I was attempting to cross this highway east to west. I was first in line at the light (on this bike).




The light turns green and I stand on the pedals to start across and the BB axle snaps. I go over the bars and somehow end up landing on the front wheel.






What was left of the axle punctured my knee.



I sustained a few other abrasions, cuts and bruises and the bike is ok with exception of the BB. I had a huge audience of lots of rush hour traffic sitting at the lights waiting for their turn. Good times had by all.

heal fast! Bike and you.

I dunno, bike looks like a candidate for euthanasia.

You amputated the bike's crank.... looks like it tried to amputate your leg.

Whoa! That's one nasty surprise. Never seen that happen before. It's a good thing that it didn't happen at a worse time, like riding w/traffic at cruising speed.

It's tough for me to tell by the pics.....is that BB spindle secured w/a bolt, or a nut? If it's a nut, then the square taper portion is solid. If it's a bolt-on, then the spindle is hollow for at least the length of the taper, and weakened to the extent of the major thread diameter. OTOH, there are plenty of bolt-on spindles out there. I'm just wondering if this was a factor, or maybe just a defect in material. Does anyone know how common this failure is?

I hope the bruises don't last long................

It's secured by a nut and as far as I can tell is the original. The bike is a '74 so it's probably due for a new BB anyway.

A bike that old perhaps had some metal fatigue in the BB. I had my '82 re done because I was scared it would let go. Time for some maintenance Reich...you heal up there buddy.

The spindle was cracked. Look at the concentric marks on the fractured face. We call them "Beach Marks" in the fatigue analysis biz...

The crack gets gradually larger and larger as you subject it to an alternating load, until it fails catistrophically.

Just replace the spindle and crank and you will be good for many more miles.

Glad you are OK.

Glad you're OK. Every cloud has a silver lining - when you replace the spindle and crank you'll have a good opportunity to clean that drive train!

You are bleeding because, it hit your socks! Badge of Honor!

Ouch! That BB really did you in

I've always feared standing to hammer up hills on my bike because it is a fairly cheap bike (Trek, though, not some X-Mart bike). I just have this feeling that the axles on either the BB or the ones that connect the pedals to the crankarms will have some unseen defect and snap...

Yikes...

Yoikes! Glad nothing more serious happened in such a high-traffic location!

I too have broken a BB axle. That one was only 4 years old, on my Raleigh M30 MTB the day after moving to Maryland for grad school. It sucked! I landed my crotch smack on the top tube, which didn't feel so good. And it cost about $80 because they apparently had to drill the BB cups out, since they were totally rusted in place. And the bike got stolen about 2 months later

So, yeah, broken BB axle = bad!

Ouch. That's a fine bit of destruction. I'm glad you didn't face-plant in front of a speeding HVAC repair van or something. Definite opportunity to upgrade the components, though!

I replaced the BB on my ancient (30+ years) Raleigh just a couple of weeks ago. I gotta tell you, the new-design sealed bearing BBs are light-years ahead of the old style, ball-bearing, lockring/fixed cup/adjustable cup things of the past.

Just pop in a Shimano sealed-bearing unit (they come with solid or hollow spindles, whichever you want). It's a breeze, and requires next to no adjustment compared to the old onese. And the sealed bearings mean no maintenance.

I sincerely appreciate the acknowledgement, thank you.

Does it really look that bad? I wipe it down before every lube job. I thought I was doing good

By the way, I just had a co-worker confirm that I dislocated my shoulder in the accident. That was a new experience for me so I wasn't sure what actually happened. Popped it out last night while stretching. Interesting for sure.

ouch !

sorry to see something like this... I had a big fear that my BB was going to let go in some unexpected way resulting in violent trauma to my grey matter...

Lucky for me, it blew up internally, but the cranks stayed on !

So I replaced it with a new shimano sealed bearing kit and it has worked flawlessly (and smooth) for more than 2k miles....

>> Link to dead bb thread with pictures<<

What's really sweet is that this means you're a straight out MONSTER in the torque stakes. I've snapped a pedal spindle before, but never a BB. You get to join the olympic track team, automatically!

After a long 70 mile fast ride 25+over 40 riders in the peloton just ready to turn home I lift my right hand to say bye, left hand on handle bar hit a road reflector and......... judge by yourself,,,, looking for a caad 8 frame (cannondale) and of course need some rest ..........................not!!!

Don't that POP! feel good?