[QUOTE=JohnnyGalaga;14078863]It's getting frustrating how expensive bicycle maintenance is. I'm starting to wonder if pedaling isn't cheaper than driving to work if you already own a car.
Is it normal to get 1-2 broken spokes in your rear wheel almost every month? It costs like $15-$25 to get get 'em fixed at the bike shop and I don't think it's worth it anymore. Or if you need a wheel trued, that's another charge.
You bought cheap machine built wheels, neglected to stress relieve the spokes or bring them up to high uniform tension, and the ones in the failing group(s) (ex - rear drive side) have reached the end of their fatigue life.
You're probably a heavy guy which increases the magnitude of stress variation as tension drops 750 times a mile with each revolution which in turn decreases the number of cycles they survive.
They'll continue to break like popcorn kernels popping until you've replaced all of the spokes in the failing group, and if your bike mechanics aren't marginally competent wheel builders the new ones will break too.
Assuming you've had a few spoke failures and talked to your bike mechanics about the repeated failures they're not competent. Learning maintenance and wheel building would be the right thing to do, but if you lack the patience (it's easy enough school children can do it - that's how Jobst Brandt tested the instructions in _The Bicycle Wheel_) to do it yourself you need to find a reputable one-man operation (Peter White, Psimet, etc. Just getting a reputable shop isn't enough because you can get whatever bozo currently works there ruining your new wheels instead of the guys that earned the reputation).
I don't think anyone knows how long high-quality stainless steel spokes last when correctly built into a wheel. Jobst has 300,000 miles on a set of 15/16 gauge spokes without breakage and some of the bikeforums.net regulars have over 100,000 miles on theirs.
I never broke a spoke in a wheel I built (1500 - 4500 miles a year since building my favorite wheel set 14-15 years ago at weights up to 215 pounds + 15 pounds of luggage).