Topic: Brake rotor mounting theory question

[754]

 I am  mounting 2 piston calipers to 750  K hub with floating rotors.
 Is there any advantage to rotor position ie closer to fork leg, or closer to wheelcenter, this is assuming caliper clears the spokes. Hat to make spacers needlessly.
 Any thoughts on this.?

[krusty]

Came across this on a Laverda forum

"I don't think it has so much to do with getting the calipers closer to the centre of mass of the bike, rather than getting them closer to the centre of the steering axis (which is behind the fork legs). That reduces the moment of inertia of the steering system about the steering axis, making the steering more responsive to rider input.
It also changes the natural frequency of steering oscillation, so may be beneficial if you're looking to eliminate any tank slapping tendency.
Someone reported earlier (after having just done the modification) that it also reduced the tendency of his bike to stand up and run wide when braking in a turn. I haven't quite figured out the physics of why that should be so, but it's certainly a desirable side effect."

http://www.laverdaforum.com/forum/index.php?topic=85726.30

[krusty]

Sorry 754 I misunderstood the question thinking caliper not rotors (oldtimers). I re read it after posting. Interesting comment anyway.

[754]

 I meant rotors, the calipers are single acting 2 piston so they have room to the spokes, and can bolt off easy..
 Calipers are behind legs. left rotor is around 8mm from forkleg, I think the second rotor will need spacer to even it up, but cant see adding a spacer if not really needed.

[bwaller]

Hey Frank, this is hardly from an engineering perspective, but I expect if you have a single rotor, then closest to wheel center makes sense. In the case of twin rotors then it's probably best to be evenly spaced from center. 

[simon#42]

i would try to get the disc as close to the fork leg as i could if only to get the discs and calipers out into the fresh air [ not shrouded by the front rim and tyre ]