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  1. #1
    Texas Tornado copswithguns's Avatar
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    Bouncing wheel=needing to re-true wheels?

    This is probably very dumb (aka perfect for the 41). Last several times I've cleaned my Roubaix, I have bounced the detached wheels, with inflated tires of course, to sling the water off them before re-mounting on the bike. Just to help speed the drying process. This got me to thinking, could that cause the wheel to go out of true? I'm paranoid now and quit doing after thinking about it.
    Last edited by copswithguns; 03-20-14 at 02:45 PM.
    "Speed never killed anyone. Suddenly becoming stationary...Now that's what gets you." -Jeremy Clarkson

  2. #2
    blah blah blah milkbaby's Avatar
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    I doubt you're putting much side force on the wheel to untrue them, at least considerably less than when you ride your bike and make a turn. Think of the side forces on the wheels as you lean the bike to turn.

  3. #3
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    I bounce the whole bike all the time after a wash or rainy ride. you'll be fine

  4. #4
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    Not trying to be snide or anything, but if you don't notice or see any wobble, you've got no worries. As others pointed out, everytime you hit a bump, you created forces caused by your weight and speed that transfer onto your wheel. And most any well-built wheel can take that kind of stuff without any issues whatsoever.

  5. #5
    Texas Tornado copswithguns's Avatar
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    Oh I notice and see a wobble, I have improperly tensioned spokes that don't let the wheel stay true and currently have a spoke tension meter, truing stand, etc. in the mail right now so I can true them myself. Just didn't know if I was contributing to the problem or not.
    "Speed never killed anyone. Suddenly becoming stationary...Now that's what gets you." -Jeremy Clarkson

  6. #6
    More Speed = More Work
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    Unless you're a) slamming them into the ground, or b) bouncing them sideways (i.e. not vertical), you're putting way less force on the rims than when you're riding. If your wheels aren't true, that isn't the cause.

    Cheers

  7. #7
    pan y agua merlinextraligh's Avatar
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    Quote Originally Posted by Zero7 View Post
    Unless you're a) slamming them into the ground, or b) bouncing them sideways (i.e. not vertical), you're putting way less force on the rims than when you're riding. If your wheels aren't true, that isn't the cause.

    Cheers
    True.

    I'll take my wheels, throw them out 10-12 feet, with enough back spin they come back. Stupid, purposeless, but fun and yet to cause damage.
    You could fall off a cliff and die.
    You could get lost and die.
    You could hit a tree and die.
    OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.

  8. #8
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    Not to belabor this, but think about it: Supposing the wheel weighs 2 lb, and OP, you plus the bike weigh 200 lb. The issue is the energy absorbed by the wheel. So energy is 1/2 mV^2. The energy dissipated in the wheel when it is dropped a given distance is about 1/50 as much as if the same drop would occur with you and the wheel on the bike (1/100 X 2 assuming you land on both wheels and front-back weight distribution is nearly the same). Anyone who hops several inches over road obstructions and potholes knows that a good set of wheels just shrugs that off. So you could drop your wheel that far and much more with no problems. The exact calculation specific heights for comparable energy for the wheel alone and you on the bike is a bit more involved. You would have to figure the exact heights that the wheel would have about 7 (square root of 50) times the impact velocity that the whole bike and rider would have, but you have absolutely no reason to attribute your wheel problems to the bouncing. Unless one of your kids is dropping the wheel off your roof of course.
    Robert

    My hero: "Tar-Baby ain't sayin' nuthin'..." (Joel Chandler Harris, Uncle Remus")

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