recursive

I've seen a lot of approaches to crashing. I thought maybe even most of them. I innovated a new one today.

Here it is, as near as I can tell.

As I was giving a hard kick over the top of a hill to try to catch a rider ahead of me, somehow, the torque on the cassette pulled the wheel out of the dropout. It jammed itself into the stays on the left. Being out of the saddle at the time, I was not expecting for the rear wheel to lock up. For a brief moment, I thought I could save it. But I went down hard. I cracked my helmet and got a curious assortment of road rash, featuring at least four distinct patches on my left knee. On the bike, I'm out a wheel, a saddle, and bar tape, and maybe some cables.

Does anyone know how something like this could happen? I'm not a mechanical expert, but I've never heard of a rear wheel coming out of position before.

Yes, the QR was closed tight.

MrCrassic 

Maybe the dropout was loose...did you see any damage happen to it?

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TONYKART125

you got too much power

Bob Dopolina 

I had this happen on a bike where I'd removed/installed the wheels so many times that the inside of the drop out was worn smooth. I roughed it up with a dremmel (GOD I love that tool!) and it was ok after that.

Check your QR. Is it the same one you've been using? I have also had some QRs (from one particular manufacturer...cough, cough, ALEX, cough...) that felt tight to close but slipped during hard efforts.

Heal up quick.

recursive

Nothing visible

I don't know what kind of QR I had on it, and it's in the shop now. It sounds like this could be similar to what happened to me. LBS guy said that with a normal properly functioning road bike, it should be impossible to pull the wheel out of the dropout because of the design. He suspected an axle problem.

Thanks for the kind thoughts.

ok_commuter

Right after I got my Waterford, I had that same thing happen when I stood up to make a move... in traffic.

Make sure your wheel is straight, perfectly seated. Make sure your skewer is really tight and closed all the way.

That's all I got.

EDIT: I've got chromed horizontal dropouts, which makes an event like this more likely.

scotch

are your dropouts slightly more horizontal than vertical? they are on my bike, and when i got it it had Campy skewers that had a small acorn with small grooves in it. if the cam wasn't cranked down super hard, the wheel would come out under torque with the same results...wheel slammed into stays, me over the bars.

i solved this issue simply by getting a Shimano skewer for about 10 bucks...bigger acorn, deeper grooves, no more slippage.

andr0id

It happens on occasion because....

... it wasn't closed tight enough.

Don't know what kind of skewers you got, but the boutique, super lightweight, external cam skewers tend to not clamp hard enough for some horizontal dropouts. Especially if they are chromed or stainless.

Basic Shimano or Campy skewers are far more reliable when they are closed correctly. The lever should get tight 90 degrees from the bike.

markieta

Chain/seat-stay flex leading to ineffective clamping force?

^Is this even possible? (im curious..)

roy5000x2

A few things I can think of...

QR wasn't tight enough
QR was tight, but didn't have enough grip on the dropouts
Bent axle on the rear wheel
Problem with the dropout positioning on the frame

Since you were out of the saddle at the time, there would be less weight on the rear wheel. By a sharp increase of power being put out by you getting out of the saddle to attack the hill, this could also cause even less weight on the rear of the bike (it's possible to spin the wheel by doing this). The combined force of the power through the chain pulling down on the cassette, along with some sort of failure in the QR, and finally the reduced weight on the rear of the bike could be enough for what you described to have happened.

anticlimbactic

did it once in traffic, taking off from a red light. locked up, skidded, popped up, all kinds of haywire but I managed to stay upright. Basically huge torque + ever so slightly loose skewer (and from a trainer I would later find out - the shop never put my shimano back in). Ended up jammed against the stays like you said.

Heal up and make sure that stuff is straight and tight!

DannoXYZ 

What kind of skewer did you have on that wheel? Internal-cam ones with steel inserts on the gripping surfaces are the ones I'd go with. Yeah, they leave little teeth marks on your dropouts, but they never let go either.

recursive

I will find out what kind of skewers they were. I don't know what's on it, and it's currently in the shop getting restored to life. I wish I could heal my own injuries with money.

Psimet2001 

Damnit man! when are you going to stop crashing! You have taken it to a new level for sure.

Still my favorite of yours...i loop it for hours when I am bored....:
https://www.youtube.com/watch?v=jfs55TB9srg - 0:12 in - white helmet.



BTW - I have to agree with the loose skewer. I have had it happen to me before and it was always either that the skewer really wasn't clamped down as tight as I thought it was or that the skewer broke.

EDIT - second favorite part is the guy saying "that's why you gotta be careful" at 0:31-ish

darkmagus

Also, if there's too much axle protrusion then the skewer can be 'tight' but not actually be gripping the dropout. May not be the case but definitely something to check.

botto 

what place was he sprinting for? 10th?

Metzinger

+1 Also check skewers for evidence of titanium.
Steel shafts are a must for solid clamping power.

Wheels used to pull out more when we raced steel frames with chromed horizontal dropouts.
And we weren't all on the juice, like you kids today.

recursive

Probably like 18th, but money was 20 deep.

botto 

was it worth it?

recursive

With the benefit of hindsight, I'd have to say no. Good question.

botto 

that wasn't one of your broken bones crashes, was it?

recursive

No, just some bruises and road rash. I've actually only broken two bones in my life, and neither of them were in races.

ColorChange

I've ridden with you Recursive... I'd go with too much power.

arshak

Happened to me when i had a Ti skewer in the rear. The torque flexes the Ti and causes the rear wheel to be pulled out to one side (in my case the left chain stay). Happened during a race and while I was diving into a corner. Was able to stop from crashing but I replaced my skewers with Shimano stuff and no problems after that.

bcart1991

I crashed exactly like this a few weeks ago. Your QR wasn't tight enough.