When I first started racing the Seeley 850, I had one Locheed AP calliper with a chromed disc off a Suzuki GS1000. It was nowhere near enough brake. I ended-up with two Suzuki steel discs with very old asbestos compound pads. I tried racing pads, but they never seemed to work well enough. My master cylinder was designed to operate one calliper - it operates two. The brake is excellent - one finger operation, and needs to be like that, if someone stupid brakes in front of me.