Horizontal (rear facing) drop-outs and braking

dermabrasion

Yesterday, I braked hard at speed coming into an intersection. My back wheel came out of the drop out and would have flown of if it wasn't stopped by the chain.
I have a Cervelo P2 with rear-facing drop outs, and had quick-release wheel. I could have had the skewer tighter, but I did not think it was loose. Has this happened anyone before or am I setting this up wrong?
Thanks

doozerie

I've never used a bike with rear facing dropouts but I always assumed that accidentally ejecting a wheel from them would be an extremely difficult thing to do. My simplistic brain struggles to come up with a scenario where it could happen, the only thing that I can think of is that your skewer was looser than you thought and/or the wheel was not slid far enough into the dropout so the skewer didn't have enough dropout material to grip reliably.

I guess another possibility is that some lube, or more likely grit, got between the skewer/axle and dropout faces when you fitted the wheel, again compromising the grip. A tight skewer should overcome contamination by lube though, I'd expect. (I can think of no way to word that last sentence without it sounding stupidly smutty, so I'll just leave it there as it is!).

superlav

This has happened me on a P3 and I've heard of many cases of it happening other riders on bikes with similar rear drop outs. It's always under extreme braking, for me it happened at the turnaround point on an out and back TT.

It is generally something that only happens you once, after which you learn to increase the tightness of your rear skewer. If you are using lightweight skewers, it might be worth going back to standard as they do tend to have better clamping force.