kv501

I have a 2009 Trek 2.3 which I bought used this winter. The original owner said he put 1,900 miles on it, which was on the odometer of the computer he had. I have put 300-400 on it myself between the trainer and the road since I bought it. I checked the chain last week and it was a 1/16" or a little over so I bought a replacement. I didn't pick up a new cassette because I figured that it would still be good, but the cassette is starting to act up. I had it skip on me a few times last night (first ride with the new chain), and the shifting was a little iffy sometimes. Before, when I had the old/old combination on the bike it shifted like a dream.

I realize that every situation is different, but could the cassette be worn to the point of replacement after 2500 miles? I don't know if the guy ever replaced the chain, so it might be a matter of just going to long with a worn out chain I guess. I don't have a problem buying a new cassette; I was just wondering if it's typical for a cassette to wear after this amount of miles or if using a chain for too long would accelerate it. Thanks.

Retro Grouch 

It is what it is.

Using a chain for too long will definitely accelerate cassette cog wear. If a lot of those miles were in the same cog, that cog would wear more quickly than the rest.

kv501

Thanks. I ordered a new one this morning. I just wanted to make sure that it wasn't abnormal and that I should be looking at something else also.

kv501

I did have one other question and didn't feel the need to start a new thread. When I ordered the new cassette, I got a 12-25 instead of the 11-25. I rarely use the 11 and there are very few descents where I can remember spinning out the 50/12 (flat as a board here). The 15-17 gap was annoying for me at times in the wind we have. If I get strong enough to spin out the 12 I'll just buy a new cassette.

Question: Will I have to make any derailleur adjustments by doing this?

From: 11-12-13-14-15-17-19-21-23-25

To: 12-13-14-15-16-17-19-21-23-25

deacon mark

Normally no but just a new cassette can need a touch of tuning. It should not need much if it works now.

rdtompki

If it does need tweaking to to either the Park Tools or Sheldon Brown websites for instructions.

mechBgon

Side note: as you may already be aware, there's a 1mm spacer included with Shimano 10sp cassettes. Make sure you put one onto your hub before installing the cassette.

kv501

Thanks for all of your help.