This is from the site Bring a Trailer (https://bringatrailer.com/) ...
This custom BMW motorcycle is one of two cafe racers recently designed and constructed by the seller’s workshop, Upcycle Garage. Finished in two-tone green with a leather solo seat, the bike started out as a 1988 R100RT with a monolever swingarm. It now features an R90S-style quarter fairing, a Kawasaki ZX-6R front end, custom rear sets, and LED lighting. The 980cc opposed-twin is paired with a five-speed gearbox and equipped with a high-mount, 2-into-1 exhaust system. Modern electronics and instrumentation were sourced from motogadget, including their motoscope pro display and m.unit digital control panel. This custom R100 is now being offered with a clear California title.
AirTech Streamlining supplied the R90S-style fairing, which the seller re-profiled and modified with a single, offset headlamp. The two-tone seafoam green finish features white accent striping. Black powder coat has been applied to the frame and swingarm, and a stitched leather solo seat is supported by a custom subframe with LED lights integrated below. Front turn indicators are positioned on the handlebars, and the BMW roundels have been deleted from the fuel tank.
The 18” factory front wheel and twin brake rotors have been adapted to an inverted fork sourced from a donor 2007 Kawasaki ZX-6R with Nissin radial calipers. Rider controls include low-mount, clip-on handlebars and custom rear sets. An upgraded rear shock with a remote reservoir was sourced from Öhlins.
A motogadget m-unit replaces a traditional fuse panel, and a Shorai lithium-ion battery is located below the gearbox. Instrumentation is provided by a motoscope pro digital multifunction display, also from motogadget and secured to the upper triple tree.
The 980cc opposed-twin is paired with a five-speed gearbox and enclosed driveshaft. A streamlined cover from BMW-Bayer replaces the factory top cover and airbox, while the engine and gearbox cases have been painted gloss black. The 2-into-1 stainless headers are designed to hug the engine and are constructed with TIG-welded pie sections. A single Akrapovič silencer is mounted below the seat.