i know that factually, they are much stronger than aluminum. but it sure looks nasty when broken. my mate had his snap at the brake lever clamp. he had already completed his run and it was after a drop, not during. i'd post the pictures if i could figure out how to do so.
i put them at the link below if it works…
http://imgur.com/a/cXTht
That's caused by one of two things:
- An overtightened bar clamp
Or
- an impact to the brake lever
You can tell because the break is right at the clamp and the bar hinges away from the clamp screw.
Most likely overtightening though.