Chainrings

birdie23

Does this chainring need replacing?

I'm having a problem where it sometimes feels like my chain slips suddenly before instantly re engaging and there's a near constant ticking noise. I've changed chain and cassette. Cleaned jockey wheels. Leaving just my cranks and wheel that I haven't messed with.

Edit: can't embed the image for some reason. Only have Dropbox at my disposal at the moment so here's the link https://www.dropbox.com/s/6oh1g3g0f759yak/Photo%2023-07-2014%2007%2021%2042.jpg

arlowood

Shark's teeth effect indicate that your large chainring is pretty worn but they usually have to be much worse than your pic indicates to cause the problems you report.

From your description, another possible cause is the pawls on the freehub sticking so that they do not re-engage quickly enough and slip. This can often feel like chain slippage when it's not.

If you haven't serviced the freehub in a while then I'd suggest removing and cleaning it and checking that the pawl springs are all there and working.

birdie23

arlowood wrote:

Shark's teeth effect indicate that your large chainring is pretty worn but they usually have to be much worse than your pic indicates to cause the problems you report.

From your description, another possible cause is the pawls on the freehub sticking so that they do not re-engage quickly enough and slip. This can often feel like chain slippage when it's not.

If you haven't serviced the freehub in a while then I'd suggest removing and cleaning it and checking that the pawl springs are all there and working.

The wheel is actually brand new (warranty replacement) and my problems did start after using it...

Since it always happens when I've just been freewheeling too I suspect this is the problem. I'll get the wheel back to the shop.

Worth leaving the chainring for now then?

stevenb

Have the chain rings been removed/refitted lately?
They have to go on a set way so you get the best timing for gear changes.
Is your chain bent? Check for a lot of lateral flex. A lot of people ride bikes with a lot of cross gearing eg bigger coggs at the back and front or small at the back and front.

birdie23

I think what arlowood has said is right.

The chainrings have never been removed but the notch on the ring is in the right location anyway. The problem has occurred on two different chains, current chain has just over a 100 miles on it so it is fine.

I don't cross chain, though I think the damage it causes is exaggerated.

Worth adding, since paying more attention to this wheel I've noticed that it doesn't quite sound right when you push the bike forward (walking it into the bike rack at work, into the house etc) so I'm going to get the freehub looked at.

birdie23

It was the freehub. Unfortunately it was also terminal so that's warrantied now!