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  1. #1
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    HA vs. fork offset / trail ?

    I am going to run 650b F & R on my Turner RFX that has a 68* HA. The fork is a RS Pike, guessing it has a 38mm fork offset ??? Reading on the 29er forum that 29er forks have more offset to handle the larger wheel diameter. What offset would work best for a 650b ?

  2. #2
    www.derbyrims.com
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    I'm just a student of this. There are some expert 650b bike builders in the Frames forum, who could give a more accurate answer.

    Theoretically, if you could adjust your frame so your BB and handlebar height didn't change going to 650b, then adding a few mm more offset, about 4 or 5mm, would maintain the same trail and virtually the same steering flop feel.

    However, converting a 26'er frame and fork to 650b raises the BB and handlebars, so the 1/2 inch higher center of gravity becomes a little less stable. But using the same fork with a 1/2 inch increased radius 650b wheel, with 650b also in back, increases trail about 3 or 4mm and adds directional stability but not noticeably more steering flop. The stand over is 1/2 inch less.

    I feel after converting my 5.5 inch travel bike to 650b that there is very little handling balance difference converting a 26 bike to 650b at both ends, except the bike feels bigger, smoother, and in my opinion a little more stable handling overall at any speed, even when climbing or riding very slow switchbacks.

    Everyone's reaction is a little different. Very few, only one that I recall, have posted they didn't like it. To me as a larger rider at 6'1 converting to 650b was a 100% upgrade with no downsides.

  3. #3
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    I originally tried a 650b front only. The steering fely lazy, vague, floppy. I decided to build a rear as well (waiting on my LBS). I thought if the rear doesn't provide good results maybe a 29er fork w/ more offset would ??? Thanks

  4. #4
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    If I may, from gt at the 29er forum and Lennard my old friend from Boulder.
    http://velonews.com/article/7322
    http://g-tedproductions.blogspot.com...angle-for.html

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