I recently dragged out my old road bike (vintage Dura-Ace) and replaced the chain and gear cluster. Everything runs smoothly and shifts fine on the 42 front chainring, but when I apply a very strong pedal pressure such as sprinting up a hill, everything in the drivetrain starts slipping, crunching, etc. I measured the chain and found it was a bit too long and knocked out 2 chain links to bring it to the proper length. Yet it still [censored] around under pressure. However, I noticed that if I shift into the large 53 front chainring and apply this aggresive pedal pressure, all runs smoothly. Could it be that my 42 front cog is totally worn and causing this problem, or could it be something else, like perhaps the derailleur pulleys?
Thank you very much for your help - any would be greatly appreciated!
I doubt it's the der pulleys. Could very well be, as you suggest, a worn 42 up front.
Is your new rear cassette and chain of the same type (e.g., Shimano) as your rear der, or are you mixing components from different manufacturers?
Actually I was experiencing some gear crunching before I changed the gear cluster and chain (Hyperglide). I'll replace the 42t chainring and see how it goes, as things seems to point to that as the culprit.
