Join Date: Jul 2006
Location: Toronto (again) Ontario, Canada
Bikes: Norco Bushpilot (out of commission), Raleigh Delta
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Originally Posted by audiofx
I bought my Trek 7100 hybrid back in May and so far I have done around 850 miles this season. Unfortunately, 2 out of my last 3 rides have resulted in broken spokes on my rear rim.
My weight has stayed the same at 245 (need to work on that diet!). Am I just running into bad luck or is there a reason these spokes are breaking now?
I usually drive to the trails in my car but the last few trips I have taken the road to the trail with my bike. Our roads aren't the best here and I'm avoiding potholes and re-paved sections like crazy. The bike paths are pretty smooth. Could the bumpy road trip be the reason my spokes are breaking?
Today, the spoke broke on the bike path up one of the larger grades. I was not on the road when it happened.
Broken spokes are usually caused by one of three situations .
1) The wheel does not have adequate tension, this causes spokes to flex and when wire is flexed rapidly it breaks. As spoke count is reduced (from 36), or rider weight increases (above 150lbs or so), spoke tension becomes more critical.
2) The spokes have been damaged, for example by a kamikaze rear dérailleur. A kamikaze rear dérailleur is one that shifts into the spokes, committing a rather spectacular and sometimes very expensive suicide.
3) The rim is not designed for the rider weight -- or has been damaged, sometimes the rim will crack around spoke holes, weakening the rim.
Have a good look at the rim, around the spoke holes, if you don't see cracks, then given your distance it probably isn't the rim. If you have not had a kamikaze rear dérailleur, or a spoke killing crash. Then that leaves spoke tension, which is usually the problem. A wheel can over time lose some tension, if this loss of tension passes below the threshold you can start breaking spokes. When you start breaking more then 2 spokes, the wheel needs to be re-built with all new spokes and properly tensioned and trued.