Compact crank: chain coming off?
10-17-06, 05:22 PM
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Compact crank: chain coming off?
I bought a TCR w/compact crank the other day, (50/34), and I took it out on Saturday and yesterday with no issues, in fact I'm in love with the gears. Today however, I was on a ride and, when going from the big to the small ring, the chain just kept going, clearing the 34 and going right off altogether. Is this a typical compact crank thing or more of an adjustment thing?
10-17-06, 05:24 PM
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There is nothing inherent to compact cranks that would cause it. Check your front derailleur adjustment: https://parktool.com/repair/readhowto.asp?id=75
10-17-06, 05:26 PM
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Originally Posted by 'nother
There is nothing inherent to compact cranks that would cause it. Check your front derailleur adjustment: https://parktool.com/repair/readhowto.asp?id=75
10-17-06, 05:30 PM
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Originally Posted by Basscycle
Great article, I had no idea that Park had that stuff on it's site, thanks!
10-17-06, 07:02 PM
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If you switched from a standard crankset, you probably need to move and then readjust the FD. It took me a couple of rides to dial in my FD after switching to a compact. No biggie.
10-17-06, 07:09 PM
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Originally Posted by urbanknight
If you switched from a standard crankset, you probably need to move and then readjust the FD. It took me a couple of rides to dial in my FD after switching to a compact. No biggie.
10-17-06, 07:10 PM
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Originally Posted by Basscycle
I bought a TCR w/compact crank the other day, (50/34), and I took it out on Saturday and yesterday with no issues, in fact I'm in love with the gears. Today however, I was on a ride and, when going from the big to the small ring, the chain just kept going, clearing the 34 and going right off altogether. Is this a typical compact crank thing or more of an adjustment thing?
FSA gossamer 50-34, 12-25 Ultegra and Ultegra FD
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10-17-06, 08:37 PM
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The FD is a relatively crude thing when you think about it. It kind of just wacks the chain off the big ring and gravity takes over.
When I switched, I had the same problem. Watching closely on the bike and on the stand, it appeared that the chain wanted to fall and ride on the tips of the 34T ring. I got it better through adjustment, but could not get it perfect. Wondered if it was a function of the 16T difference vs. the standard 14T drop.
Bought one of those chain watchers and no more problem. I honestly don't know if it ever falls off at all under normal conditions.
Switched to 10 spd this year, left the chain watcher on. Notice no difference.
The only time I ever notice a potential drop (or an actual drop on my triple) is when I am shifting at the same time I'm running over a very very bumpy section of road.
When I switched, I had the same problem. Watching closely on the bike and on the stand, it appeared that the chain wanted to fall and ride on the tips of the 34T ring. I got it better through adjustment, but could not get it perfect. Wondered if it was a function of the 16T difference vs. the standard 14T drop.
Bought one of those chain watchers and no more problem. I honestly don't know if it ever falls off at all under normal conditions.
Switched to 10 spd this year, left the chain watcher on. Notice no difference.
The only time I ever notice a potential drop (or an actual drop on my triple) is when I am shifting at the same time I'm running over a very very bumpy section of road.
