Brake Mount Facing

huggy_bizzle

Ok, so I've had these Rockshox XC32's for about 3 years now, I got Halfords to fit them to my second-hand Carrera Kraken and for a while, they seemed fine.

Since then, I've been learning more and more about the mechanics of a bike, buying new parts and fitting them myself. When I upgraded the wheels, particularly the rotors, I noticed that the brake mounts on my forks weren't faced correctly. It was almost like they had a burred edge to left side of the mounts that kept the calliper true to the rotors.

This gradually deteriorated as I was finding it harder to align the brake. I would set the calliper up, so that it would only slightly rub against the rotor (you could hear the rubbing noise when I was riding it). My Deore M615 front brake felt spongy too. At one point I did think the brake needed bleeding, I did this but to no effect, I fitted a new brake but that was the same! I also upgraded my 160mm rotors to 180mm in the hope that I would have more play in adjustment, still no luck.

Stupidly, one night after trying time and time again to align the brake, using the techniques I found by watching videos online, lost my cool and over tightened the bolts, damaging the threads inside.

I had a friend of mine fit Heli coils, he did a great job, but without me asking, he faced the post mounts. He wouldn't have used a proper tool like Park Tools DT-5.2 because he is an engineer and not a bike mechanic. He tells me he only lightly faced them but now when I fit a calliper to it, it's even harder to align, practically impossible.

Needless to say I've now replaced the forks with a pair of Rockshox Reba's and whilst I was at it, bought a second-hand Cube Reaction GTC Pro carbon frame and I've got to say, it's very nice bike. It has all new parts, that I’ve bought over the last 3 years, nothing from the Carrera Kraken that I bought from a friend, has survived. And the brake that previously felt spongy is now perfect.

I guess what I am asking is, what should I do? I contacted 'TFTuned' to see if they could face the brake mounts, unfortunately, this isn't a service they offer, they did tell me however, to find a good local bike shop that could help. I live in the south and don't have many options. I'm happy to send them to be worked on. I've looked at prices for the tool to do it myself, but I just cannot warrant the price as they are more expensive than the forks themselves. I suppose I could gamble and try face them myself with belt sander we have a work, but that could be risky.

Eventually, I would like to fit these forks to my girlfriend’s bike as they are better than the ones that came with her Carrera Vengeance.

I'm very interested in hearing your thoughts, any advice on this would be very much appreciated.

Thank you.

larkim

Don't most brake fixings use those rounded washers that allow for maximum adjustment so that the angle can be adjusted? If you've not got those in place, I'd have thought they would be aprt of a solution. I could be talking rubbish though!

cooldad

I've been through dozens of forks, and never needed to faff, neither has anyone I know.

So either what larkim said or user error.

The Rookie

The hint the mount needed facing would come from the fact that the pads were wearing at an angle (inside edge to outside edge) any other issue AT ALL has nothing to do with facing but something known as 'doing it right'.

Sounds like you simply didn't know how to fix the issue you had and unfortunately faffing with disc brakes without knowledge is a sure fire way to make them worse.

huggy_bizzle

Thanks for the replies guys, they are very much appreciated.

@larkim: Are those conical washers you are talking about? Don't they sit between the bolt head and the brake mount? Like the image below:



That wouldn't give me any adjustment (angle wise) to the caliper itself.

The bike I would be installing the fork to only has 160mm rotors. I wouldn't need any adapters, like the image below:



So if I were to add washers, particularly like the ones in the 1st image image, wouldn’t I be pushing the calliper and brake pads, away from the rotor?

I do think that these forks could have been faulty from new. My replacement forks have been faced correctly by the manufacturers and fitting the brakes is a doddle.

Perhaps I should try the installing the old fork on my girlfriends bike and see what happens, she will be using mechanical brakes so it may be ok.

The Rookie

You can't use conical washers as they will space the calliper out into the wrong position.

If you couldn't sort the alignment before, it suggests you need to learn how to do it and there is probably nothing wrong with the hardware at all?

larkim

I've seen (admittedly only limited experience) calipers mounted with a conical washer either side of the caliper, more like this. https://goo.gl/images/h5sNYT

Perhaps I've just seen incorrect mounting! Having just checked the manual on Shimano's site for the brakes I've got, it would seem they expect them just on the bolt side, not the facing side, so I accept my assertion might have been incorrect!

The Rookie

Older Avids were meant to be mounted like that and the mounting legs on the calliper were positioned for that, Shimano aren't and you'll screw it up if you use them.

larkim

That could explain it as the first set of disc brakes I used were Avid BB5