How do you know when your chain ring is worn?

mallorcajeff

Hi all
I know you can measure a chain of couse but is there any way of measuring a chain ring? My Dura Ace 53/39 has done 10k now and wonder how many miles you should get out of one (realistically) and I know the teeth wear down but how worn is too worn time for a new one? I ride 80% in the big ring and probably swap just the big one first. It works faultlessly but I like to keep everything in shape and serviced and clean all the time, so maybe just a bit paranoid.
Any ideas? thanks

keef66

I've never replaced one, but I gather when the teeth start to look like shark fins or the chain skips under load despite new chain and cassette.

cycleclinic

As above really. You will know if they are worn as they will be giving problems.

andrew_s

If the teeth come to a sharp point in the area about 90deg round from the crank arm, the ring is worn.

The trouble with waiting for it to slip is that it will initially only slip under pressure, but slipping damages the teeth so it slips more easily next time. It can go from first slip to unable to ride up a moderate hill very quickly. If you are unlucky in your route choice, it may be awkward getting home.

A worn chainring (observe the teeth just right of the drop pin that have been wrecked by chainslip):

mallorcajeff

wow thanks for the info mines still got a fair bit of life in it yet. Im glad as i dont want to have to buy a 7900 ring every year. thanks

Hoopdriver

You should get an awful lot of mileage out of a chainring. No doubt there will be people on here who swear they go through one every season, but truly you should get years of wear out of one - at least I certainly do

mallorcajeff

i thought so ive put 10 thousand miles on mine in 11 months so hopefully its not dead yet then. thank god