Bicycle Mechanics - Drive Train, HELP!

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View Full Version : Drive Train, HELP!


davidmcowan
06-04-07, 09:31 PM
Just measured my wife's Trek1000 chain and it is overworn easily at 1%.

I think I need to replace chain and rear cassette and possibly front triple chain ring. I think most parts are Sora, I'm hoping you all can help me find the cheapest way to do this. I've got all the tools I just need to know where I can get these parts for cheap. Can I buy front chain rings seperate somewhere so I can just replace them instead of the entire crank? Any online stores or ebay where I can get a package to replace this stuff?

Please help me do this affordably, we're social workers and the money doesn't flow around here!


neil0502
06-04-07, 09:48 PM
Whoa there, cowboy.

Why do you think the chainrings need replacing??

How did you measure the chain for stretch?

How do the cogs look??

You may want to give the local bike shop a couple of bucks just to help you verify your findings. You may be able to get the parts cheaply there. If not, then a quick Google search for the actual parts you need ... or Jenson or Harris or Nashbar or Performance ... or any of a number of sites can sell you reasonably priced replacements.

I'd just get your assessments verified first. You could well be right, but I have a funny feeling here....

Bobby Lex
06-05-07, 04:46 AM
Whoa there, cowboy.

Why do you think the chainrings need replacing??

How did you measure the chain for stretch?

How do the cogs look??

You may want to give the local bike shop a couple of bucks just to help you verify your findings. You may be able to get the parts cheaply there. If not, then a quick Google search for the actual parts you need ... or Jenson or Harris or Nashbar or Performance ... or any of a number of sites can sell you reasonably priced replacements.

I'd just get your assessments verified first. You could well be right, but I have a funny feeling here....

+1 to this question. What does the "1%" represent?

Bob


I_bRAD
06-05-07, 05:13 AM
Start with a chain if it is indeed worn. Go from there.

davidmcowan
06-05-07, 07:28 AM
A picture is worth a thousand words:

Bobby Lex
06-05-07, 08:11 AM
A picture is worth a thousand words:

Gottcha.

Check out this link for an excellent explanation of chain stretch and cog/chainring wear, with photos:

http://www.sheldonbrown.com/chains.html

Ultimately, (as has been suggested above) I would replace the chain first. If you continue to have shifting problems which cannot be resolved with cable and screw adjustments, then I would replace the cogset. As to the chainring, it is a rare feat to actually wear out a big chainring, so I doubt that you would need to do that. But it is theoretically possible that the chainring is worn as well. (Although that does not appear to be the case from your photo).

Bob