Old 04-24-14 | 07:14 PM
  #21  
kevbo
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Joined: Oct 2007
Posts: 330
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I used to break lots of spokes before I learned to build my own wheels. No broken spokes on the 8 wheels I have built.




First off, know that spokes rarely break due to overload, they break due to fatigue, and this due to the spoke tension being too low for the weight the bike is carrying. When the tension is low, then the spokes go slack as they go past the bottom, or from pedaling or disk brake torque. It is this alternating slack-tension cycling that fatigues the spokes. The spokes must be brought to
high tension when the wheel is built. Once it has been ridden a ways with too low tension, the fatigue cracking has begun, and tensioning the wheel will not help unless all the spokes are replaced.


One thing I did not see yet in this thread is stress relieving. Sheldon's site explains how to do it. It seems like voodoo if you are not a metallurgist, but the science is sound. This also needs to be done prior to riding the wheel.

If you are on a budget, it is less labor to get a cheap machine-built wheel (low tension) and increase the tension and stress relieve it.

On a derailleur (highly dished) rear wheel, consider half radial lacing. Lacing the left side radially, heads-out will help keep those spokes from going slack. You can also use the next size smaller spoke on the left. Which will also help. Normally radial lacing a hub that has previously been conventionally laced is a no-no, but the left side of a dished rear wheel has such low spoke tension that the risk of hub failure is minimal. Locking compound may be needed on the left side nipples.


finally, consider a suspension seat post. Not only does this reduce the shock on your butt, but also reduces the jolts that all bike components including spokes. The telescopic type are not expensive, and you can crank the preload up so that you do not bounce at all when pedaling on smooth pavement.
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