Some motorcycles look fast standing still, but Jeff Duval’s latest creation for Jets Forever winds that up to 100mph, appearing to have been caught somewhere between a Grand Prix paddock and a high-speed run across a Californian dry lake. It is the latest machine to emerge under Jeff’s colourful Montjuich Class banner, an idea drawing together the lightweight road racers of Europe and the stretched, straight-line machinery that flourished on America’s West Coast. This time the starting point could hardly be more appropriate. With a big-bore two-stroke single, impossibly long proportions and one truly magnificent expansion chamber, the Montjuich Class 340 TSS Competition Client looks every bit the machine its name promises.
Bultaco’s connection with the Montjuïc circuit, drop the h, itself runs deep. Founded by Francisco ‘Paco’ Bultó in 1958, the Spanish company went racing almost immediately and became a formidable force across road racing, trials, motocross and enduro. Its TSS production racers represented the sharp end of Bultaco’s circuit efforts: brutally simple, incredibly light motorcycles powered by increasingly potent two-stroke singles.
Jeff had one of the most desirable ingredients for his project, in the form of a 340 TSS competition engine, which was entrusted to French Bultaco specialist Jean-François Vicente. The big single was completely rebuilt using high-spec internals and bespoke machined components, with the emphasis on producing a strong and usable engine, backed by a rebuilt period five-speed transmission.
There was little point in surrounding such an engine with an ordinary chassis, so Jeff turned to John Parry of Cobra Frames to create something entirely bespoke. Parry fabricated the frame from 7/8-inch chromoly tube, adding five inches to the conventional dimensions and setting the steering head at a substantial 37 degrees of rake. The front wheel is pushed well away from the engine, leaving acres of daylight around the polished cases, while the low bars and abbreviated tail keep the visual mass concentrated around the motor. It has the elongated proportions of a straight-line racer without abandoning the traditional twin-shock architecture of the Bultacos that inspired it, and the simplicity of Parry’s tube work ensures the engine remains the centrepiece.
Although the engine might have something to say about that, because running beneath it is one of the most spectacular expansion chambers we’ve seen in a long time. The enormous pipe leaves the front of the cylinder before curling tightly down alongside the polished cases, sweeping beneath the crankcase and extending almost the entire length of the motorcycle.
On a big two-stroke single, the carefully determined lengths, tapers and diameters of an expansion chamber use pressure waves to assist cylinder scavenging and help prevent fresh charge disappearing straight out of the exhaust port, making the pipe integral to how the engine produces its power. Rather than polishing or chroming it, the chamber has been finished in a muted pale grey that shows off every change in section while providing the perfect contrast to the polished aluminium engine beside it.
The suspension and running gear continue the mix of traditional architecture and much more serious modern hardware. A set of adjustable 35mm Ceriani competition forks handles the front, prepared by CR Suspension Kft in Budapest, with the Hungarian specialists also supplying the bespoke twin rear shocks. The chromed alloy wire wheels use stainless spokes, with an unusual 21-inch front and 18-inch rear combination that further exaggerates the stretched chassis and gives the Bultaco much of its distinctive stance. Braking performance comes courtesy of Beringer competition hardware and enormous 11.5-inch K-Tech floating discs, with the drilled rear rotor almost filling the 18-inch wheel.
Despite its competition-heavy specification, the Bultaco wasn’t intended simply to sit around looking pretty or spend its life being pushed between a van and the paddock. Parry worked with Dave Norris of WIRED-IRON to produce a bespoke electrical system and make the machine road legal, while keeping the cockpit about as sparse as possible. Low clip-ons wear polished controls, Beringer hardware and simple brown grips, with a single white-faced electronic speedometer/tachometer tucked behind the tiny smoked screen. The bodywork was developed specifically for the project by Duval, Parry and Vicente, with the long fuel tank following the top line of the chassis into a beautifully minimal seat and sharply upswept tail.
With so much polished aluminium and chrome on display, the paint could easily have tipped the whole thing into excess, but Image Custom Design in Camberley kept things firmly rooted in Bultaco territory. The tank and tail wear deep red over graphite grey with fine yellow detailing inspired by the Bultaco Racing Team, while the frame carries the same graphite finish and a fine yellow line along its lower rails. Hi-Pol handled the extensive metal polishing and SilvaBronz the chrome work, leaving everything from the engine cases to the wheel rims gleaming without overwhelming the mechanical details.
The tank carries the full ‘Montjuich Class 1976 BULTACO 340 TSS Competition Client’ script, and together with the Ceriani forks, spoked wheels and wonderful bodywork, the result has the coherence of a motorcycle conceived as a complete machine rather than assembled from a catalogue of desirable parts.
That is perhaps the greatest success of Jeff’s latest Jets Forever build. Vicente’s 340 TSS engine, Parry’s stretched chromoly chassis, the Ceriani and CR Suspension package, Beringer brakes and that glorious expansion chamber all contribute to the same long, lean and unmistakably two-stroke character.
It is a truly unique interpretation of Bultaco’s competition heritage, but one executed with enough engineering and craftsmanship to make the concept convincing from every angle. Better still, Jeff isn’t keeping this one locked away in the Jets Forever collection: the Montjuich Class Bultaco 340 TSS Competition Client is currently offered for sale through Jets Forever for £29,995, giving somebody else the opportunity to put oil in the tank, a little dust on those tyres and this extraordinary Spanish single back where it belongs, screaming at full glory out on the open road.
[ Jets Forever | Photography by Max Howard ]