Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

Compact Crank - Cassette

Options
  • 24-11-2020 7:42pm
    #1
    MayoSalmon
    Registered Users Posts: 2,257 ✭✭✭


    Hi folks,

    Newbie question here...

    My bike has a compact crank 50x34 and Cassette on the back which is 11s -34t.

    I am wondering what cassette can I drop down to for the turbo current one is quite expensive and also probably unnecessary for turbo use?!

    Thanks


Comments

  • Options
    #2
    TheBlaaMan
    Registered Users Posts: 3,444 ✭✭✭TheBlaaMan


    Presume it is a direct drive turbo where you remove your rear wheel? If so, then any compatible (make) and speed (10, 11 or 12 etc) cassette should be fine as long as you dont get such a small biggest sprocket as to suffer lots of slackness in the chain. The chain will be measured to work with 50 chainring connected to innermost 34t sprocket and this is when the chain is at its most taut. Go a 25t sprocket on the turbo and now - at its tightest - it will be 'sloppy'. I'd say you'll need to get a 11/12 to 29t cassette or something like that, no smaller.....


  • Options
    #3
    Daroxtar
    Registered Users Posts: 4,343 ✭✭✭Daroxtar


    Assuming that your cassette is Dura Ace or Ultegra, a 105 cassette will do exactly the same job for a substantial reduction in price.


  • Options
    #4
    nilhg
    Registered Users Posts: 5,144 ✭✭✭nilhg


    TheBlaaMan wrote: »
    Presume it is a direct drive turbo where you remove your rear wheel? If so, then any compatible (make) and speed (10, 11 or 12 etc) cassette should be fine as long as you dont get such a small biggest sprocket as to suffer lots of slackness in the chain. The chain will be measured to work with 50 chainring connected to innermost 34t sprocket and this is when the chain is at its most taut. Go a 25t sprocket on the turbo and now - at its tightest - it will be 'sloppy'. I'd say you'll need to get a 11/12 to 29t cassette or something like that, no smaller.....

    I don't get this, the 11-34 cassette will have a 25t ring somewhere inside in it, if it's not sloppy there why will it be sloppy on a 11-25?

    OP my understanding is you can easily go to a cassette with a smaller gear range (while keeping the same number of cogs) than what you have, it's only if you wanted to increase the range that you might run into problems.


  • Options
    #5
    TheBlaaMan
    Registered Users Posts: 3,444 ✭✭✭TheBlaaMan


    nilhg wrote: »
    I don't get this, the 11-34 cassette will have a 25t ring somewhere inside in it, if it's not sloppy there why will it be sloppy on a 11-25?

    OP my understanding is you can easily go to a cassette with a smaller gear range (while keeping the same number of cogs) than what you have, it's only if you wanted to increase the range that you might run into problems.

    @nilhg, you are right and I've badly worded the point I was trying to make, which I have mangled somewhat. With a cassette with smaller inner sprockets than on the bike, the length of the chain could make for sloppy shifting when at its loosest, but - as you say - not as big an issue as if you were using a cassette with a greater range.
    Sorry for any confusion


  • Options
    #6
    MayoSalmon
    Registered Users Posts: 2,257 ✭✭✭MayoSalmon


    Thanks for the input lads.

    Iv gone for 11-30 cassette in the end


  • Advertisement
Advertisement