Top 3 BMW R100 Cafe Racer Builds

When building a cafe racer, one should prioritize its performance rather than its appearance. Café racers should be capable of racing at high speed over short distances. This article discusses the top BMW R100 café racer builds with a great blend of performance, quality, and finishing.

The BMW R100 was launched in 1976 and remained in production till 1996. It comes in different variants, including the RT, GS, CS, RS, TC, TIC, R, S, and T. This motorcycle is also known as the “Slash 7 Airhead” because of its big head fairing. The BMW R100 is powered by a 980 cc four-stroke boxer engine and equipped with a five-speed gearbox.

The BMW R100’s fairings and seat cowl are the heaviest parts. By removing the fairings and seat cowl, this motorcycle’s weight becomes greatly reduced. The BMW R100’s frame serves as a decent base for building a café racer.

Bill Costello is a well-known older motorcycle builder. Costello previously rebuilt a BMW R50 as a tribute to his father, with this motorcycle making it to the cover page of three top magazines. Because of his work, Costello was invited to Germany to meet BMW’s top-ranked engineers.

While Costello was in the spotlight, people kept asking about his next project. He then decided to modify a BMW R100RT to build a café racer that would eventually become Costello’s daily commuter.

Bill Costello’s BMW R100RT café racer build was an urban-style motorcycle that could be used for daily commutes.

While building the BMW R100RT café racer, Costello stated that all he wanted was a decent motorcycle that was stylish and powerful. While building the café racer, he could not improve the engine’s power output. The reason why Costello chose the BMW R100RT was that it could produce a decent horsepower of 70 hp.

Costello reduced the BMW R100RT Café Racer’s wet weight from 238.14 kg to 195 kg. Due to the reduced weight, Race Tech forks, gold-valve emulators, and Works performance shocks, the handling of this café racer build was improved.

A small lithium-ion battery is positioned under the tail cowl. There is also room for a toolkit under the seat as well. It is possible for a rider to mount a phone on the handlebars in case you need a GPS to help with navigation.

This café rider build was fitted with spoked wheels and Avon tubeless tires from Woody’s Wheel Works. Clip-on handlebars were used instead of a one-piece handlebar. Side mirrors are mounted at the ends and a small, modern display meter is positioned at the center of the front fork.

The BMW logo can be seen on the fuel tank, tail cowl, and bracket connected to the front fork. The license plate holder is mounted on the side right beside the rear shock. Two mufflers are installed on both sides of the café racer. Costello plans to further modify the BMW R100RT café racer by replacing the suspensions with softer ones.

The Story of the BMW R100RT Cafe Racer Build by Bill Costello (Video Link)

Customizing and rebuilding a motorcycle can be expensive. A builder is expected to create a café racer that balances its weight, looks, and performance. 

One of the most well-known and stylish custom BMW R100 café racers is the Boxer Twins by Johnny Nguyen, the owner of Upcycle Garage. The Boxer Twins are two motorcycles that have similar appearances yet different characteristics. They were the 1988 BMW R100RT and the 1982 BMW R100RS.

The Boxer Twins share a few features, like the engines, velocity stacks, pie-cut-shaped stainless steel mufflers, and vintage-style valve covers.

The major difference between the Boxer Twins is that a two-into-one muffler is installed on the right side of the BMW R100RS café racer, while a slip-on exhaust is installed below the seat of the BMW R100RT café racer.

The BMW R90S’s redesigned head fairings with a windscreen and a small-sized headlight were installed in both Boxer Twins. The air boxes were removed from the engine and new glossy Bayer engine covers were installed.

The BMW R100RT and R100RS’s suspensions were very different. The BMW R100RT was equipped with a mono-lever system, while the BMW R100RS was equipped with a twin-shock in the rear.

Nguyen built a new suspension setup and sub-frames for the Boxer Twins. The new Ohlins shock was installed in the BMW R100RT Café Racer build and the twin shock was replaced with a mono-shock in the BMW R100RS Café Racer build.

For the BMW R100RT Café Racer build, Nguyen fitted it with Kawasaki ZX-6R forks, brake rotors, and front wheel. Whereas, the BMW R100RS Café Racer was fitted with Suzuki GSX-R1000 suspenders. Small display meters were installed on the bracket connecting the front forks of both the café racers.

The Story of the BMW R100 Boxer Twins Cafe Racers Build by Upcycle Garage (Video Link)

Building custom motorcycles is often considered a part-time job. However, some companies specialize in building whole production lines of custom motorcycle models. One such motorcycle company is WalzWerk. They build almost every type of motorcycle, with the BMW being their most popular customizable brand. WalzWerk also builds one special edition every year to pay tribute to an older motorcycle.

For the special edition, WalzWerk decided to use a 1989 BMW R100RS as a base. The company named this special edition BMW R100RS Café Racer build, “Monza.”

The Monza’s weight is 50 kg less than the original BMW R100RS, weighing a total of 168 kg. WalzWerk decided to upgrade the engine by installing a new balanced crankshaft, pistons, and bigger valves. The 980 cc boxer engine was overhauled so that it could work for at least a decade. The upgraded engine also had its maximum horsepower increased to 70 hp.

This BMW R100RS Café Racer starts due to its electronic ignition. Two stylish SC-Project mufflers were installed on each side. These mufflers are equipped with dB absorbers to reduce the noise coming from the silencers. WalzWerk provides its own components for the build rather than using parts from other motorcycle brands.

The main frame was fitted with replacement parts, while the rear end was completely rebuilt. A comfortable seat with a hump towards the rear was installed on the Monza.

The Monza’s back suspension was fully replaced by an adjustable mono-shock and the front suspension became reduced in size by 120 mm. The front suspension was installed with new dampers and progressive fork springs. The café rider build was fitted with Shinko 270 Super Classic tires and yellow 18-inch wheels.

The BMW R100RS Café Racer build came with clip-on handlebars, a tiny gauge in the middle, and side mirrors at the ends. The Monza had Yamaha TZ250 GP fairings and a round headlight.

The Story of the BMW R100 Cafe Racer Build by WalzWerk (Video Link)

The BMW R100 is a popular motorcycle base for building a café racer. This motorcycle produces adequate horsepower and has comfortable ergonomics. The quality of a café racer build depends on how much money and effort the builder puts into building it. Most popular café racer builds are those that are built by well-known companies. Also, customer input is important when determining the ideal qualities of a café racer build.

Café racers can also be used for light touring if equipped with different LUGGAGE options available at Viking Bags. The luggage options include SADDLEBAGS, TANK BAGS, and TAIL BAGS.