I have been racing my B50 for 7 years and one issue I always had was front brake fade with the original drum. The brake works well but on short tight tracks I would get fade even with better pads.
So, a few years ago I purchased a suzuki dls brake at a local swap meet with hopes of installing it on my B50. Well, this winter I finally got working on the conversion. This turned out to be a lot more work than predicted but I'm pretty happy with the results. Thanks to Ray Roberts for the machining help with the forks and drum. The big brake should slow down the little B50 .