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Broken tooth on middle chainring, any problem?

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Broken tooth on middle chainring, any problem?

Old 12-11-11, 10:43 PM
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skieslord
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Broken tooth on middle chainring, any problem?

I just noticed that one of the teeth on my middle chainring is broken, I can see an uneven surface and seems broken, can I still riding like this without any problem or its better to get a new one?
I have been looking some and the prices are kind of high.
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Old 12-11-11, 10:51 PM
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FastJake
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Can you post a picture? Could just be the shape of the shifting ramp. Some of the older Shimano chainrings (especially the steel ones) look pretty funky and appear broken.

If it is in fact broken I wouldn't worry about it. One broken tooth out of how many? 32? 42? Probably not a huge deal.
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Old 12-12-11, 12:12 AM
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max5480
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One tooth isn't a big deal. But if it broke because of high usage and it looks like other teeth will start breaking off soon, it might be time to start looking around for a replacement, although if the the rest of the drivetrain is old, you might just want to leave it how it is because it has all worn together. replacing a chainring if the rest of the drivetrain is really old might not be the best performance upgrade.
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Old 12-12-11, 09:37 AM
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Yes, it has 32 teeth. I was thinking it could be a gate, however I have never seen it before, and certanly I can see another two teeth chipped already. Also most chainring teeth are worn. The crankset is a shimano deore xt and I can't find a replacement chainring (the small and large chainring are good shape) would any 5 bolt ring will fit?, I think is 94mm.
I will post a picture later tonigh when I get home, thanks for helping
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Old 12-12-11, 11:22 AM
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Engineered in, short teeth come a BDC*, for the crank stroke,
the part of the power input that is least, easing shift at that point,
so will be 2 on the chainring, since each crank has a BDC.

*Bottom Dead Center

Last edited by fietsbob; 12-12-11 at 11:25 AM.
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Old 12-12-11, 12:51 PM
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Originally Posted by fietsbob View Post
Engineered in, short teeth come a BDC*, for the crank stroke,
the part of the power input that is least, easing shift at that point,
so will be 2 on the chainring, since each crank has a BDC.

*Bottom Dead Center
Not sure that's universally true. SRAM Red cranks I'm looking at have short teeth on the big ring ~90 degrees from the crank arms.
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Old 12-12-11, 02:38 PM
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Originally Posted by fietsbob View Post
Engineered in, short teeth come a BDC*, for the crank stroke,
the part of the power input that is least, easing shift at that point,
so will be 2 on the chainring, since each crank has a BDC.

*Bottom Dead Center
I tough BCD stands for "bolt circle diameter"
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Old 12-12-11, 02:40 PM
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Nevermind I see is BDC not BCD..
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Old 12-12-11, 02:46 PM
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Not sure that's universally true. SRAM Red cranks I'm looking at have short teeth on the big ring ~90 degrees from the crank arms.
for those who are impatient and cannot wait 1/2 a rotation of the crank..
(nor read the terrain and shift when the loading on the chain is least,
being a skill, not a product)
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Old 12-12-11, 05:03 PM
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Originally Posted by fietsbob View Post
for those who are impatient and cannot wait 1/2 a rotation of the crank..
(nor read the terrain and shift when the loading on the chain is least,
being a skill, not a product)
I know most of the chainrings have a short tooth on the big ring, so you shift down better and you do not go any furder up, on the middle you still have to go up, will be this an disadvantage?
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