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  1. #1
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    Ideal 650B Frame Geometries

    I plan to build a 650b Hardtail during my Cromoly Brazing class at UBI next month. This will be my first frame build, but will be quite supervised.
    I'm planning on using the RS Pike (110-140 travel), for a front suspension, and running it mostly in it's 110 setting, only ramping up the travel for gnarly descents.
    I'm trying to gather any advice on angles and tube lengths that will help make this bike a great all-around trail bike.
    Thanks!

  2. #2
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    I'll try:

    73 degree ST angle, 70 degree HT angle with fork in 110mm mode, 16.9" chainstays, 12.5" bottom bracket and whatever seat tube length and top tube length make sense for you.

    With each incremental change in travel both your ST angle and HT angle will slacken out a bit for descending the gnar. The bottom bracket height will allow good pedal clearance for the same gnar (rocks and logs and roots and crap) but won't be too high as to make the bike feel outta whack.

    How's that sound?

  3. #3
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    That sounds fantastic, and is exactly the sort of information I'm looking for. Thanks!

  4. #4
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    YOu are welcome - but I'd also suggest asking around in the frame builders forum.

  5. #5
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    My $0.02

    I would make the bottom bracket 12" with the fork at 110. The Bottom Bracket will go up with the fork about 1/2" with a 30 mm increase in fork. That would make it 13" which can get a little twitchy. Unless you are into "East Coast" geometry and ingnore me.

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