Converting a Compact to a Double

Cormac
Cormac Posts: 18
edited April 2010 in Workshop
Hi All,

I've got a Ultegra Compact 50/34 Chain Ring on my bike & I want to convert it to a Double 53/39. Can anyone tell me if this is difficult to do & how much would it cost?

Thanks,
Cormac

Comments

  • Monty Dog
    Monty Dog Posts: 20,614
    It'll cost you the price of two chainrings! You'll need 110mm PCD chainrings to fit your compact spider and prices can vary from a tenner to £40+ per chainring. Another option would be to fit a cassette with a smaller sprocket e.g. 11 tooth - a 50x11 gearing ratio is higher than 53x12.
    Make mine an Italian, with Campagnolo on the side..
  • maddog 2
    maddog 2 Posts: 8,114
    or just flog the compact c/set, buy a std double c/set, and raise the f.mech a tad.

    Most people tend to go the other way, so std doubles come up cheap these days.

    you may also need more links in your chain (or a new chain) .
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • Evil Laugh
    Evil Laugh Posts: 1,412
    Aye you'll get good money for a compact ultegra chainset on ebay, probably enough to buy a new double somewhere else if you do your homework.
  • NWLondoner
    NWLondoner Posts: 2,047
    Sorry to hijack the thread but i have a similar question.

    I currently ride a 50/34 with 12/27. I have a FSA Gossamer MegaExo Compact Chainset. My wheels are Shimano 10 speed only.

    95% of my cycling is on the 50. I only drop onto the 34 when going up a either long drag hill or short steep hill.


    Is there anyway i could change to a double but still have a get out of jail gear for the above situations? or is MTFU the only option on the double :wink:
  • Cormac
    Cormac Posts: 18
    I don't mind spending a few bob to do it if I have to, as I feel I'm just spinning the legs sometimes and I've a bit more in the legs. I've got 28-11 cassette and I think the jumps are too big.
  • maddog 2
    maddog 2 Posts: 8,114
    90rpm on 50-11 is 32 mph

    90rpm on 53-12 is 31.1 mph

    If you're currently spinning out then maybe you need to spin faster :wink: (or turn pro). What's your current ave. cadence?

    NWLondoner - you could fit a 52 ring but to maintain decent fron shifting you don't really want to go to more than 16t diffrence, so you'd need a 36t small ring really. In other words, you can't have everything :wink: but you can usually find a reasonable balance for your style and the roads you ride.
    Facts are meaningless, you can use facts to prove anything that's remotely true! - Homer
  • Cormac
    Cormac Posts: 18
    I've been racing quite a bit this year and when I'm in a group powering along I feel I've a bit more in the legs. In a recent race I did a 75km race and my avg cadence was 92 rpm. My avg. speed was a bit slow; 31km per hr, but there was an absolutely savage head wind for the first 50km. I'm far from pro!
  • sheffsimon
    sheffsimon Posts: 1,282
    NWLondoner wrote:
    Sorry to hijack the thread but i have a similar question.

    I currently ride a 50/34 with 12/27. I have a FSA Gossamer MegaExo Compact Chainset. My wheels are Shimano 10 speed only.

    95% of my cycling is on the 50. I only drop onto the 34 when going up a either long drag hill or short steep hill.


    Is there anyway i could change to a double but still have a get out of jail gear for the above situations? or is MTFU the only option on the double :wink:

    You will still have the 27 sprocket, and with the 39 on the front, what hill cant you ride up with that?? Your legs will be spinning like crazeeee :wink:

    Short steep hills, leave it in the big ring and nail it, like us 'ard northern types. :)
  • dennisn
    dennisn Posts: 10,601
    Money wise I'm with Monty Dog. All you really need to do is buy new chain rings. No need for a new crankset.

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