former weightlifter turned triathlete repeatedly breaking hanger Every year, it seems I am on a training ride 5-10 miles from home and while torquing up, I snap the hanger throwing the rear derailleur into my spokes and locking up my rear wheel. I am 205lbs and 5'10" and still squat pretty heavy so I am wondering if the combination of my weight and my force is wearing out the hangers quickly causing this and if there is a known way to check this for fatigue before I get on the road. I use a 2012 GTR Series 5 aluminum bike. If I ask at a bike shop, they will just try and sell me a tri bike. I want a tri bike but I don't want one if it wont change anything in my sprint and olympic tri experience.
The way you asked the question, it sounds like you think the following is happening: first, the derailleur hanger wears out/weakens, then it snaps, and this causes the derailleur to go into the spokes.

It is much more likely that the chain of events is the following: the derailleur is mis-adjusted, when you shift to the largest cog on the rear, the derailleur goes into the spokes, and this causes the derailleur hanger to break off.

Possible causes:


the inner limit screw on the rear derailleur is too far out, needs to be tightened a bit, until it reliably keeps the derailleur from moving too close to the spokes
the chain is too short, and when you shift onto the largest rear cog and the largest front chainring (not recommended in general), the chain gets too tight and this rips off the derailleur.