Sunday, January 13, 2013

Truing A Bicycle Wheel: Schwinn New World

This weekend I got a chance to finish cleaning up the front wheel. I used the Dremel brush, bronze wool, and WD 40 method that I employed for the rear wheel back in December. That method can be seen in an earlier post.

After the cleaning, I  cleaned and lubricated the front hub. The hub is a Schwinn script type hub with basic ball bearing cages inside. I flushed it with WD40, then added some medium weight oil, then sealed up the bearings with lithium grease, again similar to the rear wheel back in December.

After the hub was cleaned and the rim de-rusted, I set about truing the wheel. There are several ways to true a bicycle wheel, but they're all similar. First, you can put the wheel in the bike frame or the fork, then watch for wobbles and correct them as needed. Second, you can put the wheel in a dedicated truing stand and, again watch for wobbles and hop. Third, you can use a spare bicycle fork as a makeshift truing stand.

Regardless of what you are using, the basics are the same: you tighten spokes where you want to move the rim in towards the hub or towards the side you're tightening. You loosen a spoke to allow the rim away from the hub or to "push" the rim toward the other side.

If you look at the bicycle wheel, you have basically 2 types of spokes for truing purposes, left spokes and right. Some spokes connect the rim to one side of the hub and some to the other. When you tighten a spoke, you pull the rim to that particular side.

1. Put the wheel into the fork or frame or stand, and make sure it is centered. Tighten it into the stand, fork or frame as needed.

2. Spin the wheel slowly and watch the rim between the blades of the fork or frame. If you see the wheel jump to one side or the other, the rim is out of true. Also, look from the side and see if the rim spins "roundly" or if it "hops up and down". This means the rim is out of round vertically. You need to correct both.

3. IMPORTANT: use a PROPERLY SIZED spoke wrench to turn the nipples connecting to the spokes to the rim. There are 2 little flats on the nipples so the wrench will fit tightly. DO NOT attempt to use pliers. If the rim wobbles to one side, find the spot where the movement in the rim is. Then LOOSEN the spoke connecting the rim to that side of the hub by 1/4 turn. Next, TIGHTEN the opposite spoke (connecting the rim to the opposite side of the hub) 1/4 turn. Test again, and repeat until the rim is centered.



4. If the rim is out of round, check to see if the rim hops up or down. If the rim hops AWAY from the hub, find the spot of the hop and tighten ALL spokes in the area of the hop 1/4 turn. This will pull the rim back towards the hub. If the rim hops TOWARD the hub too much, then LOOSEN the spokes in that area.

5. Keep checking both the round of the rim and the left and right wobble.



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