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  1. #1
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    2 x 9 conversion?


    How do you or can you convert a regualr 3 x 9 gear ration to a 2 x 9 gear ratio. Can you just take off the small chain ring, or do you have to buy a certain type of cranks/rings? Also the same Q with the front der.
    thanks
    JF2 Racing!

  2. #2
    information leafblower
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    relevant article

    There's a good article on light bikes...www.light-bikes.com

    Basically the things to watch are chainline - tunable with BB, and front mech throw - again tunable with the stop adjust screws. Now unless you like pushing big gears uphill you might also want to go to a smaller (29 or similar) middle ring...these aren't too common so you might need to go custom (try booneti for exotica).

  3. #3
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    ok, thanks!
    JF2 Racing!

  4. #4
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    Works ok for ME!

    Hey
    Made the switch about 2 months ago and I find it much better. Just did it on the cheap and took my small ring off and got a Cannondale 29t to replace the middle ring. ( I had 5 arm cranks 94BCD). Adjusted the limits on Front derailor and it seems to work fine. I had a 11-34 on the back so I still have an easy gear!! If I went to a narrower BB I would probably get more life from my drivetrain.

    I am a roadie so just having the two gears up front means I don't have think quite so much.

    Hope it helps
    Grant

  5. #5
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    sweet

    ok- thanks a lot for that review on it. so just get like a 29T ring replacing the middle and small ring....maybe a narrower bb...awsome..my gears in the back are 12-34 so i think i will be fine...right??

    i think that i am going to invest...sooner or later in some of those really cheap ritchey grip shifts.....aren't they just sachs though??

    also i am looking in to getting some new levers to replace my sd7's....any affordable light ones??\\

    thanks for your comments in advance
    JF2 Racing!

  6. #6
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    oh wait-
    one more question---would it make any real noticable diff from the 29t to like a 28t or a 30t??

    thanks
    JF2 Racing!

  7. #7
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    Quote Originally Posted by I Like Bikes
    oh wait-
    one more question---would it make any real noticable diff from the 29t to like a 28t or a 30t??

    thanks
    Not overly sure, but i know that I wouln't go down to 28t and had been thinking that in the future I would probably get a 30t instead of the 29t. Just means that the gears are a bit closer when I drop down from the big ring.

    Grant

  8. #8
    Nouveau Retrogrouch SuperModerator
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    I ran a 2x7 for years with a 45/28 up front and a 12-34 rear. Worked great.
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  9. #9
    Are you talking to me?
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    say that again?

    Quote Originally Posted by shiggy
    I ran a 2x7 for years with a 45/28 up front and a 12-34 rear. Worked great.
    A 7sp 12-34? not. Were you only using 7sp on a 9sp cassette? Is there a 34t 7sp? Megarange, or what?
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  10. #10
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    Back in the old days shimano had a 13-34 7s cassette as part of the regular lineup at the HG 50, 70, and 90 levels of cassettes. The cogs were 13, 15, 18, 21, 25, 29, 34 (so a 2T, 3T, 3T, 4T, 4T and 5T jumps). These were not mega-range cassettes and indeed predated the whole megarange gimmick by a decade.

    Prior to suntour inventing microdrive, it was normal to find cassettes and freewheels with up to a 38T granny cog. Most XC racers in the late 80s/early 90s ran a 12-28 cassette and 24/36/46 chainrings.
    I don't post to generate business for myself or make like I'm better than sliced bread

  11. #11
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    I use a 29t with a 12-27 cassette and the closer ratio is much better than 12-32 or 12-34.and if you use a Dura ace you can save weight.haven't used a DA since the prices went out of site, though.

    I don't think a 28t exsists. call FSA for 29t ring. they're not listed on their web site but I got them by calling.

    I use a road BB.

  12. #12
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    ok...

    so just get a 29t and leave my regular 12-34 cassette? and i am going to upgrade the cassette soon, what size and brand would be good for the 2 x 9?
    thanks guys
    JF2 Racing!

  13. #13
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by damion
    A 7sp 12-34? not. Were you only using 7sp on a 9sp cassette? Is there a 34t 7sp? Megarange, or what?
    SunTour Winner Pro freewheels. I still have a bunch and a box of cogs to make pretty much any combos I want. There was a time when you could customize the gearing on the rear end.

    Heck, I have a 6-speed FW with a 36t cog (or is it a 38T?)


    I did not even own a cassette hub until 3 years ago.
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  14. #14
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by dang
    ...I don't think a 28t exsists...
    It does if you use a 28t granny ring and put the big ring in the middle position.
    mtbtires.com
    The trouble with common sense is it is no longer common

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