Broken Crankarm
 

Look at what I did. I was accelerating out of a track stand in the middle of a busy intersection, I ate total $#@t. The crank is stock on a 2003 specialized langster. Do you think this result of a crappy part or my superhuman strength? (any suggestions for a new crank would be much appriciated)

http://photos21.flickr.com/33683074_38f188634a_m.jpg http://photos23.flickr.com/33683234_df99ec9c5a_m.jpg

Nothing lasts forever.

Here is my limited knowledge classical explanation of what probably happened to your crank:

A crack started somewhere in the upper left hand corner of the broken cross-section in the 2nd picture. This crack was present for a long time. It grew and grew over a period of weeks. You can tell because that area is discolored from oxidation and microscopic crud as the crack moved slightly and admitted the outside atmosphere.

One day, at the worst possible time, the crack reached some critical length and broke apart entirely in one instant.

What can you do to avoid this?

Nothing. It is the failure mode of aluminum. The only thing you can do is to inspect your cranks regularly (once a month or so). These cracks grow slowly at first, so you have a chance to catch them if you keep everything clean and look closely. Also, be sure to track down the cause of any squeaks and creaks on your bike-- it could be a crack!

Thats funny, last week I was hunting for the source of a squeak, I thought I had solved it by changing pedals, next time I'll definately pay more attention to the cranks.

Didn't you crash recently? That could have started the crack or weakened the material. (Super)human strength is rarely enough to break a two-year-old crank (I hope)

holey moley

one time a broke a crank on my schwinn road bike 2 years ago... was in an intersection and stood up to accelerate and bam i ate total ****, my balls met the top tube and everyone driving their cars could give a **** about my body sprawled on the ground lol.

i say it's superhuman strength, we are genetic freaks of the bicycle

I have crashed recently, but I laid it down on the left side. Aside from that, the bike goes through hell on a weekly basis. I'm kind of glad it happened though, nothing like an excuse to upgrade.
(anybody have any recomendations for a new crank set, I was looking at the miches but I heard that they have a proprietary bcd, and you can only use miche chainrings.)

yeah, miche is 135mm BCD, which is the Campy road standard. So they're not really "proprietary" per se.
If you want 1/8" rings for your miche cranks, you're limited to Miche and TA, I believe. But if you're happy with 3/32" then you have more choices.

FReakiN Chri@3

that crank muxt be cheap, super cheap

it happens to cheap parts all the time,u get what u pay for!

*******You can use a Campy BB w a Miche Crank...its a good combo for the dough

That's a Specialized crank, isn't it? It really shouldn't break unless it is crashed, IMHO. Even if you rode it aggressively, skidding and all that, and you weigh 200 pounds, a crank mustn't crack like that.
Whatever... Maybe drop a line to Specialized... Not really a warranty issue as it's 2 years old, but at least they'll know they're makin crap.

Everyone here seems to think there was a manufactuing flaw or a hairline fracture, but I think, after getting in this miserable and silly accident, you deserve to be told something nicer: It obviously happened because you are super duper strong. Have your next crank made from cast iron.

Looks like a cheesy cast crank to me. See if you can replace it with a forged crank.