Borile B450 Scrambler

As with other Borile models, the B450 Scrambler relates to a nostalgic bike loved worldwide: the Ducati Scrambler from the 1960s and 1970s, conceived and styled by the then-U.S. Ducati importer, Mike Berliner. He was inspired by a bike that one of his dealers had created from a Ducati 250 Diana, a motorcycle that successfully raced in 250cc dirt-track. The Ducati Scrambler was an instant success, and its lean, daring and “very American” style left a lasting impression. It became a collectible, and many Scramblers are kept in perfect riding condition, even better than when they left the Ducati assembly line, which wasn’t known for its quality control back then.

The old “bevel-gear” sohc Ducati Single, in 250, 350 and 450cc displacements, was a lovely engine, in Fabio Taglioni’s best engine-design tradition, but it was plagued by an intolerable percentage of crankshaft failures, to the point that it killed the whole line of models it powered. And with them it also killed the very image of Ducati, which remained at its lowest level for years. Still, the Ducati Scrambler survived as a legend, an icon from the time when motorcycling had returned to being highly fashionable.

Now that he treads on more solid financial ground, Borile thought he would recreate the Scrambler, since Ducati did not seem interested. He took the vertical cylinder from a sohc 1100cc Ducati, designed a very compact and neat crankcase in which he shoehorned a cassette-type six-speed gearbox, a balance shaft and an electric starter. He also developed his own crankshaft with a 60mm stroke, arriving at a displacement of 452cc by using the standard 98mm bore. Borile could not afford the cost of a new die for a forged, solid crankshaft, so he resorted to a three-piece, press-together crankshaft featuring a 35mm crank journal, the same diameter as the main journals, that turns on the traditional “angular contact” ball bearings that Ducati adopted back in 1972.

The connecting rod is Borile’s own design, turning on plain bearings and featuring a 135mm center-to-center measurement, thus much taller than the 124mm Ducati rod. The extra length compensates for the shorter stroke, but in the process, it makes the piston lot happier and, most important, its generous 2.25:1 ratio to the stroke drastically reduces the secondary imbalance and related vibrations. Since a balance shaft takes care of the primary imbalance, the engine is perfectly smooth. The vertical cylinder of the sohc V-Twin retains its original layout, with a front-facing throttle body and rear-facing exhaust. The airbox is wrapped in a false tank accurately styled like the original Ducati Scrambler’s and featuring the same bright yellow/chrome paint and graphics.

In Borile’s traditional fashion, the gas tank is located under the seat. The engine breathes through a proprietary 40.5mm throttle body, replacing the 45mm Ducati unit to further enhance flexibility at low rpm. The 12:1 compression ratio is surprisingly high, which contributes to claimed peak power of 43 hp at 6500 rpm and 34.7 ft.-lb. of peak torque at 6000 rpm. Given its dry weight of only 287 lb., the B450 Scrambler should be pleasantly spirited, and it has a claimed top speed of 100 mph.

Borile designed a frame partly inspired by the old Ducati Scrambler’s. It features an upper backbone with a large-diameter single downtube in front. At the rear, there’s a classic double-downtube structure that’s triangulated. Where the new frame diverts from the original is in the front downtube, which does not bolt to the engine to make it a stressed member of the chassis. Rather, it’s bolted to a double cradle consisting of two thick aluminum plates that also support the engine. As on the V-Twin, the swingarm pivot goes through the crankcase.

With its 53.9-in. wheelbase, a 19-in. front wheel and 18-in. rear (both shod with cross-ply semi-knobby tires), the B450 Scrambler is a compact bike. The fork has 41mm tubes and an offset axle; the rear features twin, fully adjustable shocks offering 5.5 in. of travel. Single brake discs front (260mm) and rear (220mm) ensure plenty of stopping power.