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Old 08-19-07, 12:22 AM   #1
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extreme chainring wear, is this normal?

so i was looking over my chainring (42T) on my single speed freewheel conversion and i've noticed about 4 teeth are mostly worn down. i put between 60 -100 miles a week on the bike and have been running single speed for around 3 months.

is this normal? i know i need to replace the chain, its old and has some links that are rusted (since it was the chain i got when i purchased this bike). i told the LBS where the conversion was done if the chain needed to be replaced to do it but he told me it didnt need it.

could that be causing an abnormal amount of wear and tear or did the LBS i went to sell and install some really low quality cranksets?

thx!

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Old 08-19-07, 12:50 AM   #2
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By extreme chainring wear, do you mean hooked teeth or teeth that appear worn down at the points, yet are at eerily evenly spaced intervals around the chainring perimeter, as if they could even be shifting gates for a front derailleur equipped bike?
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Old 08-19-07, 01:04 AM   #3
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you can see two teeth that are worn down. it is the exact same on the opposite side of the chainring.\

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Old 08-19-07, 01:53 AM   #4
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It looks like you've got a modern chainring designed for smooth shifting with pins and irregularly-shaped teeth. The teeth on your chainring appear okay - each tooth seems to be symmetrical. The worn-down result of running a stretched-out worn-out chain for many miles results in asymmetrical, shark-fin teeth, like this:

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Old 08-19-07, 02:04 AM   #5
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what about the two teeth just past the crank, they're worn down about half of their orginal size (its the exact same on the other side just past the crank).

sorry, im a little confused, i've only had this chainring for about 3 months. it shouldnt be this worn.
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Old 08-19-07, 05:32 AM   #6
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what about the two teeth just past the crank, they're worn down about half of their orginal size (its the exact same on the other side just past the crank).
The fact that the smaller teeth are exactly opposite each other tells me they were designed that way to be shifting aids. I wouldn't be concerned.
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Old 08-19-07, 06:13 AM   #7
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Are you having problems with shifting?

Oh, wait...
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Old 08-19-07, 09:40 AM   #8
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Are you having problems with shifting?

Oh, wait...
Haha
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Old 08-19-07, 09:53 AM   #9
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If it helps the OP's understanding: Chainrings are made for singlespeed applications that do not have the shifting gates. All the teeth are full and do help with keeping the chain on the ring. The ring you have is made for shifting. The shorter teeth help the chain shift to and from that ring in a double or triple setup, and are placed specifically at a point in the crank revolution where torque is lower.

My suggestion is to buy a singlespeed specific ring and rear cog. Some are even made for running a 1/8" chain for extra strength.
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Old 08-19-07, 11:47 AM   #10
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ok now it all makes sense! thanks wordbiker!
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