I remember the time, just a few years ago, when it was almost impossible to find in the US a sprocket drive kit where the brake pinches directly on the chain sprocket. You had to order it from Tolle in Sweden. Then Pat Kennedy imported some, then Exile Cycles & HHI in the US made their own, and with the old school style in full swing you have now the choice between almost 10 manufacturers. When I stopped at the V-Twin Expo booth of 3 Guyz Customs, I saw their new system and checked what they had to offer. First, their setup can be ordered for either 530 or 630 O-Ring chain. Second, they offer a double-acting true opposing piston caliper design and use Lyndall racing “Z” pads for a superior coefficient of friction. Third, they propose a full kit (in both left & right side transmission) including not only the brake, sprockets, anchors but also the chain (530 or 630) and transmission sprockets in 21, 22, and 23 tooth with .310", .500" and .820" offset. One source for all your Sprocket Brake Drive components is always good both pros and garage builders. 3 Guyz Customs.