Hi,

I work for a superbike race team and in the past we have modified swingarms so that the caliper mounts of a billet chain adjuster block with drop down brackets to mount the caliper. Now with after market wheels maybe they had a problem with the disc hitting on the standard caliper slider/block. As a result they removed it......

I have a friend who worked gp 250's, I'll ask him.....he may be able to confirm my theory.

Hope this helps

Regards Drew

P.s I'll take a picture of our current caliper mount to show you what I mean.