Yep had the same problem on mine - I don't think its the stub axle that it fouls on, I think it's the brake caliper mounting plate.

I went for a very low tech approx and trimmed a smidge of the corners of the inner pad. Done about 3000 miles will no ill effects....

When I need to replace the pads, I'll probably remove the caliper and trim down the mounting plate.I think a chamfer should do the trick..

"Y mae dafad ddu ym mhob praidd"
1972 4/4, 1981 MGBGT, 1984 FLHT1340, 1980 XLH1000, 1990 ZX10