I keep breaking pedals, as in putting power into them end they stop working and parts fall off breaking. I'm trying to rind at higher cadences in the 80-100 range and my average speeds have been in the 11 MPH range riding in mostly a 51" gear on flat or false flat roads but with lots of stop signs and traffic lights. so far I have crushed one bearing, which might have been a manufacturing defect, and broken the cages off twice now. I re-threaded the pedal body and put the cages back on again.
 
Am I dealing with bad pedals? I don't think my power output is the cause for this, or I would be doing a much higher average, because my cruise speed has been in the 15 MPH range. Yes, I'm slow but I get there eventually. If I am breaking pedals because of the power I am generating I can't wait to see the times I run on the drag race trike I'm building

I've been on two bike tours with a combo of 420 lbs and climbing hills and haven't broke a pedal. I might say that it could have been faulty pedal. What kind are you using??
  P.S. i have the pedal extender on the last run.
 Later Thomas J  

Paul even with twice that load I've never broken a pedal. I snapped a crank arm once but that was unloaded.
Opus,
If you think it could be from putting your feet so far out  power_bent mentioned pedal extenders which would push the pedal more to the outside so you could be centered. I have a set which I tried which didn't work for me but I'd be glad to send em on over to yah. They'd push the pedal out a little potentially evening the force between the sides. Or perhaps a pair of power grips?

Quote from Opus the Poet on Jun 20^th, 2009, 11:24pm:

I'd suspect bad/cheap pedals. I've blown up two SRAM Dual Drive hubs and one Ultegra hub on my trike using inexpensive pedals with Power Grips and I only wore out the bearings on one pedal (wore out two sets of Power Grips though). I use Shimano A530 pedals on the trike and the LWB bikes now and Shimano A520s on the Corsa. I even burned up the bearings in the stock FSA BB on the Corsa a couple of months ago and the A520s are still in great shape, though I've worn out two pairs of bike shoes in the past year. Hoping my new Sidis do better.

Cages back on, but I noticed something on the ride. I was trying to get across an intersection near sunset so that I could see the shadow cast by the bike on the pavement, and I was pulling the front wheel off the ground under power. Granted this was on Gigi rather than on my Stratus, but still, that's a lot of short term power. So we have the foot way out over the end of the pedals, we have a huge amount of power going into the pedals, and we have cheap pedals. We have the perfect storm for destroying pedals.