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  1. #1
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    New question here. Will a FT70 cartridge fit in a 1997 P-Bone D Headshok?

    I mean, it might fit, but will it be functional? I really need a coffee table book of the entire Headshok family with exploded, labeled diagrams.

    andy b.

  2. #2
    Eff U Gee Em
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    I don't believe they're compatible. IIRC the P-Bones were 50-60mm carts and the Fatty was 70; it might "fit" but I suspect you would damage the cart during compression.

    Edit:

    Belay that, the more I think about it, I suspect the requisite diameters and threads are the same but I don't think it *would* fit due to the length of the air cartridge or spring stack (depending on which version), but if it did I suppose it would work, though you would only get at most 60mm out of it.

    If you're looking for more travel the Fatty/Ultra Fatty had 70mm and the SuperFatty had 80mm.
    Last edited by howdyhowdyhowdy; 09-16-2010 at 06:49 PM.

  3. #3
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    Thanks. I guess one thing I was wondering was the P-Bone D doesn't have an air-adjustable feature, and I think the FT70 might. If I look up inside the forks under the headset, the fork is solid. I didn't know if the FT70 cartridge has a valve sticking out of the bottom to adjust the air pressure. If the FT70 does, then I don't see how it would fit into the PBD.

    I do have one other question though. When I look at the Headshoks, they all look like they are the same size externally, and they all have the same 88 bearings to ride on. Shouldn't they all be the same size internally as well?

    andy b.

  4. #4
    Eff U Gee Em
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    The P-Bone was coil/MCU only. The solid piece you refer to is just a support for the bottom of the spring; it is removeable. The Fatties of that vintage were available in 2 versions that I can recall: Fatty D which had a coil spring and lockout that also utilized the spring support from above, and the Fatty SL which had a 5-position rebound damping dial and an air spring with an air valve the was accessible by removing the wheel. I don't remember what the other internal code was for the Fatty carts, so I'm not sure if the FT70 is the "SL" or "D" cart.

    If you measure the distance from the bottom edge of the lower headset cup to the top of the fork crown where the square steerer is pressed in you will find that the 2 forks are different (you would need to lift up the bottom of the fork boot for this- or just "feel" it). This is what limits the P-Bone to 60, the Fatty to 70, and allows the SuperFatty to go to 80, thought the cartridges may have some effect on this also- it's been a loooong time since I've been in a Headshok. Longer distance = more internal volume = longer cartridge, therefore more travel.

    BTW, if you remove the cartridges from both forks, I'm pretty sure the Fatty is lighter than the P-Bone. And it looks waaay cooler.

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