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  1. #1
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    [ask] SGS / long cage deraileur and 12-25 cassette compatibility..

    helo..

    is it possible to combining 12-25 cassette with shimano long cage /SGS derailleur...
    my hardtail bike is installed with shimano ultegra 6700 groupset..
    then i change to flat bar, and also change my shifter with shimano xt dyna sis 10 sp
    because to find 10 sp flatbar shifter here is very difficult, beside the price is remarkably high......

    and yes of course there is this problem, the shifting is jumping about 2-3 cog...
    some of the mechanics suggest, i should use dyna sis rear derailleur to eliminate this problem..
    i intended to have one , but many of the store here only have long cage / sgs derailleur....

    really need all of your suggestion...
    because i am newbie, and started cycling for 5 month....

    thx before for your help

  2. #2
    biked well well biked's Avatar
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    Quote Originally Posted by raspberri View Post
    helo..

    is it possible to combining 12-25 cassette with shimano long cage /SGS derailleur...
    my hardtail bike is installed with shimano ultegra 6700 groupset..
    then i change to flat bar, and also change my shifter with shimano xt dyna sis 10 sp
    because to find 10 sp flatbar shifter here is very difficult, beside the price is remarkably high......

    and yes of course there is this problem, the shifting is jumping about 2-3 cog...
    some of the mechanics suggest, i should use dyna sis rear derailleur to eliminate this problem..

    i intended to have one , but many of the store here only have long cage / sgs derailleur....

    really need all of your suggestion...
    because i am newbie, and started cycling for 5 month....

    thx before for your help
    If I am understanding your situation correctly, you had an Ultegra group on the bike, including the shifters and the rear derailleur, and now you have gone to the new Dyna Sys 10 speed mountain bike shifters, but your rear derailleur is still Ultegra. The shifting is not good, the mechanics have recommended a Dyna Sys 10 speed rear derailleur to solve the problem.

    If this is the case, then the mechanics are correct. It's a simple case of cable pull ratio: the new Dyna Sys shifters you are using pull a different amount of cable than your Ultegra shifters did for each shift, and therefore you Ultegra rear derailleur will not work correctly. The Dyna Sys rear derailleur will work correctly with your Dyna Sys shifters, because it is designed to work with this new cable pull ratio Shimano is using for the Dyna Sys group(s). As for cage length, the SGS derailleur will work fine, the cage length simply determines how much chain slack the derailleur can take up. The SGS model can take up the most slack because of its very long cage, and it has a lot more chain wrap capacity than your drivetrain requires, but that's okay, it will work just fine.

  3. #3
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    Quote Originally Posted by well biked View Post
    If I am understanding your situation correctly, you had an Ultegra group on the bike, including the shifters and the rear derailleur, and now you have gone to the new Dyna Sys 10 speed mountain bike shifters, but your rear derailleur is still Ultegra. The shifting is not good, the mechanics have recommended a Dyna Sys 10 speed rear derailleur to solve the problem.

    If this is the case, then the mechanics are correct. It's a simple case of cable pull ratio: the new Dyna Sys shifters you are using pull a different amount of cable than your Ultegra shifters did for each shift, and therefore you Ultegra rear derailleur will not work correctly. The Dyna Sys rear derailleur will work correctly with your Dyna Sys shifters, because it is designed to work with this new cable pull ratio Shimano is using for the Dyna Sys group(s). As for cage length, the SGS derailleur will work fine, the cage length simply determines how much chain slack the derailleur can take up. The SGS model can take up the most slack because of its very long cage, and it has a lot more chain wrap capacity than your drivetrain requires, but that's okay, it will work just fine.
    thank you for the response sir...
    iam sorry my english is not good....
    you mean is i should just replacing my ultegra derailleur, with dyna sis derailleur ( in this case SGS/long cage deraileur)
    and that SGS derailleur would work well with my 12-25T ultegra cassette...?
    also not necessary to replace any other parts, just the derailleur yes....?

  4. #4
    biked well well biked's Avatar
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    Quote Originally Posted by raspberri View Post
    thank you for the response sir...
    iam sorry my english is not good....
    you mean is i should just replacing my ultegra derailleur, with dyna sis derailleur ( in this case SGS/long cage deraileur)
    and that SGS derailleur would work well with my 12-25T ultegra cassette...?
    also not necessary to replace any other parts, just the derailleur yes....?
    Well, honestly, I'm not exactly sure what all you have changed out on the bike. You refer to it as a "hardtail," which would imply that it's a mountain bike, but yet it had an Ultegra group on it, which would imply that it's a road bike. Since you say you switched to a flat bar, I'll assume that it's probably a road bike you've converted to a flat bar bike. If that's the case, I would hope that you are using brake levers that are compatible with your brake calipers (again, a possible cable pull ratio issue), and that the new flat bar front shifter shifts well with your "road" front derailleur (again, a possible cable pull ratio problem). But since you haven't mentioned any brake or front shifting problems, I'll take it those items are satisfactory. If that's the case, then yes, just change the rear derailleur to the SGS Dyna Sys model, and you should be set. What's happening now is the Dyna Sys shifter is pulling more cable per shift than the Ultegra rear derailleur is designed for, and it's shifting 2-3 cogs at a time, as you say in your original post. The Dyna Sys rear derailleur should solve this problem. And again, don't worry about the SGS vs. GS issue, the longer cage SGS will work fine-

    P.S. Oh, and don't worry about your English. English is my first and only language and sometimes I don't communicate with it very well, either. I've traveled overseas enough, where I have little or no understanding of the native language being spoken around me, to have great appreciation for anyone who has come anywhere close to mastering more than one language.
    Last edited by well biked; 01-09-11 at 11:49 AM.

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    weel thank you again for your very helpfull information....
    my "hardtail" is really hardtail mountain bike with road ultegra groupset and a dropbar, intended use for training and commuting, because it's still rainy every day here....
    and since mtb geometry and tire not as big as road bike, and i can use bigger tire size which is easy to inflate with my small hand pump ahhahah....
    i'm just using single 50T chainring, and MTB hydraulic brakes, they work just fine, except that derailleur....
    oh, my new settings is cut about 500gr for the weight though...my bike is 7.7kg total now...
    maybe is should try single speed to cut more weight.....hehehe

    okay then, i should get that SGS derailleur before this evening...
    thank you again sir, it's really nice to know a very helpfull person when you got in any trouble.....
    Last edited by raspberri; 01-09-11 at 10:13 PM.

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