Mandrill Garage Bonneville T100

Beijing Bonnie – Mandrill Garage Triumph T100

Despite the clear improvements and benefits of the newer water-cooled models, the air-cooled Triumph Bonneville T100 is destined to be a classic. When it was unveiled in 2000 it marked the return of the Bonneville after a 15-year hiatus. Despite its no-frills engineering and basic accessories, the air-cooled Bonneville T100 has been one of John Bloor’s most significant model releases since he famously purchased the rights to the Triumph brand in 1983.

When it comes to aftermarket parts the popularity of the air-cooled Bonneville T100 has resulted in a gargantuan offering.  As such the classically styled parallel twin has become somewhat of a poster child of the “new wave” custom scene. One place where we didn’t expect to see a custom Bonneville T100 popping up however was in Beijing, China.

This impressive Bonneville T100 cafe racer is the work of Luo Hao and his team at the Chinese custom workshop, Mandrill Garage.

“After the launch of the new water-cooled Triumph Bonneville series, the old models with air-cooled engines feel a bit outdated,” says Luo. “So rather than customising the older model, many people choose to buy the new version.

We feel the old air-cooled engine has a stronger retro feel and is more suitable for modification. Coupled with a relatively cheap price, it is also a good choice for a custom build. The structure of the old model is also simpler and can be modified more concisely.”

A Bonneville T100 cafe racer

To prove his point Luo acquired an air-cooled Bonneville T100 with the intention of building a classic cafe racer – and that’s exactly what Mandrill Garage has achieved.

After the removal of the factory bodywork, Madrill looked for ways to lighten the Bonnevilles physical and visual load. The obvious place to start was the airbox. So along with its side covers the bulky airbox was extracted from the frame and swiftly thrown in the bin. Since the bike was destined to be a single-seater they then removed the passenger footpegs and structure that secures them to the frame. The steel fenders and huge front and rear light assemblies went in the parts bin too, followed by the stock rear sprocket cover, footpegs, handlebars, mirrors, gauge cluster and exhaust. With all that heft gone, it was time to start planning the rebuild.

A Bonneville T100 cafe racer

To set the tone for the project Mandrill designed and built a one-off fuel tank and tail unit. Hand-formed from aluminium the new tank was clearly inspired by the lines of Ducati’s 2006 Paul Smart 1000LE. With geometry adjusted to suit the T100 chassis, the tank looks right at home above the Hinkley parallel twin.

Fitting the alloy wasps tail cowl involved trimming and welding of the subframe and Mandrill’s hard work has resulted in an exceptional fit and finish. Completing the bodywork is a trimmed-down, lightweight front fender and a leather-wrapped seat pad.

In its standard setup, this T100 was good for a modest 64bhp. In keeping with their cafe racer theme Mandrill have made some basic adjustments to turn the parallel twins purr into a growl.

With the airbox out of the way, Mandrill fit the carbs with free-flowing K&N air filters. At the noisy end of the combustion cycle sits a 2-into-1 Zard exhaust system. To then make the most out of the changes they remapped the fuelling. While this has definitely hopped up the Triumph’s dyno numbers the biggest gains on this bike can be attributed to weight saving.

A Bonneville T100 cafe racer

At 205kg the air-cooled Bonneville T100 doesn’t have a power to weight ratio anyone would be raving about. Mandrill had already removed a bunch of weight from the bike with the changes already mentioned, but they knew there were more pounds that could be shed.

Reducing unsprung weight can deliver huge gains in handling and performance so the stock wheels went next. In their place are tubeless CNC aluminium rims and hubs from Kineo. Changing the wheels also presented the opportunity to revise the brake setup so the Bonneville now wears dual front discs wearing Brembo 4 pots.

Next came the suspension and although the front forks look standard, they are anything but. Installed using lightweight LSL CNC alloy triple clamps, the forks feature completely revised internals. The new configuration offers both preload and damping adjustment via adjusters at the top of the stanchions.

In the rear, the changes are more obvious. Mandrill has installed a set of piggyback Ohlins shocks which lift the rear end slightly to level things out.

Good suspension is nothing without reliable rubber. To meet their needs Mandrill went with Chinese made Metzeler Roadtec Z8 Interact tyres.

Mandrill Garage Bonneville T100

The final phase of the build involved selecting which aftermarket parts were going to grace their Bonneville T100 cafe racer. Britain may no longer be a part of the European Union, but Mandrill obviously didn’t get the memo. The bike’s white-faced Chronoclassic gauge and M-Blaze LED turn signals hail from German manufacturer Motogadget. Also coming from Germany are the LSL clip-on handlebars, rear-set footpegs and chain guard. Then from Italy, there’s Brembo levers and a Domino quick action throttle and grips.

Finished in a Paul Smart-esque silver and blue scheme this Bonneville is far from outdated now. Mandrill has achieved their goal of building a classic cafe racer and reminded us all of exactly why the air-cooled Bonneville T100 is such a timeless classic.


A watercooled Bonneville sitting beside an air-cooled T100 cafe racer