Only thing that I can think to do is to thread 2 or more nuts onto the brake boss threads and then tighten them together with high torque. Then grip this pair of nuts with a spanner and try to undo to the brake caliper bolt.
...or grip the brake boss bolt in an axle vice with soft jaws or an inner tube as protection.
Only thing that I can think to do is to thread 2 or more nuts onto the brake boss threads and then tighten them together with high torque. Then grip this pair of nuts with a spanner and try to undo to the brake caliper bolt.
...or grip the brake boss bolt in an axle vice with soft jaws or an inner tube as protection.