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Chainring wear
#1
I am seeing irregular wear in my front chainrings. As I rotate the crank (10-speed FSA Gossamer triple) I can see 1-2mm of radial runout as the tips of the teeth in one portion of the big ring are worn down more than the others. Inspecting the individual teeth shows quite a variety of shapes and wear patterns. I'd say there are about 20 adjacent teeth that are worn down with the remaining ~33 teeth looking fairly normal. Have you seen this before? Ideas? This is the setup that resulted in a broken Dura Ace chain a couple days back and I am trying to do some debug before installing a new $50 chain!
...j
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#2
Do you have low teeth opposite each other on the ring.
Some new rings (especially Shimano) have some low teeth which help with chain shifting.
It gives the impression of warn teeth even when new.
You should not have any distorted or misshapen teeth though.
[font=Trebuchet MS]Ride hard or ride home alone![/font]
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#3
Just got back from LBS and looking over new chain rings. The FSA chain rings come with unusually shaped and varied teeth from the factory. I saw at least four different types of teeth on the 53t ring. Now I'm not so sure that my rings are bad. It also looks like I can find a new FSA crank with BB for less than the price of a set of new rings for my Gossamer triple crank.
...j
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#4
This is interesting, because it shows that the shifting is not an exact science. Almost like an engineering correction or addendum to their own blue prints.
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
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#5
(02-21-2010, 02:21 AM)j beede Wrote:  Just got back from LBS and looking over new chain rings. The FSA chain rings come with unusually shaped and varied teeth from the factory. I saw at least four different types of teeth on the 53t ring. Now I'm not so sure that my rings are bad. It also looks like I can find a new FSA crank with BB for less than the price of a set of new rings for my Gossamer triple crank.
...j

Yeah, of course they do! Tooth shape is a lot of engineering you have to get right in order to get the shifting crisp and fast. So the teeth look quite different.
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