Stickney

I have an old Trek 1200 with Shimano Biopace cranks. Under hard pedaling the drivetrain makes a creaking/grinding kind of noise. I cannot identify where it is coming from. I have tried cleaning, oiling the chain. Pedaling slow, fast, on the trainer. It doesn't seem to be coming from a derailer. I was wondering if anyone had developed something similar with Biopace cranks? My best guess is that the chain is flexing during the 'power' portion of the elliptical arc, however it only recently came about. Are my cranks in need of replacement? (I have put on probably 12,000 miles in the 6 years i have owned the bike. (bought used with little wear).

I am a bit flustered on not being able to hone in on the sound/issue.

Thanks!

Romulus

1. BB may need adjustemnt and tightening (usually click click clik once or twice per turn)
2. Pedals (clipless sometimes need lubed)
3. Chain rub (but that is usually easily identifiable metal on metal)
4. Check rear wheel to make sure it's in all the way
5. Check cranks, may need tightening

go to a shop and they may advise you some other stuff... I had a problem with a BB but works fine after minor adjustements

neil0502

1) Good link to help diagnose creaks/squeaks/clicks:

https://www.parktool.com/repair_help/...queaking.shtml

2) Give that biopace setup to Bobby Julich

Stickney

Thanks, just the kinda suggestions I was looking for. And yes, Mr. Julich's cranks have me interested Thanks Again, hopefully I can figure it out, or I am off to the LBS.

womble

I had a similar problem (occastional creak at certain pedal position, only under high stress). Turned out that the crankbolts needed tightening.

rmfnla

I have found this to be the most common cause of "creaking".