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  1. #1
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    HD head angle question

    What is the head angle for the HD 160 with a A) talas in 160mm mode B)talas in 120mm mode?

    Just got the talas for my HD and really enjoy how comfortably the bike climbs in 120 mode. Still, in my never ending quest for the ultimate ass hole bike, I'm considering a -1 angleset. I figure that in 120 mode, it'll still climb better than it used to in 160 mode and in 160 mode it'll really rip on the DH! Anyone know the exact numbers?

    Thanks, Circles
    Last edited by circlesuponcircles; 05-06-2013 at 09:04 AM. Reason: mistake

  2. #2
    www.derbyrims.com
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    There is close to 1 degree frame angle change with each 20mm change in head tube height.

    From ibis published angles of the HD160 with 160mm fork 67/71 frame angles, then the same fork lowered 20mm is close to 68/72 degrees, shifting your seated rider weight forward about 10mm. The easier climbing power with the lower fork travel is mainly from that rider weight shift forward. The steeper fork angle is slightly quicker to maintain balance at low climbing speed.

    I've found climbing very steep with a 160 travel fork with a remote dropper post lowering the seat about 1 inch climbs easier for short distances. The lowered seat also moves seated weight forward over the cranks and keeps the front wheel from lifting easily. For longer climbs lowering the fork and maintaining full leg reach is better for shifting seated weight forward.

  3. #3
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    Thanks Derby! Interesting, I tend to dop my seat about an inch for short/steep/techy climbs also. I always thought that it helped me move the my weight for and aft while out of the saddle. Didn't think about the fact that it moved my center of mass forward, too.

    From what your saying, it seems that, now that I have the talas, I could really get away with a -1 angleset. For climbing (120mode), I'd have an HA of about 68 and for descending (160mode), I'd have an HA of about 66. In theory, both should be better than the fixed HA of 67 with my old float. The only place i might suffer would be cross country style trails. Luckily I rarely ride that sort of thing.....

  4. #4
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    Got any idea how much the -1 angleset will affect BB height and wheelbase? I seem to have left my protractor in 9th grade geometry class. Along with my math skills....

  5. #5
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    Try this tool:

    geometryCalc

    +10.7mm on WB, -1.7mm on BB on a XL
    Any sufficiently advanced technology is indistinguishable from magic
    - Arthur C. Clarke

  6. #6
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    Wow! That's awesome!

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