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Howdy everyone, I have a 18" K-bike front mag wheel I've used occasionally on the front of my R100GS. Makes it a quicker more fun street/twistie bike. I have to shim the brake caliper closer to the wheel to get the brake rotor to be centered in the caliper, but otherwise it is an easy swap.

I recently acquired a nice R100R front wheel which matches the spoked rear wheel on the GS and am trying to do the same thing. However, shimming the caliper closer to the wheel makes it interfere with the spokes (the mag K-bike wheel is narrower at that point and doesn't touch). I'm planning on shimming the DISK closer to the caliper instead, but thought I'd check if anyone has suggestions.

Thanks,

Don

This won't be much help, but the R100R used the K75S front end while the R100GS used its own different design. I don't remember if there was any difference in the calipers, but that might be something to ponder. Never heard of a disc being shimmed, but that doesn't mean that it won't work. Keep us posted!

I've been trying to find the best way to put conventional calipers on my R75/6 and have run into the same problem with caliper to spoke clearance. I think there are two way she: 1. Find a narrower hub, e.g. a GS hub (have to change the bearings for the axle size). 2. Run a much larger disk, probably around 13", and make adapters for the calipers. 3. New front end (e.g. Jap bike).

Keep us apprised.

Abstruse1 wrote:I've been trying to find the best way to put conventional calipers on my R75/6 and have run into the same problem with caliper to spoke clearance. I think there are two way she: 1. Find a narrower hub, e.g. a GS hub (have to change the bearings for the axle size). 2. Run a much larger disk, probably around 13", and make adapters for the calipers. 3. New front end (e.g. Jap bike).

Keep us apprised.

There is one other "solution," but I don't know if it would work in this case. I know of some bikes where the spokes interference with a 4 pot caliper is just close enough that you can grind away some of the caliper body on a big belt sander, and it fits. Obviously, this is never the best solution, but it is A solution for some situations.

Interference is too great in my case.

My G/S came with a large aftermarket disk shimmed / out till it just about touched the fork leg , ans a four pot caliper which was also shimmed over to suit the disk.And to miss the spokes.

Worked OK till a tire fitter removed the caliper when removing the wheel and forgot to tighten the bolts -----.
The fancy four pot sprung a leak and I replaced the stock two pot, worked just as well if not better than the four pot - as someone pointed out recently there is more to brake performance than the items which seen to come up on most discussions - pad area comes into it too - modern sintered pads don't mind a bit heat and actually work better at temps which would make organic fade.