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chain skip problem(10 posts)

chain skip problemDog
Feb 3, 2002 6:26 PM
Today I replaced my chain and then went to ride some hard hills. Up one the last hills, when I went full bore out of the saddle, the chain jumped a cog on me while in a 53x17 gear. Scared the crap out of me. I looked, nothing wrong. Stood to go again, and it did it again, same gear. I wasn't shifting at the time, and it seemed to be firmly in gear.

This is Record 10, including the cassette (Ti, 11-23). The cogs don't appear to be worn, and besides, I have four or five cassettes, so I wouldn't think any one of them would get worn out in a little over a year. Any idea of what could be the problem? This is a little unsettling.

A few miles later I decided to see if it would happen in different cogs. So, I jumped to try again, hard at about 25 mph, and my right foot came unclipped on the up stroke. Wow, that got my attention. I swerved with my leg about 90 degrees horizontal almost to the centerline before regaining control. Good thing a car wasn't coming from behind. I thought for sure I was going down. That put an end to the testing for the day.

Any help?

re: chain skip problemCT1
Feb 3, 2002 7:04 PM
Maybe you're just too strong for your own good.... ;)

What chain did you use???

This is a typical cog wear issue but you say the cogs are newish. hmmmmm, all I can suppose is that the rear der is ever so slightly out of adjustment and the added torque from your monster mashing is enough to cause a skip.

re: chain skip problemChen2
Feb 3, 2002 7:42 PM
I'd suggest you play with the cable tension. Maybe it's trying to shift but doesn't quite. If my bike did that I'd try adding a little tension with the barrel adjuster.
re: chain skip problemgtx
Feb 3, 2002 10:12 PM
assuming your der isn't out of adjustment and your der hanger is aligned properly, it sounds like your new chain isn't getting along with that cassette. Either that or you are getting so much flex in your frame when you stomp on it that it's yanking on the der cable. Try it with a different cassette and see what happens. I think those ti cassettes are pretty soft--could be fried.
re: chain skip problemJuniorRacerFL
Feb 4, 2002 2:13 AM
This happened to me to but i was sprinting down a hill and i didnt even shift and right as i put pressure down it skipped and my foot flew down and i went over the handlebars and got messed up. But it was just the derailler slightly out of adjustment and once the lbs did that it got fixed.
thanks -- follow upDog
Feb 4, 2002 6:30 AM
*Campy chain, campy Permalink

*it did not shift, but stayed in one cog while skipping; wasn't making any noise like it was close to shifting

*it's never done this before, with about 12000(?) miles on this bike, so I doubt frame flex (unless fixed gear riding has helped that much :-)

*what about that adjustment screw that controls how close the der sits to the cassette? that have anything to do with it?

*will try diff cassette, and lock down those pedals first


One experience.Len J
Feb 4, 2002 6:40 AM
I installed a new chain one time & didn't get the link as tight as I should have. I was experiencing the same problem you describe. I tried everything, fiddled with all the adjustments & couldn't get it to stop. It was driving me crazy. Finally, while cleaning the chain & wiping off excess lube, I felt the (small) imperfection with my fingers (through the rag). Fixed the chain, fixed the problem.

BTW this was a shimano 9 speed chain, I would think the tolerances on the 10 speed would be even tighter (i.e. a smaller imperfection might be more noticable.

Just a thought

thanks -- follow upMel Erickson
Feb 4, 2002 7:08 AM
My bet is it's the cassette, but could be an adjustment. The "B" adjustment screw shouldn't cause this, especially since you only changed the chain. Could be a tension adjustment, worth a try. I think you're on the right track trying a different cassette.
re: chain skip problemVitusdude
Feb 4, 2002 7:25 AM
This is not uncommon when putting a new chain on with old cogs. Up till now, your chain and cogs have been wearing together. The new chain does not quite fit the wear pattern of the used cogs. 12000 miles on a cassette is a lot of miles. I find that the chain usually wears in after a hundred miles or so, stretching a bit to fit the wear of the used cogs. If not, you might consider replacing your cogs at this point.
Check the side to side play in the rear deraileurLC
Feb 4, 2002 9:59 AM
If you can move the rear deraileur more than a couple mm from side to side, then it could be worn out. With the advancement of 9 and now 10 cogs, the accuracy of the deraileur becomes even more important and any slop is bad news. If is seems fine, then I would lube your cables which is another thing that could be causing it.