My 256SL build

[Arraider]

hi guys i need some help, almost going crazy with the rear brake... 

I hope i can explain this as English is not my 1st language...my problem is the frame supports for the rear brake. they make some strange angle, if i unscrew both screws a little everything is fine, i spin the wheel and no problem, but as soon as i tight either screw the brake caliper starts to tilt and it gets a angle and with either screw or both screwed i cannot get the rotor to spin freely... anyone got this problem.

I tried, my mechanic tried and nothing...

[Arraider]

the supports for the brake caliper are crooked, the inside part is lower than the outside and the caliper gets angle... i did not deserve this...

i put a nylon washer i had just on the inside part of the supports (not on the srew, just on the outside and between the screw and the support), to "uncrooke", or to compensate the "crookness" and it bloody works, but i cannot see a solution for this OMG!

this is the result without any compensation


in the photo attached you can see the caliper crooked and like this there is no way i can ride the bike, the rotor scraches constantly the inside of the caliper, on the top on the outside and on the bottom on the inside.

the supports on the frame for the caliper are tilted for the inside, crooked, they are higher on the ouside then on the inside, when you fasten the screw it all goes weel until you get to the end and it forces the caliper and the face of the support to touch, the caliper starts to tilt to the inside and from there all goes wrong.

[outriding9800]

Hmm. Are u missing the cone washers?

[brmeyer135]

Interesting, glad you brought it here.
First, this is a known good caliper?
If so, do you have a dremel type tool with grinding wheel?
I would look to do something like that to get the angle needed.
Or, work with the seller.

[Carbon_Dude]

I would ask the frame seller to send you a dimensioned drawing of your frame so you can check and see if the caliper mounting bosses are the correct height.  Seems like there should be a dimension you could check, a distance from the rear axle line to the top of the caliper mounts.

[Arraider]

OUtriding, English is not my 1st language, but i googled cone washers and i have no idea what cone washers should i have or where to apply them?!

brmeyer135, yes it is a good caliper, it was mounted with success on 2 previous bikes, and when i removed it it was religiously stored. The rotor has no problem either i checked. I taught of doing something like that, but the inside angle is common to both screw supports (at least it's coherent i guess) and i don't know if i can level them without making thing worse (in reality worse is really hard as i cannot ride like this), but you guys get my point)

Carbon_Dude that's a very good idea, will definitely do that

i just had to go there after and look more into it, disbelieve i guess, and the rotor and the screw (just putting in the screw without the caliper) are not parallel. And if i just screw everything with the caliper and all, the rotor touches the inside of the caliper, and you can hear a screeching sound when you press the brakes because of the angle the caliper forces the rotor to bend. For me there is no doubt as to what is wrong

thanks to all  I have no idea what to do... i had everything mounted, it will be a pain to remove everything and send it back, and not feeling really good about starting to mess with the frame especially when it involves brakes, if it where something else....

[brmeyer135]

Now that you are saying that the screw is not in straight/parallel - that is a return to vendor to me...get some pictures and you should have no problem.

[Arraider]

yes, it's my best bet also.

I'm still gonna try somethings to relieve my conscience that i'm not crazy, try some other caliper and try some washer that are higher on one side then the other, but because of this i do not think they will work.

Anyone knows how this returns usually work with the Chinese vendors? Do they assume the freight charges both way?

my bad luck...

Just out of curiosity how can this happen, i have no idea what the construction process of a carbon frame involves?!

[outriding9800]

No problem...

I might have used the wrong term..

This is what I was thinking of... and I did not see them in your pic..

http://www.parktool.com/uploads/images/blog/repair_help/avid-hydro-672.jpg

[Arraider]

ok mine are shimano xt, they do not use them. 

[Vipassana]

Can the mount surfaces be sanded flatter so that the brake can sit flatter?  In wondering if the mount is correct but the final finishing level of paint/resin is uneven.

[Arraider]

yes vipssana it's a common suggested solution, the problem is that the place where the screw enters the frame is also tilted, i don't know if just sanding the surface will work

[Vipassana]

Ah, in that case you might be out of luck. 

[Arraider]

i guess this is the best way to show my problem, no words needed...

[MTB2223]

i guess this is the best way to show my problem, no words needed...

oh man, that doesn't look good.
Are you sure there isn't a problem in the dropouts ?
Otherwise, it's a production failure. I hope you can solve this problem without any costs.

It's now to XMIPlay to show how good their service is ...