The Bikes

Designed and Built in Great Britain

Rex and Ruby share the same platform and underpinnings so the mechanical specification is identical – the main differences being handlebars and bodywork. These parts are interchangeable so if you wanted, you could turn your Rex into a Ruby or vice versa…


Rex has a relaxed riding position, with wider, more upright handlebars and mirrors to suit. The exact rise and width of the handlebars can be tailored to suit the rider. Rex’s seat and tail-section is subtly different from Ruby’s with a nod to flat-tracker styling. Rex is shown here in ‘Nero Profundo’, a bottomless, glossy ‘piano’ black. 


Ruby has a sporty riding position, using traditional clip-on handlebars which can be positioned to suit the rider’s preference. Ruby’s seat and tail-section is subtly different from Rex’s with an obvious nod to the cafe-racer genre. Ruby is shown here in ‘Flame Red’, chosen to complement her curves.


Our engine is built by SWM in Italy and is used in their ‘Superdual’ adventure motorbike. It’s a direct descendent of the engine which Project Engineer Dr. Ampelio Macchi originally penned for Husqvarna.

Here’s some of the details ;

  • Single cylinder, 4-stroke, liquid-cooled
  • 4-valve head, chain-driven, double overhead camshaft
  • Compression ratio is 12.4 : 1
  • Bore is 3.94 inches or 100mm
  • Stroke is 3.01 inches or 76.4mm
  • Displacement is 36.6 cu. in. or 600cc
  • Electric start
  • Fuel is fed-in using Mikuni 45mm electronic fuel-injection
  • It’s got a 1.8 litre wet sump with cartridge-style oil filter
  • The clutch is hydraulic, with an oil bath and multiple discs
  • Transmission is via a constant mesh, 6-speed gearbox.
  • It produces 52 bhp in standard trim (at the crank)

The Frame and Swing-arm

The steel tubular backbone and cradle frame, with a triangulated swing-arm are unique to Mac, designed and engineered by our grey-haired engineers.

Factory-finishing is done with a 3-part, automotive-standard coating in grey (it’s one of the current ‘Landrover’ colours)


We’ve grown-up admiring the coachbuilder’s art, using an English Wheel to fashion proportion, cohesion and fit from inert sheets of aluminium alloy.

Acerbis in Italy have interpreted our design/intent using their industry leading manufacturing process. The tank holds 12 litres / 2.5 gallons and the ‘idiot light’ comes on when you’re getting low.


Mudguards, seat-base and hump are all made from ABS plastic, here in Blighty.

P.S. we nicked the idea of the fading crease along the mudguards from the body-panels on an Alfa 156.


Taiwan dominates the world’s production of precision stanchion tubes so we’re benefitting from a pair of Fastace’s sensibly-priced and well-made 47mm upside down front forks, with both compression and rebound adjustment as standard-issue. Travel measures 130mm.

Closer to home, our rear shock-absorber comes from the chaps at Nitron, just down the road from us in Witney, Oxfordshire. We fit a Nitron R1 as standard which has umpteen clicks of rebound and compression adjustment, a 40mm piston, a 14mm piston rod and adjustable preload.


Built on a 17” x 3.50” SM Pro Platinum polished silver rim with a British-made front hub, 9 gauge stainless steel spokes and nickel-plated brass nipples.

Tyre choices include;
120/70R17 58H Michelin Street Radial or 120/70ZR17 58W Avon 3D Ultra Sport

Built on a 17” x 4.25” SM Pro Platinum polished silver rim with a British-made cush-drive hub, 8 gauge stainless steel spokes and nickel-plated brass nipples.

Tyre choices include;
150/60R17 66H Michelin Street Radial or 150/60ZR17 66W Avon 3D Ultra Sport


The front ‘anchor’ uses a Brembo radial caliper, gripping a 320mm floating disc, fed by a Brembo master cylinder.

The rear ‘anchor’ also uses a Brembo caliper, gripping a 240mm disc, again fed by a Brembo master cylinder.


The exhaust is made in Italy, by QD to our exact design. The entire system is fabricated from stainless steel and designed to meet current noise and emission legislation, whilst retaining the distinctive ‘soundtrack’ of a big single.


The seat height is: 760mm
The wheelbase is: 1,430mm
Top speed is around 100mph, depending on the size and shape of the jockey, the forces of Mother Nature, the incline of the hill and the tow from the vehicle in front.

By using this website you agree to accept our Privacy Policy and Terms & Conditions