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View Full Version : discbrakes help needed.

tuscanyswe
10-28-2008, 07:34 PM
I just built up my first set of wheels.

When they were done and i fitted the front wheel to the fork i realise that the rotor hit the discbrake adapter mount on the avid bb7. Meaning that the rotors can not be fitted into the pads since rotor somehow is located to close to the fork leg.

The part the rotor is hitting is not the pad or the caliper but its the actual post mount, so there is no way for me to use the side adjustment bolts on caliper since it wont even fit into it.

How can this be? the hub is a white industries m16 hub with standard 100mm axle and standard 6 bolt rotor.

The only thing i can think of is that somehow the brake adapter mount (wich is for avid bb7 160mm) somehow is to thick, but do these adapter mounts even come in different widths?

Any ideas?
gdw
10-28-2008, 08:02 PM
Who is the fork manufacturer? I believe that you mentioned that it is a ti fork in a previous post. How wide are the fork legs where the original disc tabs are? Can you post a picture of it showing the installed adapter and brake? Is it possible to install the Avid adapter on both the inner and outer sides of the original mounts? If it is mounted on the inside would moving it to the outside solve the problem?
40x14
10-28-2008, 10:23 PM
A photo would be very helpful.

Is it possible that the disc brake rotor is larger than what's meant to be used with that fork?

I know that rotors come in sizes 160mm, 180mm, 203mm (6, 7, 8 inch) maybe other diameters too.
Richard
10-29-2008, 06:00 AM
If the disc is too big, there are adapters for the caliper to make it all work. There are, as said, multiple disc sizes. One fork dimension. Find the adapter.
tuscanyswe
10-29-2008, 08:25 AM
sry no pics now, ill try to get one asap.

But the problem is not the rotor size, since rotor size only differs in the circle diameter.

And its not the fork that cant handle the rotor size, since its a mtb fork and the rotor is only 160. But yes as someone said it is a small manufacturers Titanium fork.

Suggestion of putting the actual adapter on the outside of the fork mounts wont work cause then the caliper wont reach the rotor even in the outer possition when mounted on the outside, plus its looks goofy :D

Is it completely out of the question to slim down the fork disc mounts? we are talking about 2mm or less, they are atleast 6mm thick to begin with.
gdw
10-29-2008, 09:22 AM
Contact the fork manufacturer and see what they recommend. You can't be the first owner to have had this problem.
40x14
10-29-2008, 10:40 AM
When you remove the pads, can you fit the rotor into the caliper?
tuscanyswe
10-29-2008, 11:18 AM
No.

the rotor hits the adapter for mounting the caliper, so pads or no pads make no difference.
Richard
10-29-2008, 11:31 AM
Have you tried a wheel that has worked on other disc equipped bikes? If I am reading correctly, the disc is not standing away from the hub far enough to clear the inner part of the caliper. If that is correct, whether it is a hub issue, spacer issue or fork issue is hard to figure. Or, is the disc assymetric -- only one side should be bolted to the hub and you have it reversed?
gdw
10-29-2008, 11:57 AM
Who made the fork? Are they a small operation or do they manufacture the forks in volume? Are you using an Avid rotor and CPS adapter or other aftermarket products?

It sounds like they attached the original ISO mounts too close to the inside of the fork legs for the adapter to work but we need photos to determine that.
tuscanyswe
10-29-2008, 01:41 PM
Iso mounts mounted to close to fork center sounds about right to me aswell, bike aint home right now so will have to get pics up tomorrow.

I like the idea of the rotors having one side only to fit to the hub unfortunetly i dont think this is the case. I will however double checkt, good thinking.
tuscanyswe
10-29-2008, 01:52 PM
Have you tried a wheel that has worked on other disc equipped bikes? If I am reading correctly, the disc is not standing away from the hub far enough to clear the inner part of the caliper. If that is correct, whether it is a hub issue, spacer issue or fork issue is hard to figure. Or, is the disc assymetric -- only one side should be bolted to the hub and you have it reversed?

No i dont have access to another disc wheel right now.
You understand the problem correctly but the rotor is actually to far out to fit into the caliper and not to close.
tuscanyswe
11-04-2008, 09:50 AM
Thx for help.

turns out the brake tabs on the fork were to thick so they needed to be grinded down and aligned properly. Had to be done by lbs so bike should be rdy by tomorrow evening.

It will be a weird but kewl bike, post a picture in gallery in a day or 2.