Originally Posted by
cycle_maven
In Sheldon's case, the bolt is perpendicular to the fork crown, and therefore is neutral to tightening or loosening when braking. Personally I wouldn't trust anything on my braking system that relied only on friction to hold it in place against the direction of the major force vector. But it's your bike...
The bolt being perpendicular or not depends on the angle of the surface of the crown and whether it is modified by spherical washers.
I just finished cannibalizing washers and such from the old brake to mount the new one at an angle, but without drilling the fork crown as suggested by AEO and I now have:
brake->anticup washer->cup washer->saddle washer->crown->antisaddle washer->cup washer->anticup washer->nut
This seems to give a good fit, but there's unfortunately not enough room on the bolt for a second nut to prevent the first from loosening, which is bad because this is the only nut holding things together (the front of the bolt is integrated to the brake arms). Also, unfortunately the impressive stack of washers weighs almost as much as the brake itself.
Originally Posted by
stausty
It really isn't going to work. Assuming you did get it all mounted in the fork - which is at least going to require curved, beveled washers on either side of the fork on the mounting bolt - braking force is going to torque the caliper backwards. When mounted correctly the braking force pushes the caliper pretty much straight back, parallel to the mounting bolt (and with two contact points on the fork). Here the force will be pushing and a significant angle on the one contact and before long you'll have a bent bolt, if not a hole ripped in the fork, a caliper jammed in your wheel, and a face that will be thankful for Percoset.
After reading your post I noticed that the mounting bolt from the old brake is bent in exactly the manner you describe. If what you say is true this would actually indicate that the braking force is pushing at an upward angle, in which case the angled mount would actually be the only safe option for exactly the reasons you give for it being more dangerous. In fact, looking at the pictures, it seems the root cause for both the torque and the reach/offset issue is actually the orientation of the braking surface and that the only thorough solution is to correct the angle of the mounting bolt to be tangent to that surface.
While I'm glad you pointed this out, it's a bit disconcerting as it now appears I'll be compromising safety if I
don't figure out a way to make the unconventional angled mount work.
Originally Posted by
Bob Barker
Just for the sake of knowing - why the long "spacer" between the caliper and the fork? Did your old brake have the same arrangement? I've just never had one like that.
If you could cut that down you might acheive a two-point mount w/o drilling the fork.
Not sure why, but the other brake has a similar spacer. It seems to ensure that the spring has enough clearance to operate without having interference from the fork.
In light of the washer difficulties and revelation above I might actually try filing this to agree with angled mount. However I'll have to be careful because on this particular brake that's where the CNC magic attaches the mounting bolt to the brake arms without any nuts.
Thanks for your input everyone. Does anyone have any more ideas?