cassette to match compact chainset

lifeofbrian
lifeofbrian Posts: 2
edited January 2008 in Road beginners
when I switch to a 50/34 chainset do I need a 12-27 cassette to make the most benefit from it - for climbing that is? - cheers

Comments

  • redddraggon
    redddraggon Posts: 10,862
    50-34 and 11-25 seems like a good combination to me.
    I like bikes...

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  • JWSurrey
    JWSurrey Posts: 1,173
    You can check the advantages of different ratios using the gear-inch chart on the sheldonwbrown.com website.

    I run a 13-29 on the Campag. bike - which requires a medium cage deureilleur - Several posts have said that if you're careful and don't cross-over the chain, the short cage will work (Personally, I wouldn't).
    34-29 is a superb winch gear!

    Of course, the trade-off is a greater inter-ratio spread, which can be a bit annoying if you're riding in a group.
    I find my 12-27 inter-ratio spread OK. The 13-29 is a bit more noticable, however by the time i'm that far up the cassette, I'm not usually bothered.
  • nolf
    nolf Posts: 1,287
    I've got a 50/34 and 12-27 (10 speed).

    It's got good cruiser gears for the big chainring, and a small enough crawler gear to get up pretty much anything without stopping.

    Personally I'm thinking of getting some new wheels and would probably get them with a 12-25 so that I have more inbetweeny gears- maybe even a 12-23 if I wanted to race on it.
    "I hold it true, what'er befall;
    I feel it, when I sorrow most;
    'Tis better to have loved and lost;
    Than never to have loved at all."

    Alfred Tennyson
  • John C.
    John C. Posts: 2,113
    What was the lowest gear you had before changing to a compact? Be it double or triple
    number of teeth on smallest chain ring multiplyed by 27 devided by the number of teeth on the largest of your cassette
    so if you had a triple with a 30 granny and a 12-25 cassette that works out at

    30 X27 / 25 = 32.4

    A double would be , say 39 front and if you had a 25 rear

    39 X27 / 25 = 41.2

    So work out what you have on your current bike and then knowing that a compact is 34 work out what size cassette you need to keep the gearing the same.

    Hope that has been of some use, all the best for the NEW YEAR
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • a_n_t
    a_n_t Posts: 2,011
    I run 11-23 with my 50/34. gives me a 38.8" with 34/23

    used to run 42/27 which gave 41" and I managed to drag my arse up holme moss with that in my youth!
    Manchester wheelers

    PB's
    10m 20:21 2014
    25m 53:18 20:13
    50m 1:57:12 2013
    100m Yeah right.
  • John C.
    John C. Posts: 2,113
    We can all pull our selves over hellish hills in high gears I've done Boltby on 42/25 but I wouldn't dream of having that as my lowest gear. Remember that 15% hill at 100 miles will feel like 30%.
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • a_n_t
    a_n_t Posts: 2,011
    John C. wrote:
    Remember that 15% hill at 100 miles will feel like 30%.

    then i'll just haul my arse over that too! :D
    Manchester wheelers

    PB's
    10m 20:21 2014
    25m 53:18 20:13
    50m 1:57:12 2013
    100m Yeah right.
  • John C.
    John C. Posts: 2,113
    In 2008 Rydale Rumble and the Fred Witton that hill on the 100 mile mark IS a 30%, My gears will be low as will my ars* at that point :oops: :lol:
    http://www.ripon-loiterers.org.uk/

    Fail to prepare, prepare to fail
    Hills are just a matter of pace
  • carlstone
    carlstone Posts: 602
    when I switch to a 50/34 chainset do I need a 12-27 cassette to make the most benefit from it - for climbing that is? - cheers

    Thats what I have on my racer. Good enough for an unfit me and has the added advantage of being the biggest spread of gears you can get away with when using an Ultegra (or any Shimano ASFAIK) short cage mech.

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