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Off center front wheel

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Bluefang12, May 29, 2011.

  1. Hello, Not sure if this is really the right forum to post this but i have a high powered Electric bicycle, does 60km/h with a range of about 20-30km. Its a fairly basic hub motor with a highly moddified controller and some high powered batteries normaly used in LARGE RC model planes. Currently does about 2-3KW

    Because its high powered i ended up buying a set of dirt bike forks and a motorbike wheel for the front, much stronger and better brakes then bicycle stuff and ended up been cheaper too. Problem was that the rim and tire were way to heavy so i re-laced a normal 26" bicycle rim to the motorbike hub and that's where my problem became worse.

    When i turn a corner and if i apply the brakes the front end dives abit and handling gets very funky, this is kinda expected as the forks are fairly soft and i know about about how you should try to never brake hard and steer at the same time on a motorbike, but i noticed on my way home tonight that also under normal braking my wheel seems to pull to the side its offset too. Could the handling under braking be compounded but the wheel been offset, its pretty bad i laced it thinking i needed to go to that side but it needed to be laced to the other side ;(.


     

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  2. I'm not sure whether you're suggesting that one of those spokes are out, which means good luck in finding & tightening the correct spoke, or that you haven't actually checked where the wheel clips to the bike for being off centre (I'm sure you're done the second).
     
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  3. Yes, your handling is definitely being affected by the wheel being offset from center. If you can fix it by re-lacing it, then your problem should go away.
     
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  4. Just eyeballing it, your handling goes to shit under braking because, when the forks dive, your trail is going negative. Negative trail makes the bike directionally unstable.
     
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  5. Personally I'd set the replacement rim in the same line the original one was..
     
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  6. Oh well, i ll take it off and re-lace it, shouldnt take too long seeing as now i have laced a wheel its actually pretty easy to get it close to perfect, if it was going faster then 60k then i would be worried about it, the original was off center abit too, its a mix mash of parts, but due to the sheer size of that tire it had slow handling so it didnt effect cornering that much. With the bike rim and tire on the other hand i have almost highsided it afew times now, right infront of the boss at work too ](*,)=D>

    About the negative trail due to fork dive, is there a way to combat that, were talking shitty china Dirt-bike forks here, or am i just going to have to harden the suspension as much as i can and wait till if get a proper bike to play on.

    Thanks everyone for the responses, I didn't really want to have to re-lace the wheel unless i knew it would remedy the problem.

    fyi: Converting a 50CC scooter to ~7-10KW electric running thru the CVT drive, then i ll move onto whatever sports/off-road bike i can get my hands on, cheaply, with a semi separate gearbox :) :D:D
     
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  7. Try turning the fork legs round so the axle is behind them. That will increase your trail and give you more reserve before it goes negative under braking. If the handling problem goes away, that was your issue. You will have somewhat heavier steering though.
     
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