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  1. #1
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    Shimano 2300 triple to double questions

    My wife's CX bike came with a Shimano 2300 triple setup, but she never uses the granny ring when racing. I just ordered a compact double crank to shave weight and slightly lower the gearing relative to the triple's middle ring. The big question is whether I'm OK locking out the granny position on the shifter with the front derailleur limit screw MTB style or do I need to find a double shifter.
    I am also thinking of going to an 11-28 cassette to give her a better climbing gear for training rides. I have not done a detailed calculation but I'm guessing that the medium cage rear derailleur from the triple setup has more than enough capacity and I might be able to run a 30T rear for a SRAM Apex style setup. I'm looking for your experience and insights.

  2. #2
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    It would be best to change the front derailleur when changing the crank. The differently shaped cage on a double specific der. will work better for her. When you adjust the limit screws, you will be "locking out" the large ring position, not the granny. Make sure your wife knows not to "double" shift if there is any issues with getting to the big ring. If the cable goes slack (as they do over time), she may feel the need to hit the shifter again. Trying to force the shifter into the third position, with the der. limited, you can possibly bind the shifter ratchet mechanism. Sometimes they literally lock up for good. Pushing the shift lever and holding it until it completes the shift should keep her from ever wanting to shift into third position.

    As far as the rear der, on most bikes a Shimano der. has a tough time even working with their suggested largest cog of 27 or 28 (depending on model). You definitely won't be able to stuff a 30 on there without the upper pulley wheel interfering with the largest cog.

    Try the compact first and see.....

  3. #3
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    I would get some ST-R500 shifters along with a double crank and FD.
    Shimano ST-R500 8 Speed STI Shifter Set at JensonUSA.com

    Don't think a med cage will work with a 30T cog.

  4. #4
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    You can use the triple shifter on a double crank. The cable throw for the outer two rings is the same on a double and a triple.

    I agree about using a double derialleur though. It'll up shift better than the triple one.

  5. #5
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    Thanks for the info, this is a budget bike so we are going one piece at a time. When she is actually racing she doesn't shift the front so we can accept some shift quality issues as long as the rear shifts OK. We'll go for a cheap 11-28 cassette, and if I run into clearance issues I can install a Deore M510 MTB derailleur I have lying around. Down the road, I can get some used 9 speed shifters and derailleurs. I will update this thread at some point since I think cheapskate builds deserve more attention.
    Last edited by SlowJoeCrow; 10-19-2011 at 04:33 PM.

  6. #6
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    I don't think this is going to achieve what you want. You say that she doesn't shift the front during races, but going to a compact with a 34T is going to require her to shift the front quite a bit during a race, as 34x11 will be a useless gear, while the 50T ring is going to be too large, even with a 32 rear cog. What would work better is to swap the 30/42/52 triple to either a 30/39/50 triple, or a 38/48 cyclocross double.

  7. #7
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    Quote Originally Posted by redlude97 View Post
    I don't think this is going to achieve what you want. You say that she doesn't shift the front during races, but going to a compact with a 34T is going to require her to shift the front quite a bit during a race, as 34x11 will be a useless gear, while the 50T ring is going to be too large, even with a 32 rear cog. What would work better is to swap the 30/42/52 triple to either a 30/39/50 triple, or a 38/48 cyclocross double.
    Most cross doubles are 46/36 are they not? At least mine is.....

  8. #8
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    Quote Originally Posted by redlude97 View Post
    I don't think this is going to achieve what you want. You say that she doesn't shift the front during races, but going to a compact with a 34T is going to require her to shift the front quite a bit during a race, as 34x11 will be a useless gear, while the 50T ring is going to be too large, even with a 32 rear cog. What would work better is to swap the 30/42/52 triple to either a 30/39/50 triple, or a 38/48 cyclocross double.
    The current setup is a 30/39/50 and the crank we bought is a 36/50 so it should work out fine. I can always get a 46 or 48 outer ring if she starts to need bigger gears. Most of the beginner class bikes we see are running 36/46 cranks so this gets the gearing into the mainstream. The hard part was finding a compact crank with 170mm arms for less than $100. Everything else can be easily done with used or closeout parts.

  9. #9
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    The operation was a success. The crank bolted up just fine and after lowering the front derailleur and tweaking the cable a bit I got smooth running and shifting on the 36-50 crank and 14-28 cassette. The only minor kludge at the moment is the need to trim shift in the small chainring but my wife was very pleased with setup after her first CX race on it today.

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