SRAM patent proposes "universal brake mount" designs to eliminate disc brake rub and "improve braking performance"

It looks like the braking forces are transmitted through a pin or bolt (item 430) between points 422 and 426 on the exploded view diagram - very much like a conventional disc mount in terms of loads applied to the frame. No need for the big nut to do anything more than stop the brake falling off when you take the through axle out.

The whole setup looks quite sensible to me. No idea if it will catch on of course.

I'm sure they have checked everything better than I could ever do, but this axle opening 426 in the frame might add more torsion and shear than compression (as it does on the traditional system). And only half of the (seat) stay width is taking all these forces (at least on this picture).

Which doesn't sound great for carbon frames? in this figure it's fixed on a seat stay, these are usually much lighter than chainstays. Of course they could be designed differently.

If the bolt 424 or 430 allow to laterally ajust the caliper to the rotor (a very small amount of course else the longitudinal alignment would suffer), that would be better than the actual system where the 2 main bolts need to be loosened, then tightened after trial and error.

That said the main cause of squeaks is usually bent rotors, which is of course not addressed by that system. When I replace a set of wheel, the rotors usually come into place after a few kilometers, so although they might squeak in the beginning, I don't need shims or adjustments but only some patience...

I think it will help - the second fixing point is a sleeve, and the bracket then clamps to it. This means the bracket can still define itself axially, even if the chain stay is not in the perfect position.

Agreed it is not as pretty as engineering the chainstay, but maybe it is very difficult (=more expensive) to get the proper tolerance on a chainstay  which is designed to flex. 

Well I guess in some ways it could be unisversal to bikes that don't have disc brake mounts. But none of my rim brake frames have through axles, so it won't work as a retrofit option for them.

I can see it has some potential benefits, but counter to the the iead you spend less time setting up your brakes, looking at this your brake caliper comes off every time you remove your wheel to clean the bike, fix a flat etc. which sounds inconvenient to say the least.

There's no way to retrofit this without milling, drilling and reinforcing a frame...

Calipers wouldn't come off when removing the wheel - you'd just remove the through-axle and then the wheel.

SimoninSpalding wrote:

Well I guess in some ways it could be unisversal to bikes that don't have disc brake mounts. But none of my rim brake frames have through axles, so it won't work as a retrofit option for them

If your old bike is made of steel  you can convert to disk, just find an experienced metalworker, give him a mocked up example and ask him to make it in metal for the rear and buy a new disk fork for the front. See attached picture of my vintage tandem lockdown project. The end result works brilliantly!

Thats a lovely job.  Kudos to the welder, especially if they aren't a frame builder

Worth noting that a good frame builder will have a jig for welding on disc brake tabs.

The guy restores classic cars and seems to know his stuff. He also welded on a derailleur hanger made out of a bolt on one and it must be well aligned because the gear change is perfect, even with the extra long cables! I needed this to have the wheel at the rear of the dropout so that braking forces didn't move it, the device you can see attached to the quick release is called a hurdy gurdy and resists the chain tension.

and a picture of the full bike, it has since been upgraded with drop bars at the back.