >>> able to tension the cable to: >>> 6 * 37 lbs = 222 lbs >>> >>> We lose grip strenth as we get older. For 65+, the typical RH grip >>> strength is more like 21 lbs >>> <https://godsofgrip.com/pages/average-hand-grip-strength> >>> 6 * 21 lbs = 126 lbs >>> >>> The shifters will be very different numbers, but I don't have enough >>> info handy to work those out. >>> >>> Pulling on the brake cable with 126 - 222 lbs is more than the 97 lbs >>> required for the minimum breaking load. >>> >>> <https://testbook.com/physics/stress-strain-curve> >>> -- >>> Jeff Liebermann jeffl@cruzio.com >>> PO Box 272 http://www.LearnByDestroying.com >>> Ben Lomond CA 95005-0272 >>> Skype: JeffLiebermann AE6KS 831-336-2558 >> >> >> >> >> What does galvanized wire have to do with anything? Campagnolo uses >> finer wire twisted more turns per inch. Shimano inners use thicker >> individual wires with fewer turns. You know note of this and make >> comments that have nothing whatsoever to do with it becayse you don't >> know anything about bicycles. >> >> Shimano derailleurs have a higher spring tension and Campy has lower >> spring tension. So if you use Campy wires on a Shimano setup it will >> pull the wires tighter. >> >> Andrew apparently missed this fact and that he was talking about >> crappy setup which you might consider correct IF you're using one >> Campy wires on Shimno. This was my problem with three or four >> adjustments to reach equilibrium. This was continually commented on by >> Krygowsky because he is a freewheel friction shifter who CANNOT HAVE >> THAT PROBLEM. But he can comment on things he knows nothing about. >> Sort of like Liebermann. >> >> I am willing to believe that Flunky raced friction shifters but that >> his memory of that is so poor that he doesn't even remember how he did >> it. On the beginning of a YouTube video (about a race Lemond won) >> there was a HEADER showing a freewheel frcition setup going through >> the gears and there was perfectly distinct pauses between gears as the >> power was shut down. What was also distinct about that video was that >> racers did NOT follow as closely as they do now because of that large >> variation in power causing accelerations to be rather spotty. >> >> I have had it with stupid asses that know nothing about the subject >> shooting their mouths off about it. Liebermann is the most coommon >> contributor to stupidity. Krygowski is easily the second. No other >> person in the world would pretend that it is stupid to wonder what >> meansurement system that Torx fittings are designed under. Krygowski >> is too dumb to know that you cannot have a standard without >> measuremnents. Questioning if those standards are English or Metric or >> either is beyond his ability to think. >> >> Flunky just talks ahbout crap that he doesn't know about. Notice how >> he could not answer how you measure the length of a wire >> electronically? That's because he personally doesn't know how to use >> an oscilloscope. Which comes as no > > We do not see any functional difference between Campagnolo and Shimano > brand gear wires (used in the appropriate lever of course). We also use > Campagnolo tandem (3 meters) gear wires on XL road bikes with Shimano > equipment without any foibles or failures. > > In fact, gear wires in modern road systems with correct casing, ferrules > and setup are notably reliable. The failures are nearly all at the > lever, where the wire wraps on its capstan. This is not an issue with > flat-bar levers BTW. I'd like to take this moment to note that Tom is claiming that Andrew, Jeff, Funky and I are all mistaken on this (and almost every other!) point. Yet somehow, it's _Tom_ that is continually narrating the countless problems he encounters and failures he generates. Problems and failures that seem puzzling only to him. -- - Frank Krygowski