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Old 07-14-2008, 10:41 AM
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cachehiker cachehiker is offline
Motorized Bicycle Member
Join Date: Jul 2008
Location: Hyde Park / Logan, UT
Posts: 35
Default Re: Ripped Out a Spoke ?

Originally Posted by misteright1_99 View Post
Bicycles were not meant to have motors, or ride 20 miles at 25 mph.......
This may be true for the typical Walmart bike but I recently rode my bike for 150 miles at 23 mph without benefit of a motor. I don't see how a motor is going to put much more stress on a wheel than my own pedaling. If that's not enough I've now put a total of 8000 miles on that bike and the rear wheel only has 20 spokes!

I build most of my own wheels from the ground up. I've done about 20 of them now. Having ideal spoke tension means bombproof wheels that don't look like they should be.

The problem is the nature of the product. Cheap rim, cheap spokes, cheap hub, machine laced and machine tensioned at whatever setting gets them built and out the door fastest. What you very often get is a 36 spoke wheel with 12 spokes doing most of the work (high tension) and 12 spokes that are just along for the ride (low tension). As far as the bearings go, same deal. God only knows what the bearing preload was. Too tight or too loose? Not enough grease? Even good bearings won't last.

If the rim is puckered you should NOT reuse it. I'd hesitate to reuse the spokes too. Buying a similar Sun AT-18 rim and 36 generic straight gauge spokes is about $30. Paying the local bike shop to build the wheel back up will likely run you another $35. The best wheelbuilder here in the "Happy Valley" charges $50 and so would I. However, you can probably pick up a basic machine built wheel for $40 and they will probably verify the tensioning for free.

If it's way off the wheel will need to be retensioned and they may or may not want to charge you for that. Every nipple is backed off until the threads just barely show and tightened a turn at a time until the tension is correct. The wheel is then dished (centered) and trued (straightened). It takes me about a half an hour for a basic retensioning and an hour or more if it's MY wheel and it's built with an $80 hub, $70 rim, and $30 worth of spokes.
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