Yeah, destroyed half of my Surly fixed/fixed hub w/Surly cog/Dura Ace lockring tonight....

Assembled my bike after it took a ride in my buddy's car... (biked to his house, grabbed his car, tore bike down and threw in trunk, drove to the airport, picked him up, got a ride home and re-assembled bike)

Didn't double-check my chain tension upon re-assembly.

Took off to go meet some friends at the local brewpub... noticed some slack in the chain... thought "damn, this isn't good".... couple seconds later, threw the chain off my ring, unscrewed my cog, stripping the lockring threading right off, wrapped the chain around the axle, locking the wheel at 25mph, about 2" away from a passing car.

Total damage: I side of fixed/fixed hub gone for good, 9 spokes need replacing.

Looks like you got a chunk 'o chipmunk caught in there too (left side). The carnage!

next time, when you conscious says something to you, act on it! Glad you're ok!

I'm inclined to believe in a different story: You lockring/cog assembly wasn't tight enough or the threads on 1 or more of 3 parts was crap/buggered by subpar user => cog came off => chain came off => carnage.

A simple dropped chain causes a minor scare and zero damage to lockring threads and such.

i would've assumed the same (cog/lockring too loose) but for the fact that the hub looks like it'd been ridden as assembled for some miles...
still, i don't see how the chain hopping off would cause such a disaster..

something must've failed before the chain came off...

(also i wonder if lacing the wheel in the other direction would've kept the chain from jamming so badly)

did you like rotafix your cog off while riding?

Agreed. Simply put, dropping your chain is not going to rip the cog off of the hub.

Especially if ripping the cog off requires it to tear through the lockring.

if the dropped chain gets caught on something and locks up the rear wheel it seems pretty possible to me. Think of it as violent rotafixing.

Entirely possible.

That doesn't make any sense.

The most force you'll be able to apply is determined by the friction of the tire, it'll be the same as a hard skid. It doesn't matter if the chain stops moving because it's caught on something, or if it stops moving because the cranks aren't moving (skidding).

I run a 38c tire, going 25mph, am 190lbs. Chain fell off the chainring and wrapped under itself at the cog, heard it tear apart after the chain fell. Trust me, the cog and lockring were on there nice and tight.

I was going at a speed where I would have had to lean way forward to even think about skidding, but had all my weight on the saddle.

skids are limited by rider strength not friction.

I should have taken a picture of the chain wrapped under itself, then perhaps you guys would believe me.

i'd like to see this one on mythbusters.

Regardless of how it happened. that sucks dude. Best of luck rebuilding wheel, and listen to your instincts in the future!

As long as Kari gets to wear the spandex.

totally.

Finally something that we can agree on!

my cog got reversed rota-fixed off once.
stripped the hub pretty bad, but... j/b weld fixed that in a hot minute.

+a billion...i can't tell you how many times something bad has happened, and i knew it was going to, but i just kept going.

and now you're a father?

Word, last night on the ride home i noticed man chain seemed slack. I was close to home and ignored it, then forgot to deal with it before bed.

I remembered on my way out the door at 6:40am today, and dealt with it, making me late for work, but I'm glad I did it. Also glad nothing bad happened.

Yeah, it sucks when the man chain is slack.

OH NO, I MEANT MY.

My linguistics are regularly exquisite, piss off.