Hi all, I have a chinese carbon fork that is drilled such that the brake does not sit flush with the fork surface. I am currently using two spherical washers to get even contact between two, but am wondering if there is a better solution that doesn't require me torquing the recessed nut really hard to prevent rotation at the bolt. I did some Googling and found out about beveled washers, but am not sure if they will work better than what I have now, since I don't even know if they are the correct angle. Does anyone else have experience with this problem?

Thanks!

Toothy star washers, to Bite into the fork front surface, & back of the brake itself, then what happens with the nut on the other side matters less.

No clue about your fork choice, in specifics , perhaps that was not the best.

You didn't describe the specific issue. If the fork crown has a flat face the brake should sit squarely and flat on it. OTOH- some (mostly older) forks have curved faces and so need a flat to curved washer to match the shapes correctly.

Offhand, I don't know of any curved face carbon forks, and would be a bit surprised if anybody made one. So the brake hole should be square to the flat face and brake should sit squarely against it without help. You certainly wouldn't want anything like wedges since that will force the brake to the side and cause other issues. If the face is basically flat, and square, but not flat enough, you can return it as defective or correct it. Buy a stainless steel flat washer. Put some body filler on it and put it on the brake bolt filler side to the fork. Tighten to near riding spec, allow it to cure completely, then loosen, center and retighten the brake and you'll be good to go.

Why, exactly, won't the brake's back side not sit flush with the crown? Interference with a bearing race? Shaping of the crown/blades? This is where a photo really helps us understand the details.

Most current brakes are supplied with a toothed anti rotation washer and/or a smooth spacer or two. The brake manufacturer doesn't know which fork their brake is going on. Some forks come with the same and/or mounting bolt nuts of different lengths to accommodate their specific dimensions.

As you seem to grasp, the need for a well secured ft brake and it's not pivoting freely about is a strong one. Andy.

Ah. I knew I forgot something. Pictures! Sorry about about that.

IDK what you wish it were... The Brake Bolt holes are drilled Perpendicular to the steering tube, then you adjust the brake pads to hit the rim

You are correct; the brake bolt hole IS drilled perpendicular to the steer tube--but the surface of the fork itself is not perpendicular to that drilling.

File a flat spot in the front of the fork then . or scarf a rough surface and bond a filed wedge washer down solid with more Epoxy.

you might try a plastic or nylon washer (ACE is the place ), it may deform enough to help. maybe cut it in half and apply a file to it. of course it may deform under braking pressure too... or you might take a file to the lower half of that collar (looks like it might be metal, or even some kind of nut painted black, maybe it could be removed) on the front of the brake hole.

the last pic shows the problem well. someone should come up with a clever solution

Something is seriously F***ed up.

I can't see it in the photo, please indicate with a mark of some kind where the nut is on the back of the fork. Ir is this some sort of a blind mount? and if so why don't you let the brake orient to the face, as it naturally would.

BTW- if the nut is in the back of the fork and lined up with the bolt as it is in the photo, the fork is defective.

A correctly drilled fork will be drilled square to the face. (no exceptions) The position of the exit hole in the back will conform this or prove otherwise. Gauging by the photo, I'd expect the exit hole to be much lower, down near the apex of the curve in the fork or even below that.

Right, I'm just afraid of cracking the carbon by tightening that recessed nut too much. I figured I was helping spread the load evenly by using those spherical washers.

The nut is installed.

Yes, but I can't see it in the photo, and can't use it as a guide to help identify what may be wrong.

Again, so you can draw your own conclusions. The bolt should not be horizontal or perpendicular to the steering axis, it should be perpendicular to the fork's face, or tilted down about 17° from the steering axis. So if the nut is on and it's the same height in back and front the fork is drilled wrong. (unless it's of some sort of unique design).

Used a post-it note to mark the center of the hole in the back. Looks like it's incorrect, then?

Yes, that tells me what I needed to know. Unless the fork has some kind of removable insert in front that can create a face square to your red line, the fork is 100% for sure defective.

If returning it is an option, that's your best course. If not, you need to build up a face in front that's square to the line, but that may mean other problems because you'll note that the brake is set at an angle which brings the shoes into an overlap with the blades.

Alright, I'll see if return is an option. Thanks a lot guys!

It would be simple project for a home machinist to create an angled spacer or to mill a flat on the fork that is perpendicular to the bolt hole. I get a lot of use out of my lathe and mill.

Yes, there are ways to make this work, but as I said, there's also the issue ob brake shoe/blade clearance.

Even if every issue can be addressed, and they can, there's another issue that can't be addressed.

This is a no name carbon fork. Given the nature of the error, I'd have plenty of trouble trusting this manufacturer. It might be OK for another part, but forks are things that you have to have 100% blind faith in, and this doesn't make the cut. If I couldn't get my dough back, I'd trash it on general principles.

Is the crown aluminum or carbon? If it's aluminum you might have some room to mill it, if it's carbon I'd say to make an epoxy wedge.

All carbon. I have seen other forks that seemed to have a milled surface at the brake hole....