New Chain = slightly rough?

sometown
sometown Posts: 3
edited April 2014 in Road general
I've got a brand new 105 chain running on a 105 cassette that has 4 to 5 thousand miles on it. I knew I was due for a new chain, and when I dropped it on a ride, I decided to take it in. At the shop, they checked to make sure it wasn't so worn that the cassette also needed replacing. They said I'd caught it in time, and the cassette was still good.

However, on my first ride, I noticed an intermittent roughness on my pedal strokes...the kind of feeling I've known from a gritty BB.

I'm guessing that this is because the old chain and cassette had worn together, and while they were running smoothly, there is now a bit of contrast between the fit of the new chain and the mildly worn cassette?

Anything I should do about this?

Thanks.

Comments

  • homers_double
    homers_double Posts: 8,023
    I've always replaced them as a pair.
    Advocate of disc brakes.
  • rolf_f
    rolf_f Posts: 16,015
    I've always replaced them as a pair.

    Crikey - that's extravagent. You are buying cassettes three times more frequently than you need to! :wink:

    @OP - did you clean the drive train - eg take the cassette off and clean it properly and clean the chainrings and jockey wheels properly? It might just be that the silky smooth chain is making it obvious how crapped up your cogs are.
    Faster than a tent.......
  • zx6man
    zx6man Posts: 1,092
    I would say 4-5000 miles on a cassette is quite good if its only had one chain, I would have changed them both also with that mileage
  • markhewitt1978
    markhewitt1978 Posts: 7,614
    At 5k miles I would certainly be replacing the cassette too.
  • sometown
    sometown Posts: 3
    I probably am due for a thorough cleaning of the cassette. I clean the drivetrain fairly regularly, but just by spraying on Simple Green and aggressively attacking it with a scrub brush. It usually looks pretty shiny afterwards, but I know that's not the proper method.

    It's not unbelievably rough, but certainly not as smooth as it was a couple days ago. And I guess it's obvious that the discrepancy between new chain and older dirty-ish cassette and jockey wheels is the source of that. Hopefully I'm not doing any real damage to the new chain, and if I can do a proper cleaning this weekend, I'll get a few thousand more miles out of both?

    Thanks for all the quick responses!
  • rolf_f
    rolf_f Posts: 16,015
    BTW - missed the 5000 mile bit. I think you are doing well if the new chain isn't jumping on the cassette. That said, if it isn't jumping then I'd regard it as serviceable. If most of the 5000 miles are dry miles then life expectancy would be much greater. And you really need to run three chains in rotation to get optimum lifespan from the cassette.
    Faster than a tent.......
  • I'm firmly in the camp that says 5000 miles is far less than you should expect from a quality cassette -- on the other hand, that's too many miles to put on a chain, which could be your main problem; you may've let a worn chain wear your cassette. Around 2500-3000 miles, you should (should've) started checking the chain for wear, and replace it when necessary. Although the person at your shop said you'd caught the chain in time, I'd question that, and take the bike back in for a quick check. You may have to cough up for the cassette, though, having run a chain for 5000 miles.

    In late July last year, I got my fourth chain, together with my second cassette -- no problems before or after, because I never ran a chain much past 3000 miles.
  • Mikey23
    Mikey23 Posts: 5,306
    I'm on 7k and about halfway through my 3rd 105 chain. No issues up to now but I think I will change the cassette next chain