I bought this road bike as my first road bike in 2011. I have not changed the chain or any parts on it since then and I bike on it almost daily. It's been running great, but sometimes I have trouble changing gears and I feel like the issues are getting more frequent. I had a major accident on this bike in 2012 learning how to use the clipless pedals but the bike landed on the opposite side of the cassette.

Are the scratches in the picture below "normal" for a bike this old? Do I have to replace any parts? Is it safe to ride as-is?

Here are some pictures: enter image description here enter image description here

  • 1
    Don't guess about the chain. Buy an inexpensive chain stretch gauge and check the chain. And a good bike shop will have a special gauge for checking sprockets for wear. (And in order to "eyeball" whether a sprocket is worn we'd need to see the sprocket without a chain on it.) Commented Mar 14, 2015 at 3:13

3 Answers 3


That is a picture of the chain ring not the cassette.

If the cassette is worn out then the chain is worn out.

Cannot tell anything about the larger chain ring but the small chain ring is not in bad shape.

This is the order they wear out: chain, cassette, then chain ring.
You get 2-3 chain per cassette.
And typically 2 cassette per chain ring.

If you have ridden the bike daily since 2011 then safe to assume you need a new chain.
Easy to check with a chain wear tool - they are relatively cheap.

If you continue to ride on a worn chain the problem is that you wear cassette and chain ring faster.

It looks like you lube the chain which is a good thing. But you need to clean the chain every few lubes also.

  • Thanks. I still haven't learned all the parts and I get them confused. I was mostly trying to point out the scratches.
    – RommelTJ
    Commented Mar 13, 2015 at 19:48
  • Scratches is just a from a jumped chain - no big deal.
    – paparazzo
    Commented Mar 13, 2015 at 19:59
  • 2 cassettes per chainring? If its a road bike, thats pretty quick.
    – Batman
    Commented Mar 13, 2015 at 22:11
  • @Batman OK then what do you get? That is what I typically get.
    – paparazzo
    Commented Mar 13, 2015 at 22:27
  • At least 5000 miles on a cassette and 20000 miles on a chainring.
    – Batman
    Commented Mar 13, 2015 at 22:30

Use a chain wear gauge to see if the chain needs replacement (e.g. Park Tool CC-3.2).Generally, these err on the side of replacing a bit early, but if you want to be pedantic about it, you can use the Sheldon Brown link below to measure with a ruler.

As for the sprockets or chainrings, I'll defer to this page by Sheldon Brown. The upshot is that worn teeth look like ramps and a non-stretched wont sit properly in the sprockets as shown in the image below (from Sheldon Brown)

enter image description here

  • Yeah, +1. I tend to avoid the use of a chain tool because I think the cycling industry is far too keen for us to buy dedicated tools where standard tools will suffice. Because the pitch of a chain is a half-inch, it is useful for the ruler to be imperial, and if you can get one long enough (13" or longer iirc) you can just read off the scale.
    – PeteH
    Commented Mar 13, 2015 at 19:25
  • 1
    @PeteH - To use a ruler you need three hands, and you get the ruler all greasy besides. A chain stretch gauge is cheap and easy to use and there's no good reason to not have one. Commented Mar 14, 2015 at 3:15

Those scratches are due to the chain rubbing as it shifts between chainrings. They are more noticeable on your bike than most because you have black chain rings. A Park chain wear gauge is a good way to tell if your chain is worn. Alternatively, you can measure with a ruler as described, but it's much easier if you remove it from the bike. The figure I use was 1/8" of chain stretch per foot was too much. If you let the chain stretch too much it will wear out your cassette as well.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.