Chain rattle in highest gear
05-30-20, 05:56 AM
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Chain rattle in highest gear
I am new to cycling, my road bike has 2*7 shinano gears.
When in the highest gear, at speed, the chain rattles when i push on the right pedal.
I cant replicate the noise in the garage with the bike elevated.
I have tried adjusting the rear h spring. Tightening it, i could no longer go into high gear as expected. Loosening it, i can go into high gear again, but further loosening did not eliminate the noise and doesnt seem to make difference.
The front derailleur looks ok visually there is a gap both sides but i cant be 100%.
What are the steps to debug and fix this?
When in the highest gear, at speed, the chain rattles when i push on the right pedal.
I cant replicate the noise in the garage with the bike elevated.
I have tried adjusting the rear h spring. Tightening it, i could no longer go into high gear as expected. Loosening it, i can go into high gear again, but further loosening did not eliminate the noise and doesnt seem to make difference.
The front derailleur looks ok visually there is a gap both sides but i cant be 100%.
What are the steps to debug and fix this?
05-30-20, 09:07 AM
#2
Constant tinkerer
Do make sure the rear derailer limit screws are set correctly, but this is almost certainly a case of it rubbing on the front derailer cage. It won't show up in the stand but when you start pedaling you're flexing things just enough to make it rub. Check the clearance there. If needed, move the cage outward a tiny bit by loosening the H limit screw and/or increasing the cable tension.
05-30-20, 09:11 AM
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It's possible that a, your frame is flexing under load and thus causing the front derailleur to rub against the chain. (no likely because you can duplicate it on the stand) or b, your chain and/or upper pulley on the rear derailleur are hitting the cog. If b, is the cause, then adjusting the B-bolt on the derailleur might eliminate that.
Other causes might be a worn smallest cog or a worn chain if the smallest cog isn't used much. Or it could be a slightly bent rear derailleur cage or hanger.
Cheers
Other causes might be a worn smallest cog or a worn chain if the smallest cog isn't used much. Or it could be a slightly bent rear derailleur cage or hanger.
Cheers
