Gear slippage
09-01-09, 01:47 PM
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Gear slippage
Hi all......this is my first post as I just bought a 3 year old Trek 7100 and have been adjusting it to suit my body and type of riding. The only problem I'm experiencing is that on average I get a kind of slipping every half hour of riding time. It feels like it momentarily goes out of gear and then re-engages, but always in the same gear that it was in. I don't know if it's happening on the front gears or rear......it's over before I have time to look down to try and determine which it is.
Anyone have any ideas?
I appreciate the opportunity to gain from others' experiences - thanks forum members!
Tony
Anyone have any ideas?
I appreciate the opportunity to gain from others' experiences - thanks forum members!
Tony
09-01-09, 02:16 PM
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Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
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Often a random slippage like what you describe is caused by a stiff link in the chain. Backpedal slowly while watching as the chain comes off the bottom pulley of the derailleur. If a link or section of chain comes out and doesn't straighten immediately that's your problem. Clean and lube the chain properly and it should resolve, but sometimes needs a bit of a massage for the problem link to free up totally.
The other likely possibility is a slightly mis-adjusted rear derailleur, so your running with the chain not centered on the rear sprocket your using. From time to time it might try to shift, then "change it's mind" and stay where it is. Usually it'll be somewhat noisy when riding with a badly trimmed derailleur as the chain touches the adjacent sprocket.
Shift the bike into a middle gear and while looking from behind see if the chain is feeding cleanly and is centered on the sprocket. If not turn the barrel adjuster where the rear housing loop ends to move the RD over slightly until centered. Afterward, you'll need to run it through the gears and make sure it shifts smoothly in either direction. Use the same cable adjuster to get the best balance of crisp shifting and quiet running on the various sprockets.
If you google "adjusting rear derailleur" you'll find various tutorials.
The other likely possibility is a slightly mis-adjusted rear derailleur, so your running with the chain not centered on the rear sprocket your using. From time to time it might try to shift, then "change it's mind" and stay where it is. Usually it'll be somewhat noisy when riding with a badly trimmed derailleur as the chain touches the adjacent sprocket.
Shift the bike into a middle gear and while looking from behind see if the chain is feeding cleanly and is centered on the sprocket. If not turn the barrel adjuster where the rear housing loop ends to move the RD over slightly until centered. Afterward, you'll need to run it through the gears and make sure it shifts smoothly in either direction. Use the same cable adjuster to get the best balance of crisp shifting and quiet running on the various sprockets.
If you google "adjusting rear derailleur" you'll find various tutorials.
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
09-01-09, 03:11 PM
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Thanks very much FB........I now know where to start looking for the culprit. I appreciate you taking time to educate me!
Tony
Tony
