I don't know whether anyone else has had this problem but the friction material came off my rear brake shoes causing the brake to bind, luckily not lock up! It happened suddenly and there was no warning. The brakes were well adjusted, not binding and the shoes still had 4mm of material on them. I bought them about two years ago. The bike lives outside and is used all year round. I can only assume that dampness has corroded them or it is a bad batch of shoes. Anyway, it is worth checking these things because the Honda ones are no longer available and the aftermarket ones are clearly not as good as they should be.