Along with the Viragos the BMW have become a common base for a lot of bike builders. I think the engine's simplistic shape has a lot to do with this. It gives the bike a low down bulk to the overall look.
Custom shop La Corona Motorcycles out of Barcelona have done an amazing job with this R100RS. Stripping everything down to the bare minimum and adding some classy modern touches to it.
The full specs are:
Deposit: Kawasaki kz750
Chassis: swingarm and forks as standard.
Faro: Scrambler grid
Handlebar: Dirt track
Speedometer: Mini 60 mm
Lighting Controls: integrated ISR handles
Grips: Classic black
Tires: Standard, reinforced front
Tires: Firestone ANS Military 1/5
Front brake: Standard
Front brake calipers: Standard
Front brake pump: Standard
Seat: motorcycles crown
Escapes: The crown motorcycles
Fender, taillight, battery box, and painting:
The crown motorcycles
Toolbox: The crown motorcycles, available at our store.
All photos taken from the La Corona motorcycles website