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Old 07-10-10, 04:31 PM   #1
fitzdawg
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One tooth shorter on chainring?

I just bought a Truvativ Elita 53x39 crank from Bikewagon, and when I opened the box I noticed that one of the teeth on the larger ring is shorter than all the rest. I've never noticed this before, and I was wondering if this is a defect? It definately hasn't been broken, as the darker coating on the teeth is intact (metal underneath not showing through). I wanted some info from more experienced folks to see if there is a defect before I contact the seller. Thanks!
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Old 07-10-10, 04:37 PM   #2
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This is common on almost all modern chainrings except those for single speed, or intended for the innermost position of doubles and triples. It's a shifting gate allowing the chain to move on and off the ring easier during shifts. You don't need it on the innermost sprocket because the chain is always lifting up from those, and never coming from a smaller neighbor. You'll notice similar cutouts, and/or thinning of certain teeth on each sprocket of any modern cassette.
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Old 07-10-10, 04:43 PM   #3
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Quote:
Originally Posted by FBinNY View Post
This is common on almost all modern chainrings except those for single speed, or intended for the innermost position of doubles and triples. It's a shifting gate allowing the chain to move on and off the ring easier during shifts. You don't need it on the innermost sprocket because the chain is always lifting up from those, and never coming from a smaller neighbor. You'll notice similar cutouts, and/or thinning of certain teeth on each sprocket of any modern cassette.
Thanks for the knowledge! I'm a noob when it comes to doing my own wrenching, so it's nice to have a forum like this for quick, concise answers.
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Old 07-10-10, 06:05 PM   #4
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To add a bit more info, some folks think the cutouts on the chainrings and sprockets actually lift the chain, but they're just for clearance to allow the chain to wrap properly onto the teeth of the ring or cog you're shifting to; the only bit that does any actual chain lifting are the pins riveted on the big ring (or middle ring as well, if it's a triple).
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