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  1. #1
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    650B front wheel in 26" fork assuming rear fits 650B also. increased trail = what?

    Assuming you fit 650B wheels on your 26" mtb both front and rear, What does the increased trail resulting from a 650B wheel in a 26" fork do? Does it increase stability? Opposite? Anything else?

    In addition to 650B forks being taller with taller axle to crown measurements, what are the manufacturers doing with regards to trail? Are they changing the offset?

  2. #2
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    The change in trail is going to make the bike feel like it has a slacker head angle. With a 650b frame you can adjust the head angle to compensate, or you can use a different offset on the fork.
    2012 On One Whippet 650b
    2012 Santa Cruz TRc 650b
    2014 On One Dirty Disco
    2010 Soma Groove
    1987 Haro RS1

  3. #3
    NedwannaB
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    Depends

    Quote Originally Posted by morkys View Post
    In addition to 650B forks being taller with taller axle to crown measurements, what are the manufacturers doing with regards to trail? Are they changing the offset?
    Are you talking them designing different 650 fork because going on 26" frame??

    As far as bike handling changes with 650's on, with my conversions anyway, I noticed a better stability feeling overall but not as precise on the carving super tight stuff. Not enuff to consider a neg. Maybe that's just the increased bb height but I've come to compensate for it as I'm not an aggressive carver anyway. The overall benifits outweight for me anyway.
    Wait,who did he tell you that?....

  4. #4
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    True 650B forks are getting bigger offsets. My Fox 26" fork has a 39mm offset. An X-Fusion Velvet (almost a Hybrid fork really) has a 41mm offset. My White Bros. 650 Loop has a 45mm offset. I think the new Fox 650B fork has a 44mm offset.

    I'm NO expert on this but here is what I noticed going from my converted Prophet with 26" fork and 650 wheel to my Jamis Dakar with the Loop fork. Both bikes have the same 69 degree HA. The Prophet a straight 1.125 steerer tube and 9mm thru axle. The Jamis has a tapered fork and 15mm thru axle. Both with the same 2.3" Neo Moto tire. 6mm greater fork offset on the Jamis.

    Night and day difference in steering control. Where the Prophet is twitchey and wandery the Jamis tracks straighter, more precise and easier to control. It's almost like all the motions got slowed down and you can relax much more and is less tiring. It's been an awesome improvement. Now I know the Jamis has the taper fork and 15mm axle but I'm figuring that 6mm offset has a great deal to do with it as well and at least for me a good thing. I ride in really rocky technical trails. My totally non expert take on it.
    2013 Banshee Spitfire V2 650b

  5. #5
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    This is useful:

    http://www.mountainracingproducts.co...IST-Sheet1.pdf

    What does Offset 1.125 and Offset 1.5 mean? Is that referring to the tapered 1.125 to 1.5 headset? Why would there be more offset with a 1.5?

    If anybody is interested, SRAM replied to an email inquirey of mine:

    Rockshox Rev 650

    Offset 42 mm
    120 mm travel fork axle to crown is 509 mm
    100 mm travel fork a to c is 489 mm,

    I think it's safe to say the a to c for a 140 mm Rev 650 would be 529 mm but I am not sure.
    Last edited by morkys; 11-12-2012 at 08:52 AM.

  6. #6
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    Is the increase offset of the Fox f32 650b fork (44 mm) vs. 26" version (39mm offset) noticeable? Is the increase offset in the lowers (ie dropouts) or does the Fox 650 fork use a different steerer crown with the increased offset?

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