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Old 09-20-21 | 05:38 AM
  #23  
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jimmuller
What??? Only 2 wheels?
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Joined: Apr 2010
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From: Boston-ish, MA

Bikes: 72 Peugeot UO-8, 82 Peugeot TH8, 87 Bianchi Brava, 76? Masi Grand Criterium, 74 Motobecane Champion Team, 86 & 77 Gazelle champion mondial, 81? Grandis, 82? Tommasini, 83 Peugeot PF10

Originally Posted by Road Fan
True dat, but Dr. Jim is looking for what we see. If it was mine, this is one of the reasons I’d put her up on the stand and make a better measurement. I just did this on Mrs. Road Fan’s Campy triple, and the big ring is flush with the derailleur outer plate when the chain is on the middle ring.
I see what you are saying, or rather hear what you are saying, or more accurately, see what you were typing, but [MENTION=175113]thook[/MENTION] has it right. That proximity is merely an optical illusion, or rather optical delusion, from the perspective of the camera lens and from the downward movement angle of the cage when centered on the middle ring. FWIW, that FD is a new-ish Simplex triple. I don't know if it is still made but it was one of those new, seemingly retro models. It works extremely well. I bought it some time in the last decade to replace a true vintage Simplex triple which was never better than just okay. The new one made all our front shifting problems disappear. (They probably didn't go away but are hiding under the bed, and will jump out to haunt us at some random time in the future.)

Originally Posted by Hondo6
That's actually a pretty impressive statement about just how strong the original chain really was. That's over 6 1/2% elongation - which means a helluva lot of metal had been worn away and it still didn't break under load.

Was the original chain also SRAM?
Yes, the previous chain was SRAM PC870, like this one. A wear spec I had seen here in BF was to replace a chain at 10% elongation which seem like a lot, or else I totally misunderremember it, or rather misoverremember it. Of course, we are not a monster-masher team, total team weight under 275 lbs and I prefer to spin rather than mash. In any case, we are taking about 1 inch of metal spread over 112 pins and some of the wear might be on the sleeves instead of the pins. So it's a bunch, but apparently not yet fatal to the chain. (That chain got tossed into the recycle bin along with the rings.)

Now you wanna' talk about chains breaking, I once tried restoring a Motobecane Le Champion which came to me with all its original parts. So I assembled it for an easy test run around the block, got about 30 yards and the chain broke. I believe the chain was a SedisSport but perhaps not. Closer inspection showed that a third of the outer side plates had visible cracks. That chain got retired immediately. I eventually sold bike and parts to another BF member. The full restoration was bigger than I wanted to jump into.

Another chain-break episode involved the Masi when I was about 30 miles from my car into a planned 75 mile ride. Apparently the Quick Link broke or came apart. I couldn't find the missing half along the 50 yards of roadway where it must have happened. I wondered if there was a bike shop in the nearest town. After foot-pedaling the bike for a quarter mile I asked someone on a riding mower in his front yard. He said the guy who lived next door was an avid cyclist who had just come in from a ride so I should go ring his doorbell. Wow, talk about being in a lucky place and time. The guy did indeed have a chain tool I could use to splice my chain. He had to show me the chain ring from his older-days track bike. The teeth on that ring looked like needles. We had a great conversation and I made it safely back to the car. I have carried a spare Quick Link pair ever since. For want of a few grams of metal the ride was lost, but not the rider or the horse.
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Last edited by jimmuller; 09-20-21 at 05:56 AM.
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