Originally Posted by lawkd
Yep, that's where it happens a lot due to undertensioning. The left side rear is always prone to undertensioning, because of the dish. Even when the right side has good high tension, it can be difficult to get enough tension on the left side. The more extreme the dish, the more of a problem this is.
Yeah, Sheldon Brown actually suggests building new wheels half-radial due to this problem. Next time I build a non-fixie rear wheel I'll definitely be doing this. Unfortunately, my wheel has an 8/9 speed freehub designed for 130 mm spacing, so the dish is pretty huge.
Originally Posted by lawkd
You may need to replace all the spokes to keep this from happening, since they are probably all compromised now, at least on the left side. My personal rule is that three broken spokes = three strikes. Time to rebuild the wheel! And of course, get the tension as high as possible for your rim, and even tension from spoke to spoke. If you can respace your hub at all to decrease the dish, that helps too. It all depends how much room you have between your outboard cog and your dropout.
Makes sense to me. I only replaced the spokes that were visibly fatigued, and I concentrated more on even tension rather than perfect lateral trueness. No broken spokes for the past 2 months, but I'm aware that the problem may recur. I'll look into decreasing the dish, that sounds like a great idea.