I have a 2001 Raleigh R600 road bike. It wasn’t ridden much when I got it, and I’ve recently been putting some miles on it. It was a 3x9 speed with 9 speed components. I just changed:

  • Wheels
  • Cassette: to a 10 speed with 34t largest (was 28t)
  • Rear derailleur to a short cage 10 speed
  • 10 speed chain

When I put a lot of force on the pedals (standing up or high gear and push hard), the chain comes off the chainring and makes a grinding/cranking sound.

LBS said components are not compatible, but my shifting is 95% optimal on the rear derailleur. I even can get into the largest cog. If I’m not pedaling with a ton of force, it rides very smoothly and shifts fine. Chain length should be good based on my calculations.

I didn’t change the chainrings, and they could be worn. Is it that or that my components aren’t compatible and it’s misaligned somehow?

  • 1
    Are you using a 9-speed chain? Aug 19 '20 at 23:58
  • 2
    Which chainring does the chain come off of? It’s likely that they’re just worn badly. Make sure to put a new chain on too while you’re there.
    – MaplePanda
    Aug 19 '20 at 23:59
  • I wonder if the bottom bracket is loose, or the right crank arm is somehow flexing to cause the chainring to twist sideways. Aug 20 '20 at 0:21
  • 5
    Can you give is a clear photo of the side of your chainring? Need to see the teeth, I'm anticipating its worn.
    – Criggie
    Aug 20 '20 at 1:25
  • 1
    Short cage AND 3-speed front AND 34-tooth rear spells problems to me. That is most certainly outside the maximum teeth specifications, hence the LBS statement But it could work. The chain coming off under load points at worn chain-ring(s).
    – Carel
    Aug 20 '20 at 9:22

I've done something similar - mixing a shimano 105 9 speed triple chainset with a 10 speed chain and a 10 speed cassette and 10 speed derailleur. It all worked adequately. It ran fine after a lot of tweaking.

However my chainrings were worn and I had similar slips while climbing. So I scored some new-old-stock chainrings for the big and middle rings, and all my slipping problems went away.

They happened to be biopace, but that's not relevant.

  • Thanks Criggie! Sounds like you did the same thing and that worked for you. I’m gonna get some new chainrings and see if that helps. For the other answers, I’m using a 10 speed chain. The crank arm was loose, was tightened, and did not solve the issue at all. LBS said the bottom bracket is a bit worn and could be replaced but has some life in it. Will update with a picture of the chainring Aug 20 '20 at 14:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.