The RCB1000 was the in-between bike for SOHC and DOHC that did very well in Endurance road races in the late 70s. SOHC bottom cases, geared primary, with a DOHC head. There isnt too much info available on the net, but a google search will have a good page ont the history of the bike. If you look at all the pics, you can see the progression of the DOHC heads that they used through the years. I would like to build a replica, so if anyone else has more info on this bike, I would greatly appreciate it.