This is a custom-built twin-turbocharged BMW R100 that was painstakingly built by the team over at Boxer Metal, a husband and wife run BMW motorcycle and sidecar shop based in Chico, California.

They first unveiled the bike at The One Motorcycle Show in Portland, Oregon in 2016, where it promptly won an award and enjoyed a weekend surrounded by crowds of stunned onlookers. Later that same year it was awarded 2nd place in the Custom Motorcycle Class at The Quail Motorcycle Gathering.

Fast Facts – The Twin-Turbo Boxer Metal BMW R100

  • This highly-unusual BMW R100 was built in 2016 by Chris and Rebecca Canterbury, the couple who own and operate Boxer Metal, a BMW specialist motorcycle workshop in California.
  • The BMW R100 has long been a popular choice for custom motorcycle builders, they’ve been converted into scramblers, cafe racers, flat trackers, retro adventure bikes and more, but this is the first time we’ve seen one quite like this.
  • The build began with just seven weeks to go before The One Motorcycle Show in Portland, and it was made all the more difficult by the fact that Chris and Rebecca had to not just build a custom bike, but build a custom twin-turbo, fuel-injected R100 hardtail that actually runs and is rideable.
  • Despite the long odds they succeeded in getting the bike ready in time, taking a prestigious award at the show and following it up with a hard fought 2nd place in the Custom Motorcycle Class at The Quail Motorcycle Gathering later in 2016.

A BMW R100 History Speedrun

The story of the BMW R100 begins in the mid-1970s when BMW Motorrad, the motorcycle division of the German automobile giant, sought to improve its lineup of air-cooled, horizontally-opposed twin-cylinder motorcycles. The R100 was introduced in 1976, replacing the R90 as the flagship model in BMW’s “R Series” model family.

BMW R100 RS Vintage Ad

Image DescriptionThe BMW R100 series of motorcycles were offered in a wide-array of different configurations and styles, including performance tourers like the R100 RS shown here, and the R100 GS – a Paris-Dakar Rally competitor. Image courtesy of BMW Motorrad.

At the heart of the R100 is BMW’s iconic air-cooled, 980cc, “Boxer” twin engine. This engine configuration, a hallmark of BMW motorcycles since the 1920s, provides good balance and smooth power delivery.

The layout of the engine, with the cylinders and heads out in clean airflow, provides excellent cooling and it avoids some of the problems encountered by transverse air-cooled V-twin engines, where the rear cylinder can overheat due to insufficient cooling air flow.

The R100’s engine was an evolution of its predecessor, the R90, with a displacement increase that boosted performance significantly. Not long after the release of the R100 aftermarket companies developed 1000cc upgrade kits for earlier BMW R series motorcycles, allowing them the same upgrade.

Like its predecessor, the R100 came equipped with a 5-speed transmission and shaft drive, which delivered power to the rear wheel without the required maintenance level as a chain final drive.

Twin-Turbo Boxer Metal BMW R100 11

Image DescriptionAs famous as the BMW R100 is, we’ve never seen one look like this before.

The R100 had a front disc brake and a rear drum, and its suspension included telescopic forks up front and twin shock absorbers at the rear initially, later in the model’s life the “Monolever” single-sided swing arm debuted, which was then followed by the “Paralever” single-sided swingarm later in the 1980s.

In 1996, after a remarkably successful 20 year production run, BMW discontinued the R100 series as it shifted focus towards its new generation of oil-cooled, multi-valve Boxer engines. The final edition of the R100, the R100R Mystic, was released in 1993 and produced until 1996, marking the end of an era.

Today the motorcycles in the BMW R100 model family remain some of the most popular in the company’s history, thanks to their combination of reliability, rideability, and mechanical simplicity.

The Twin-Turbo Boxer Metal BMW R100 Shown Here

There can be no doubt that this is one of the most unusual BMW R100 customs we’ve ever seen. The build process took under seven week amazingly, with Chris and Rebecca Canterbury of Boxer Metal in California creating it specifically for The One Motorcycle Show in Portland, Oregon.

Twin-Turbo Boxer Metal BMW R100 7

Image DescriptionEach side has its own Speed Daddy T3 turbo, wastegate, blowoff valve, and fuel injector. All of the exhaust pipe work is custom of course, as this isn’t the kind of set up you can buy off the shelf.

The build process began with the acquisition of a 1980 BMW R100. The teardown commenced and any parts not needed for the final bike were set aside. The original tubular steel frame was highly-modified, with the original swing arm rear end completely removed and a new custom hardtail welded into place.

A new seat was fabricated and joined with the rear fender, and a fuel tank from a Dnepr was sourced and given a gold candy-flake paint job with black pinstriping applied by Dennis Price. Up front the forks were rebuilt with new progressive springs, a new front brake caliper and rotor were also fitted, along with clip-on handlebars and rearset footpegs.

Of course, the true pièce de résistance of this build is that remarkable twin-turbocharged boxer twin.

A pair of Speed Daddy T3 turbos were acquired along with a MegaSquirt MicroSquirt system and electronic fuel injection to replace the original dual Bing carburetors. Fuel injection is widely preferred over carburetors due to the fact that it’s typically much easier to dial in in forced-induction applications.

Twin-Turbo Boxer Metal BMW R100 2

Image DescriptionUnlike the original this R100 is fitted with period-correct Brembo disc brakes front and back, given the engine configuration it must have seemed wise to give the bike as much stopping power as possible.

A new exhaust system was fabricated and one turbo was fitted to each side, fed directly by that side’s cylinder. There’s no intercooler used, the turbo blows its compressed charge directly into the cylinder, with fuel added along the way.

The completed bike is as eye-catching as it is unusual, and it remains a testament to the level of work Boxer Metal can turn out, even with a tight deadline. After its release in 2016 this bike lit up the custom motorcycle corner of the internet, with Pipeburn dedicating a full feature to it, which was then picked up by multiple other publishers.

The bike is now up for sale on Bring a Trailer out of Dayton, California, and it’s being sold directly from the collection of Boxer Metal. it comes with a custom-made Dehen jacket for the BMW Motorrad Award at the One Moto Show, literature featuring the bike, and a stand made for the bike. If you’d like to read more about it or place a bid you can visit the listing here.

Twin-Turbo Boxer Metal BMW R100 21 Twin-Turbo Boxer Metal BMW R100 20 Twin-Turbo Boxer Metal BMW R100 19 Twin-Turbo Boxer Metal BMW R100 18 Twin-Turbo Boxer Metal BMW R100 17 Twin-Turbo Boxer Metal BMW R100 16 Twin-Turbo Boxer Metal BMW R100 15 Twin-Turbo Boxer Metal BMW R100 14 Twin-Turbo Boxer Metal BMW R100 13 Twin-Turbo Boxer Metal BMW R100 12 Twin-Turbo Boxer Metal BMW R100 10 Twin-Turbo Boxer Metal BMW R100 9 Twin-Turbo Boxer Metal BMW R100 8 Twin-Turbo Boxer Metal BMW R100 6 Twin-Turbo Boxer Metal BMW R100 5 Twin-Turbo Boxer Metal BMW R100 4 Twin-Turbo Boxer Metal BMW R100 3

Images courtesy of Bring a Trailer and Boxer Metal

Published by Ben Branch -