QR Rear wheel shift in frame?
 

My son has an older carbon Scott CR1, he's pretty strong, recently he has complained his rear rear wheel shifts in the frame under load.

Not always, but sometimes enough to cause the tire to rub on the non drive side chain stay. He has a new QR coming.
Is this a problem with his tightening of the QR's? Worn dropouts?

What is your method for tensioning QRs?
Would a better quality bike's dropouts be precise enough to prevent this?

1. Tell your son to get a genuine Shimano or Campy quick release. The aftermarket quick releases that have the mechanism obviously exposed don't grab nearly as tightly.
2. To tighten a QR hold the lever out parallel to the axel and tighten the nut on the opposite side until it is finger tight. Then push the QR lever so it is perpendicular to the axel. Make sure you position the QR lever so that you can get a finger behind it when you need to release it.

I had that problem on my old 12-speed and it turned out to be a broken axel. It performed fine, but deflected a lot under heavy load. I'd check for that.

Agreed. The Scott CR1 is a relatively new carbon frame, and not an old steel frame with adjustable sliding dropouts. The axle should not move at all.

As Retro Grouch stated, get internal cam skewers and clamp them down tightly. That’ll likely be the end of it.

Thanks, I've just repacked the bearings for him, axle is good.
Internal campagnolo QR's ordered.

I agree with bikes with horizontal drop outs, an internal cam QR, clamped very tight is essential. An external cam QR just won't cut it (in my experience).

But a modern bike with vertical drop outs? i've never had any shifting, ever with external cam QRs. Is it possible?

hevysrf can you tell us if it's a horizontal drop out or vertical? The Campy QRs aren't a waste, but I dunno, I wouldn't think they'd be needed with vertical drop outs. I could be wrong and will welcome corrections.

Rear wheels shift all the time regardless if the wheel is quick release or nut. After you centre the wheel between the frame (and rim brakes if you habe them), keep an eye that it's not shifting as you tighten the nut each turn or half turn. Sometimes it may be handy to jam a spacer each side of the wheel to keep it in place as you tighten. The problem you have is that the qr wasn't tight enough before you closed the lever.

Don't tighten it too much that you can close the lever. The lever should go all the way parallel to the frame and not sticking out. If it's sticking out, it's too tight.

No, no no...and no. The frame has vertical dropouts. No shifting at all should be happening. You should definitely not have 'jam a spacer' on each side of the wheel. To set the tension on the q/r skewers tighten the nut end enough that you start feeling the lever tighten up when it's halfway through it's travel. Do NOT close the lever against the frame or fork.
ETA: To complete the proper information a nutted axle wheel should NEVER shift in the dropouts. If it does you're doing it wrong.

Thanks. I was about to post the same thing. If you’re doing it right, the wheel never shifts. Period.

https://cimg6.ibsrv.net/gimg/bikefor...d48ff9ea27.png


I'm an axle nut , 36 spoke, 50mm rim guy. didn't realize just how little clearance there is between tire and chain stay on these carbon diamond frames.





https://cimg8.ibsrv.net/gimg/bikefor...f00afba3b5.png
.

What are those pictures trying to show re: your problem?

I use external cam QRs with vertical dropouts, and I agree with this - my rear wheel doesn't shift at all, and never has.

Those drop-out slots, although vertical, seem oversized, and rounded off on the bottom ends, not really vertical all the way down. Or is the second one the derailleur hanger? I can imagine the wheel moving some - there is slop enough. Having enough clamping force should still work, IF the dropouts themselves can take it.

That pic of the NDS dropout seems totally wrong to me. My CF bikes all have a metal 'faceing' (prolly an insert glued to the carbon). Clamping directly to the carbon would be a total no/no for me...
A little more 'crunching and that axle end will be flush with the dropout side...
My guess is there 'was' an 'Insert' to face the dropout properly and take the skewer abuse (which fell off?) , which would account for the excess space in the dropout.
I wouldn't be using a QR with a serrated cap until some metal facing has been put back in place. That QR will eat the remainder of that dropout quickly...
Ride On
Yuri
EDIT: And the insert might also sleeve the inside of the Dropout, reducing the excess space and also taking the direct load off the dropout carbon. A good hard thump I can could see that dropout end cracking enough to loose a wheel.

can the mods combine this thread with the cracked head tube thread ?

appears to be issues one or both dropouts

might be more than Tulio Campagnolo himself can overcome

There are tons of bikes and forks w/ 100% carbon dropouts...zero metal. Been like that for years, over 10 at least.

maybe so, I don't go around checking dropouts... LOL, but my tarmac definitely has metal face on the NDS dropout...
Doesn't hurt to contact Scott, send them the pics and issue, and see what they come back with... especially the large extra space within the dropout. Are they that forward thinking to allow for a crappy wheel build?
TA droputs are one thing, but where there's a hard clamping effort on the resin face, I wouldn't be so happy. Myself, I will check future QR bikes/frames when/if I look for a buy...
Course it's doubtful that I'd get another rim brake bike, since I already have a boatload that will last to end of days...
Ride On
Yuri

Those dropouts look like they have been enlarged, either on purpose or from wear (too loose of a skewer). Those marks on the second pic also suggest that the axle is indeed shifting, but it shouldn't be even if the skewer is out. I just took these pics for comparison. Note the tighter clearances.
https://cimg2.ibsrv.net/gimg/bikefor...31aa30c1f0.jpg
https://cimg3.ibsrv.net/gimg/bikefor...f16c7d8a39.jpg

Yep, I have a 2007 Look 595. Rear dropouts are all carbon

In the pics that the OP posted, it almost looks as if the that’s a front axle in those larger rear dropouts. I mean it isn’t possible that a rear wheel was mistakenly assembled with a front axle is it?

Dan

What size of tires are you using?

You might benefit of simply reducing the tire size by one size. Especially if the son is fairly lightweight.

On one bike, I found a benefit of giving the drive side skewer nut a slight tug back before tightening down. Keeping the wheel centered, but just enough to pull the skewer shaft to back of the axle hole.

Could it be the wheel/spoke tension and just being flexy under load? Or the frame itself flexing?
Tried just bending the frame/wheel side to side while off the bike, using body weight and strength?

the dropouts are trashed

not uncommon on the Scott CR1 frame carbon dropouts

(google search brings up a number of related threads)

23mm tires, spokes tensioned and wheels true, cones adusted .
Dropouts do seem to have more clearance than I would expect.
I'm not sure this happens constantly. Skewers may just have been improperly adjusted.