Bicycle Mechanics - Chainring replacement?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA

View Full Version : Chainring replacement?

dukes909
10-13-11, 07:06 AM
How close to needing to be replaced are these chainrings? And, what's up with that tooth in the middle chainring that looks like it's been sawn off?

http://i.imgur.com/nnlcdl.jpg

http://i.imgur.com/QlfWel.jpg

http://i.imgur.com/BOtxSl.jpg

dabac
10-13-11, 07:42 AM
How close to needing to be replaced are these chainrings?
Hard to tell, just like that.
I prefer to put a length of new chain on, and then try to lift it a little.Let's say I have a 3/4 of chain wrap, with chain hanging down on both left and right. If I then can "get air" between the chain and ring when lifting a little at the top, I might consider replacement. The profile as such doesn't look too bad to me.


what's up with that tooth in the middle chainring that looks like it's been sawn off?
Well, either it's tooth that's sheared off at a clumsy gear change sometime, or it's a deliberately trimmed tooth to improve shifting.
kycycler
10-13-11, 08:01 AM
From the pictures it appears that the chain rings are ok. But hard to tell. The teeth do not appear to be shark toothed. As for the middle chain ring, The tooth is made that way on purpose to aid in shifting.

Looigi
10-13-11, 08:26 AM
The big rig looks due to me. Middle and small look OK.
Homebrew01
10-13-11, 09:54 AM
It's pretty hard to wear out the big chainring. Many chainrings look worn due to the way they are made to improve shifting. Yours looks fine.
bradtx
10-13-11, 10:25 AM
dukes909, I think you're good to go for a good while yet.

Brad