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Cassette options for 105 rear mech

mikey2341mikey2341 Posts: 170
edited January 2013 in Road buying advice
I'm hoping to attempt the Etape and the Fred Whitton this year and wondered what would be the biggest cassette I can get away with. Could I fit a 12-28 or even the sram WiFi cassette??


  • maddog 2maddog 2 Posts: 8,114
    it depends on which mech you run...

    You can run a 11-36 if you want but you'll need a MTB mech.

    If you want to retain your existing mech then you need to tell us what model it is (code as well if possible) and what speed you are running (8/9/10 etc).

    If you are happy to buy a new mech too, then tell us what shifters you run, and what speed.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • jibberjimjibberjim Posts: 2,810
    Which 105 mech? (the 5700A version will go up to 30 as per spec and probably 32 on all bikes)

    11-28 will work for sure.
    12-30 will probably work on most bikes.
    12-32 may work on some bikes.

    If it works will probably depend on things like chainstay length and Q-factors and such like, all you can do is try it.

    Shimano 10 speed comes in up to 32, (or indeed 36 even) but yes SRAM 10speed will be compatible.
    Jibbering Sports Stuff:
  • mikey2341mikey2341 Posts: 170
    I think its the 5700 105 (it's on a boardman team if that makes a difference

    I might try the 30, that sounds like it could be the most cost effective option!

  • Gary DGary D Posts: 431
    If that is a short cage rear mech (which it looks like from the photo) then according to the Shimano spec sheets, you can go up to a total capacity of 33 Teeth. Allowing for the 16T difference you already have on the front, that leaves 17T. Therefore, an 11-28T or 12-28T cassette would be fine. A 12-30 would take you just outside the capacity, but it could probably be made to work if you got the chain length and indexing adjustment just right. The Shimano specs are a little conservative in my experience.
    Otherwise, you would have to change the rear mech for a long cage one where you can then go up to a 39T total difference. However, if you were changing the rear mech, as Maddog said, you would probably be better to fit a MTB mech.
    All of the informartion you need is on the Shimano website - once you can figure what all of the numbers mean :lol:

    Hope that helps.
    Oh and I feel like I've been raped by an Orangutan :shock: And I've got legs like Girders :lol:
  • mikey2341mikey2341 Posts: 170
    Thanks for this, The cassette isn't too dear from Rose bikes, so I'll look at getting both of them. Cheers for your help
  • maddog 2maddog 2 Posts: 8,114

    11-28 should be fine. If you need lower then 11-32 and a mech change. Or a 33t chainring.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
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