How to Change to Compact Crank

Discussion in 'Road Bikes' started by dirdick, Aug 3, 2010.

  1. dirdick

    dirdick Junior Member

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    I've got a Giant OCR-2 triple and want to change over to a compact crank 50/34 but am not sure what bottom bracket and crankset combo will work for a reasonable price. I went to the LBS yesterday and they told me to buy a new bike. So, can someone help me out on what will work??
     
  2. Industry_Hack

    Industry_Hack Total noob (& forum admin) Admin Staff Tavern Member

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    Go back to that LBS and ask them for the name of a good shop to buy a new bike from. ;)

    Does your bike come in a compact version? If so, check the specs for the BB on that model.
     

  3. dirdick

    dirdick Junior Member

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    The bike seems to always be a triple, so I guess the starting pt is the bottom bracket??? Online search gives says that that particular year OCR-2 has a BB-7420, but, I'm not sure what that means exactly. I also don't know anyone who has gone over to the compact crankset - I guess I can go to one of the bike shops in a nearby town (22 mi away) where the people are a little nicer. (The LBS was taken over by the owner's grandson so that may be part of the attitude issue ... )
     
  4. Industry_Hack

    Industry_Hack Total noob (& forum admin) Admin Staff Tavern Member

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    For this one, it would be worthwhile to speak with a knowledgeable shop.
     
  5. flanderscycling

    flanderscycling New Member

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    What's wrong with the triple?
     
  6. BlazingPedals

    BlazingPedals Member

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    To me, compacts are nothing but a marketing ploy for people who need a lower gear than a road double offers but are too vain to install a triple or a wider-range cassette. Or, in the other direction, you really, really need to save 30 grams and are willing to give up two low gears and a high gear to do it.

    But... if you've got your heart set on it, why not get a new 2-piece, external-BB set? Then you won't have to worry about matching the BB because it's included.
     
  7. flanderscycling

    flanderscycling New Member

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    That's why i asked what could be wrong with it?
     
  8. Burr

    Burr Cranking Old Guy

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    Why do you want a shorter crank?
    I have a triple with long cranks that will hit when I power though a corner. I also have a triple with a Bio Ring on my touring bike for those wonderful long climbs on California 101!!!

    Sounds like you need someone to setup your bike.

    My .02 cents
     
  9. retromike3

    retromike3 retromike3

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    compact and triple

    What I did was to get a compact(94 mm bolt) triple and put it on my road bike. I have a new' but old spaced eight speed rear hub with a 12-32 rear cog set up and a 22-32-46 front chainrings. This gives me a low gear of about 16 inches and a high gear of over a hundred and three inches. I have been climbing some really steep hills lately and its nice to have a "bail out" chainring to drop into because its easer to ride the right low gear than walk the bike up the hill.

    last time I did that ride I did it with the 32-26

    I was using a 35-52 double with a 12-26 cassette but it was not low enough to get my feeble self up those grades lately.

    I really like the ramps and pins in the new chain rings because they make shifting so much easier. The rear derailleur is a SACHS New Success made by Campy but set up with Shimano spacing, B.I.T.D. nobody had a eight speed indexed drive train so SACHs commissioned Campy to design and make there new system. I still have the original New Successes front derailleur but I have replaced it with a newer "C" braze-on derailleur because its a better fit for my smaller inner chainrings.

    Mike
     

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    Last edited: Aug 7, 2010
  10. Burr

    Burr Cranking Old Guy

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    How much of the year can you ride over there?

    Do you own a bike shop?

    Would you please fill in your profile?

    Thanks
     
  11. flanderscycling

    flanderscycling New Member

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    you can ride almost the whole year, if you don't mind the rain from time to time.

    We have rarely hard winters, most of the time, the temperature between november and february is higher than 30°F, sometimes, in january-february we have some winters with snow and ice and temperatures below zero.

    And no, I don't have a bike shop, I'm just an addict since my youth :cool::cool:
     
  12. Burr

    Burr Cranking Old Guy

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    Thanks for the reply.