# TREK 800 Crankset Problem



## parnavaz (Mar 31, 2011)

Hello,

Few Years Ago I have bought a used trek 800. Till now it worked great but not so long ago the chain started to jump over the teeth of crank ring.Especially over the larger one.
I have decided to buy a new crankset.

I found one on amazon but do not really know whether it will fit my bike or not.
Could you please let me know whether they are compatible or not.

attached are the photos of my bike's crankset and the link of one I want to buy.



Uploaded with ImageShack.us

https://www.amazon.com/Shimano-FC-M...TF8&coliid=I2PIGAAW8GUUXQ&colid=2XXV9ILEWSWSJ

If this one won't fit could you tell me which one will and where I can buy it?
Or at least buy a crank ring? Or just write a model or type of my bikes crank?
I tried to look for any text on it but could not succeed. (


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## parnavaz (Mar 31, 2011)

Hey, Can anyone help me with this issue.


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## AndrwSwitch (May 28, 2009)

I don't know if you're still paying attention to this thread, being three weeks ago and all...

I'd be a little surprised if it's a problem with the crankset, although it's hard to tell from your picture.

Your drivetrain is filthy. Clean it, and measure your chain. I think it's more likely your chain is worn out, or you're feeling skip at the cogs, either because of a worn out chain, worn out cassette/freewheel, or misadjusted shifter.

http://sheldonbrown.com/chains.html#wear

The crank in your link would be a little nicer than what you have. You're likely to need a new bottom bracket too. About a $30 item, and requires some special tools to install. Your shop can probably handle the entire swap for a minimum labor charge.


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## PlatyPius (Feb 1, 2009)

Chainrings on that crank are not replaceable.

The Alivio crank will fit fine.

Your drivetrain is so disgustingly filthy that I'm surprised it shifts or moves at all.

I would guess the main issue is your chain, however, your crank and cassette/freewheel are probably trashed as well.


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