Running XT Caliper / XTR 160 Rotor on a Cotic Simple and having issues with the rear wheel pulling under heavy braking. The tyre pulls until the tyre rubs on the inside of the chain stay.
I have a On-One chain tug on the chain side.
Any ideas?

Chain Tug on the other side. Nutted hub or do your skewer up tighter.

Was trying to avoid the twin chain tug and nutted hub/axle as I use the single speed for racing.
Skewer is super tight at moment and takes some force to close it. It is marking the paint when moving.

A chain tug on non drive side will do nothing to stop this: its the leverage of the brake pushing the axle backwards not forwards, which is all the chain tug will pull against. (try looseing the qr a smidge and you will see this start to happen if you just rock the bike back and forth).

This is why slotty dropout on-ones have disc mount inside the rear triangle (there is some blurb somewhere on the website about this), some frames have the whole dropouts slide forward and a vertical dropout within this assembly, and some have eccentric bottom brackets and normal dropouts. Was never really an issue before disc brakes hence horizontal dropouts being the norm for old mtb's, and all bmx/track/fixes etc.

Only solution for this arrangment (ie horizontal dropouts and disc tabs on seat stay) is to do rear axle up much tighter. I had a jump/fun bike (commencal maxmax) -it was fine with a nutted axle done up nice and tight and I was always on the brakes on it. 😳

I use similar to this for the rear wheel on my Simple – not sure of which brand I use but make sure you get one wide enough to take into account the thickness of the rear drop outs.

Find I can tighten it up more than a skewer. Not sure how this fits in with racing if you're wanting a quick rear wheel change but it should be lighter than a Q/R.

Oh dear I have just bought a simple frame and I run shimano saint brakes.

That would answer the question as to why my Genesis iO has a bolt up rear

Nutted/bolt through axle is the way! QRs don't seem to be able to get tight enough without risking snapping the skewer.

…and if you are racing, tape this to your seatpost and if you can't fix it with that then start getting spanners out… In my experience a bolt-up axle is only a tiny bit more faff than the chain tug you must already have on the drive side, so puncturing in a race is always going to be bit of a mare!

Thanks for the help guys. Will try one of the hex key ones.

I'll be setting up my simple in the next week or so. I have pro 2 hubs with a quick release. What should I swap them for any links? plus I'll need chain tugs.

I use a hope ss hub on my simple with bolts. Never had a problem so bolts are the way to go to make sure the hub is secure. I don't actually think it takes that much longer to get the wheel out.

One thing you might want to try is moving the caliper on the slots. There does seem to be a certain position of caliper and axle in the frame end that makes this worse. If you can swing the caliper forwards and upwards at all, i.e. get the top brake bolt as high up the slot as possible without fouling the caliper, you'll move the ejection loads downwards rather than backwards so you'll have less load in the system. If you can't get it very far forward due to your gear ratio, maybe try getting a half link and getting the axle as far forward as possible.

Also, one thing that really works is serated washers under the QR to bite into the frame. This is the main reason the Hope SS hubs work so well, because the bolt are aggressively serated under the head.

Hope it gets sorted.

Hope bolt-up hub here as well. Nice big gripper washers thingies come with it.

dont know what QR you are using but i always use a shimano one in my ss setups. 😀

Oh, should add that I have the wheel as far forward as possible using a half-link. I only did that because it looks better, didn't realize it had practical advantages as well.

Some QRs stretch far too easily as well. Had to dump a non-brand one for a Shimano one on my road bike with track ends.

Okay so can I buy the hope bolt up for my pro 2, I'll have a look on CRC. Also cy if your reading can I buy some tensioning bolts as my frame did not come with any.

I have Hope SS hubs (bolt) now which never move.

DT Swiss RWS worked really well on my old QR set up.

The tension screws are just standard M4 x 40 with a spanner head on them. Don't get allen key heads as they're really hard to access. Spanner flats let you get at them from the side. We don't have any in stock as we stopped using them for the final run of Simples and supplied tugs instead as it worked better for longer.

I have just this second had the QR (shimano) fail (the thread stripped) and left me needing to push the bike to the LBS for a cheap replacement, i did see a link yesterday for fire eye bikes that do a chain tug system that stops movement each way on the axle, this may cure the problem although to be fair bolted hubs seem quite a good way forward.

Having sheared one of my allen-headed tension screws leaving the remainder buried in the drop out, I can confirm that hex-headed will be far easier to access!

'simple'

sounds quite the opposite to me.

I should also point out that I'm a ham-fisted idiot at times…

'simple'

sounds quite the opposite to me.

😆