Custom cafe racers are mostly a labour of love. No-one's going to get back the sweated hours perfecting a look, an engine upgrade or meticulously manufacturing that final essential part. The ultimate results, as our two stellar contenders show, are what it's all about. Starting points are prosaic enough: Honda's ugly duckling CX500 and BMW's workhorse R100. These unlikely transformations - supercharger on a motorbike, anyone? - have produced two radically different machines, each highly desirable in their own unique way. Which of these custom cafe racers will be your choice?

Honda CX500 cafe racer | Built by Harry Blaise Fryer with Jackson Motorcycles, London

Designed for the chic city streets, this is a Honda CX500 that shrugs off the model's ugly duckling tag. Creator Harry Blaise Fryer doesn't mince words. "The CX500 is a notoriously ugly bike," he says, noting that the finished custom not only had to overcome this unwanted heritage but  "had to look like it was designed for speed but retain its certain classic qualities."

The build at Jackson Motorcycles started with not one but two CX500s, bought from the same owner. The best was selected, and promptly stripped right down. Gone is the rear subframe, replaced by a short, sharp bespoke subframe very much in the classic cafe racer style. Rear suspension is now monoshock. Front forks are from a Suzuki GSX-R600 with an added conversion kit by Cognito Moto. Clip on handlebars - finished with Renthal grips and grip-end Rizoma indicators - further transform the front end.

The CX500's clumsy fuel tank is replaced by an elegant unit from a Benelli Mojave, finished in a blue that will be familiar to rally fans, taken as it is from Subaru. "This new shape," says Harry Blaise Fryer of the Benelli tank, "really compliments the 45 degree V-twin headers, that sit perfectly astride the knee indents.” A shortened exhaust adds throaty noise and complements the slashed-back look, while a bespoke saddle hides up-to-the-minute electronics. The end result is perfect for your Mayfair home.

BMW R100 supercharged | Built by Ben Norton, Oxfordshire

Fast doesn't quite begin to describe it. Creator Ben Norton's day job is as a Formula One engineer so he knows not only all about speed but where and how to out-source everything from paintwork and upholstery to bespoke machining, using the latest computer technology. The result, we think you'll agree, is pretty breathtaking, even standing still.

This is one brute of a machine. To cut to the chase: the supercharger is an Eaton M24, chosen not just for pace but for the the sound and the low end torque, which rivals just about anything on the road. The engine is extensively modified, using bespoke parts made by Norton's contacts, notably Aximech of Sweden. A methanol injection system - but of course - helps to keep the otherwise over-worked engine cool. Two new tanks - for petrol and for ethanol - now nestle beneath a carbon fibre fairing that mimics the original BMW tank. Stealth genius.

The new seat, in Alcantara, features charcoal and bronze stitching and was crafted by Scottish expert Tom Hurley. Final paintwork finish, by Pro-Kustom, is in matte black, complemented by bronze detailing to the engine, front forks - from a BMW S1000RR - and the bespoke exhaust with its TYGA MotoGP-style silencer. Rear suspension features adjustable ride height and a shock absorber from a Ducati Panigale. The finished machine is way more than the sum of all of these high-end parts, with the BMW's stop-the-traffic looks matched only by its extraordinary acceleration. Sublime.

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