The Borile B500CR is an exceptionally neat-looking machine. The frame’s exaggerated curves are inspired part by function – to clear the round airbox covers at each side – and partly, says designer, motorcycle dealer and part time artist Umberto Borile, by " hills and beautiful women " .
The CR (that bit stands for Café Racer) is descended from a prototype Borile unveiled at the Milan Show almost four years ago. It’s now finally ready for production using a new motor, much of which he designed himself.
Borile’s engine is based on the GM speedway unit, designed by his friend, the Italian racer/engineer Giuseppe Marzotto. The GM won a string of world championships in the 1990s. Now burning petrol rather than methanol, the 500cc air-cooled sohc four-valve motor is much modified, with extra cylinder finning, a softer camshaft and reduced compression ratio. It puts out 45bhp at 7200rpm, compared to the race motor’s 70bhp.
Borile designed and built the exhaust system, plus the distinctive round airbox arrangement that feeds the 36mm Mikuni carburettor. He also designed a five-speed gearbox (speedway bikes don’t use one), revamped the lubrication system and added a kickstart.
He takes great pride in welding and bending the aluminium tubes to produce his frames. The swingarm, which operates a vertically mounted Bitubo shock, is also made from tubular aluminium. Fitted with Ceriani 41mm upside-down forks, 17-inch wire-spoked wheels and a single disc brake at each end, the B500CR has a claimed dry weight of just 104kgs.
Borile has two versions of the single when I pay my visit: the silver original model, which is a non-runner because some bits are away being copied for the production machine; and a black-tanked prototype that Umberto is riding around to fine-tune a few things before starting work on his first batch of production bikes.
I have to hastily relearn the ritual of easing the engine to compression with the kick-starter, pulling in the decompressor lever and prodding it over a bit more… then leaping with all my might. The CR normally needs several goes before it burst into life with an aggressive – but oh-so impressive – thrapping sound from its sawn-off pipe.
With its 45bhp output the little single is never going to be the world’s fastest bike , but its lack of weight ensures that even this modest output is enough for plenty of fun. Its Mikuni carb isn’t perfectly set up, and gives a slightly spluttery response from low revs. But that soon clears and the little bike leaps forward with enough force to make the narrow Tommaselli bars tug at my shoulder-s.
The bike works best well below its top speed of about 110mph. It cruises reasonably between 60 and 70mph, and is smoother than I expected given the lack of balancer shaft.
In bends the firm and well-damped front end gives heaps of feedback, and steering is light and effortless yet also stable, thanks to the not-particularly-steep 26.5° fork angle. The front brake set-up of four-pot Brembo caliper, biting an enormous 350mm disc, combined with the CR’s lack of weight means the bike can be stopped on a 100 lire piece with a light squeeze of the handlebar lever.
The prototype’s one handling flaw is that its Bitubo rear shock is far too soft for my 14-stone butt. If the bike is to reveal its full potential to heavier riders it needs a stiffer spring, which Borile is planning to offer.
Inevitably, a hand-built bike like this is not cheap, but the B500CR’s price of 21 million lire (around £7000) is reasonable considering how much inspiration and perspiration have gone into producing it. Borile is taking orders for a run of 50 kickstart-only Café Racers for delivery in December, followed by some electric-start bikes.
More on this in MCN, published August 29, 2001