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  1. #1
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    Help! I Think I Bent My Sturgis Bullet

    I have a 19" 2014 Motobecane Sturgis Bullet.
    I installed a 490mm Carver Popeye rigid fork. The head angle, based on a digital level, was right about 68*. I even checked the floor first to make sure I had a level reference. I'd say the measurement is probably good within a 1/2*.
    I recently crashed into a tree very hard.
    The right leg on the fork was crushed, but I was able to ride slowly back to my truck.
    Carver sent me out a new fork and I installed it. The new fork appears to be exactly the same in every aspect. The head angle now measures more like 68.5*, but def. not 69*. Big deal, right?
    Well now I cannot ride the bike no-handed. The bike wants to flop to the side and go in a circle. Previously, it was the model of stability, whether running fats or +.
    (Part of me is saying "Well maybe it was always like that and you never noticed")
    I put a straight edge on the top of the top tube, and on the bottom of the downtube, and neither appears to have any sort of kink or buckling. HOWEVER, the area right behind the head tube is the large junction of hydroformed tubes where a kink could go undetected.

    Anybody have any suggestions on how to detect a problem? I am at a loss. I am pretty sure there is something wrong, but I can't find it. Anyone else have a 19" Sturgis to compare some dimensions? What dimensions? ...I'm not sure. I would feel bad about scrapping this frame without really knowing that it is actually damaged.

    BTW - the alignment between hubs, seatpost, handlebar stem, and front wheel seems to be dead straight, but I have yet to actually gauge it with the park frame tool.

    Thanks,
    -F
    It's never easier - you just go faster.

  2. #2
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    Is the offset on the new fork the same as the old? It might be the same height fork, but with a different offset resulting in different trail with different handling.

    If you crashed in to a tree, then the force would be pushing the fork backwards, and if it bent the frame as a result, wouldn't the head angle get steeper instead of slacker. If you'd done a big drop to flat and bent the fork out, then I could see this bending the frame this way, but not with an impact.
    I would advise not taking my advice.

  3. #3
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    Did you replace/inspect the headset?

  4. #4
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    Avoid trees.

  5. #5
    Rippin da fAt
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    George, George of the jungle, watch out for that tree!!!

    If the rake/trail of the fork differs, this will affect caster angle significantly resulting in the chopper like feel.
    Is there a lbs that can check the frame alignment? Not many are equipped for it, but just curious. Likely there is no frame damage as it sounds like your fork took the damage.
    Get fAt, Stay fAt, Ride fAt
    Doctor recommended...

  6. #6
    Professional Crastinator
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    Thanks for the responses. They are helping me think.

    My gut says the head angle is ever so slightly steeper. By such a small amount as to not matter. I mean, I think I can influence HA more by using different tires. But still, it feels weird.
    Here are some pix. I can't see so much as paint stress.
    Help!  I Think I Bent My Sturgis Bullet-20170812_121314.jpg
    Help!  I Think I Bent My Sturgis Bullet-20170812_123615.jpgHelp!  I Think I Bent My Sturgis Bullet-20170812_123553.jpgHelp!  I Think I Bent My Sturgis Bullet-20170812_123506.jpgHelp!  I Think I Bent My Sturgis Bullet-20170812_123454.jpgHelp!  I Think I Bent My Sturgis Bullet-20170812_121356.jpg

    I should just shut up and ride it, huh?

    -F
    It's never easier - you just go faster.

  7. #7
    because GIANT
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    hang it from the ceiling, verify
    BB is dead level, adjust it so BB is dead level

    then hang some plumb-bobs around it
    "Eating Spam, and Oreos, and drinking Thunderbird, baby" -Baby Huey/James Ramey

  8. #8
    Not really fixed.
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    You'd see it if you bent any of the tubes on that bike, hydroformed aluminum doesn't deform silently. I'm going to hazard a guess that your headset could be too tight/loose, or your front hub needs some finagling in the dropouts, or your tire pressure is different, or your.....

  9. #9
    Professional Crastinator
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    Head Angle Correction

    Trying to get a replacement frame is turning out to be nearly impossible. BD offers them with a Bluto, but I already have a Bluto that I don't even use. Um, that is, until now.

    Just as an experiment, I took my newly-reconditioned 120mm Bluto back out of the box and jacked up the pressure making it virtually rigid. I also added 2 more tokens, bringing the total to 5. The steering manners were somewhat restored to normal! I've since fiddled with it and am running it at about 10-15% sag. The tokens keep it in "short-travel" mode, which maintains a tolerable steering geometry. The axle-to-crown is well over 500mm now and it steers pretty slow, comparatively, but at least I can ride no-handed. Now I can get ready for Winter.

    -F
    It's never easier - you just go faster.

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