Wheels - Truing
Truing the wheel on a dirt bike sounds tough, but you CAN true your own wheel. The biggest trick is to be patient, and work in small steps.
If you have a wheel stand, mount the wheel in it. If, like most of us, you don’t have a stand, mount it back on the dirt bike. If it’s a rear tire, leave the chain off so the wheel can spin freely.
If you have a dial micrometer, you can use it to measure roundness and side play (i.e., is the wheel warped?). If you don’t have a micrometer, join the other 99% of us. You can easily use a piece of wire as a pointer. You’re best bet is to drill a small hole in a chunk of wood, stick in one end of the wire, then bend the wire until it almost touches the rim.
Now slowly spin the wheel. If you’re lucky, the rim won’t move up or down. If it does, locate the spoke at the highest point of the wheel. Tighten it slightly. Then tighten four or five spokes on each side of that first spoke. Tighten each one a little less as you move away from the highest spoke. If you tighten the highest spoke half a turn, then tighten the next spoke three eighths of a turn, the next a quarter turn, the next one eighth of a turn. Remember, do this on BOTH sides of the highest spoke. Spin the wheel again, find the highest spoke, and repeat. Once you’re close to “up and down true” and before the spokes are too tight, check the side play.
To check the side play of the wheel, set your pointer close to the side of the rim. Spin the wheel slowly and locate the point that moves closest to the pointer. Find the closest spoke that goes to the opposite side of the hub and tighten it slightly. Now tighten every OTHER spoke on either side of that spoke, decreasing the amount you tighten as you move away from the first spoke. Double and triple check that the spokes you are tightening are going to the opposite side of the hub. This will pull the rim, at that point, in the direction of the hub. Keep repeating the spin, locate, and tighten cycle until the wheel no longer moves to the side. And, just to complicate it a little, make sure the wheel is centered in relation to the forks or swing arm.
Keep alternating between checking for side to side, and up and down, until the wheel runs true.
If you feel the spokes are getting too tight and the wheel isn’t true, you can also make adjustments by loosening some spokes while tightening others. Loosening a spoke will move that part of the rim further from the hub. Remember to loosen the 4 or 5 spokes to either side as well – same as when you’re tightening.
If everything seems to be going wrong and the wheel is getting more out of true, stop right away. Review what you’re doing. Are you doing it right? If necessary, loosen all the spokes back up and start over.
Make lots of little adjustments over and over, rather than trying to do it all at once.
Once the rim is running true and centered, you can start tightening up all the spokes about one-quarter to one-half turn at a time. After each batch of tightening, check the wheel again to make sure it’s still true. When the spokes are tight enough, you’re done!