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  1. #1
    Retired dabbler hobkirk's Avatar
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    2007 Specialized Roubaix Elite Triple - 1st ride = century 9/19/2010 * * 2007 GT Carbon Series 2, Ultegra - 7/2010 - 2,000 miles, (replaced 'cuz it was too small) * * 1975 Lotus Odyssey - resurrected & ridden 400 miles to "try out" cycling
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    What else needs changing/adjusting after swappin 53/39 crankset for a 50/34 crankset?

    I'm replacing my 35 year old Lotus with a triple and 7 speeds with a 2007 GT GTR Series 2 (CF, Ultegra except 105 brakes and FAS crank). I replaced the upgraded SRAM Force 53/39 crank set with the original FAS 50/34 crank. It's not as precise, especially shifting the front derailleur. I can take it to my LBS, but I need to know this stuff AND I'd like to ride it in two group rides this weekend (I just started this month but I've been doing 60-70 miles a weekend).

    I've only ridden it a few miles. I have to sort of force the brifter extra hard to get it to climb from the small chain ring to the big one. And there's some clickety-click interference sounds in certain gear combinations.

    1. Do i need to remove link(s)?
    2. Does the front derailleur need to be lowered?
    3. Is there a great road bike how-to web site?


    Here are pictures (I wish I knew how to get them inserted full size) -
    P1030930..jpg
    Rear derailleur forward
    P1030932..jpg
    Rear derailleur back
    P1030934..jpg

    Thanks

  2. #2
    Senior Member
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    The front derailleur is much too high. See www.parktool.com for instructions for setting up derailleurs. You will need to start over, do all of the steps in sequence leaving nothing out.

    Edit: the chain is too long. There should be no slack in the chain when on the smallest cog and smallest chainring. It appears from the last picture that the derailleur has "bottomed out" and there is no tension on the chain. You may need to remove 1" of chain. There are many sources for chain sizing instructions. Be sure to use the correct procedure for joining the chain, usually requires a special pin.
    Last edited by Al1943; 06-25-10 at 03:47 PM.

  3. #3
    I was poisoned! dstrong's Avatar
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    Al1943 is right about derailleur height and Park Tool instructions providing the proper method. It appears you'll need to re-size your chain and probably have to take out a link or two.

    2003 Interloc Impala2003 Interloc Impala2007 ParkPre Image C62003 Interloc Impala2004 Specialized Rockhopper

  4. #4
    Retired dabbler hobkirk's Avatar
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    2007 Specialized Roubaix Elite Triple - 1st ride = century 9/19/2010 * * 2007 GT Carbon Series 2, Ultegra - 7/2010 - 2,000 miles, (replaced 'cuz it was too small) * * 1975 Lotus Odyssey - resurrected & ridden 400 miles to "try out" cycling
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    After further contemplation, I realize that I am almost surely going to need to change the rear cassette to 11-28. I think 80+ miles of "rolling hills" this weekend will make that very clear.

    Thanks for the Park Tool repair info suggestion - it looks pretty good.

  5. #5
    DRF aka Thrifty Bill wrk101's Avatar
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    Quote Originally Posted by hobkirk View Post
    After further contemplation, I realize that I am almost surely going to need to change the rear cassette to 11-28. I think 80+ miles of "rolling hills" this weekend will make that very clear.

    Thanks for the Park Tool repair info suggestion - it looks pretty good.
    With the compact double up front and a 11/28 cassette in back, you need to check the capacity of that rear derailleur. You may need a longer cage to handle it (need 33 tooth capacity). Depends which era Ultegra and which model you are using.


    +10 Park Tool site will guide you through the process.
    Last edited by wrk101; 06-25-10 at 08:46 PM.

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