Bultaco 175 & 350 Alpinas
BULTACO 175 & 350 ALPINAS
Cycle World Road Test
Don’t Think Just Enduro Bike. The Lightweight Alpina Concept Is Something New And Unique — Borrowing From Both Enduro And Trials. Call It “The Great American One-Day Machine.”
BULTACO’S Sherpa T, the world reknowned observed trials machine developed by many times world champion Sammy Miller, has won over a large following in the United States and in other countries as well. The Bultaco Matador, on the other hand, was developed by the factory for competition in the famed International Six Days Trial and is a more ruggedly built and heavier machine than the Sherpa T, with long distance enduros being its strong point.
It soon became evident to Bultaco representatives in America that there was a demand for a Sherpa T which would be more suitable for the popular one-day enduro contests in this country. Although the Matador was a machine that could be used for these events, many riders wanted something lighter and more maneuverable for use in these short events as well as a mount for strict pleasure riding.
The Alpina is just such a machine. However, riding one requires a definite readjustment of riding style. Why? Because this ultra lightweight will not slide due to a considerable rear weight bias. And that’s not all. Alpinas really feel strange for the first few miles, unless of course you have been preconditioned to the trials attributes of high pegs and low seat ala Sherpa T.
Actually in its first guise the Alpina held many of the virtues of the Sherpa T: good bottom end power, a narrow profile and a redesigned seat/gas tank combination with greater fuel capacity and a softer padded seat. In its present form, the Alpina is almost 50 lb. lighter than the more fully equipped Matador and is the ideal set up for short enduros and pleasure riding. But the first Alpina, introduced near the end of the 1971 season, was available with only a 250 engine, which was okay if your bag is to ride the 250 class in enduros.
For 1973, Alpinas are available in four of the most popular engine sizes for enduro competition: 125, 175, 250 and 350cc and almost all the cycle parts are the same. The same crankcase assemblies, except for flywheel weights, are used and the big differences to the engines are different size cylinders and pistons.
In order to get a good sampling of the four Alpinas, we requested a 175 and a 350 for test, and although the handling qualities are practically the same, the 350 has much more tractive power than the 175.
In typical Bultaco fashion, the engines feature vertically split crankcase assemblies. On the Alpinas a Femsa flywheel magneto with lighting coils is installed on the left hand end of the crankshaft while additional flywheels are mounted on the right hand (primary drive) end of the shafts. A single row primary chain transmits the crankshaft’s power to a clutch with all steel plates which will take an extrodinary amount of abuse before it gets hot enough to slip or drag.
All four Alpinas have the same internal gearbox ratios which are ideally suited for the machines’ intended usage. The first three gears are more widely spaced than on a Sherpa T as are the top two speeds, so keeping the engines in their powerbands is easy.
All-out performance is not a criterion for these machines so their port timing is on the mild side with good power available from ultra-low rpm right up the scale to peak power speed. The 125 is the buzziest engine in the group, developing its maximum power at 8000 rpm. The 350, on the other hand, puts out its maximum of 21 bhp at 5000 rpm and a whopping 21.5 lb.-ft. of torque at 4500 rpm. Riding the 350 Alpina is more like riding an old 500cc four-stroke Single than a medium displacement two-stroke.
The four Alpinas all use the same frame, which is practically a carbon-copy of the Sherpa T frame. A single toptube runs from the steering head back under the gas tank/seat combination to a point below the seat where it divides and continues rearward, eventually terminating in a loop which serves as an additional seat support and a mounting point for the polished aluminum rear fender.
In an effort to keep the machine’s weight down the lower frame tube attaches to the bottom of the steering head and runs downward to a point in front of the engine. Here it divides into two smaller tubes which continue rearward to a point near the rear of the engine where they slope upward, forming an attachment point for the top rear suspension mounts and join with the top frame tube into the loop section.
Liberal gussetting is provided in the swinging arm pivot point area assuring minimal flex in this critical area which is so important to the handling qualities of a motorcycle.
A perforated steel bash plate is welded between the two lower frame tubes under the engine to protect the crankcase area from rocks and logs while traversing rough country.
The one-piece fiberglass gas tank/seat combination is very similar to the one used on Sherpa T models, but gas capacity is up from 1.3 to 2.2 U.S. gallons and the seat is slightly wider and more thickly padded for comfort. Here you can see the Alpina’s orientation to the enduro or primarily recreational rider, who spends much of his time sitting down. The larger fuel reserve makes the Alpinas capable of running the 40 to 60-mile leg to the typical noon gas check.
Finely finished and detailed, the gas tank/seat combination may be removed by unfastening three screws for access to the ignition high tension coil, electrical connections and the air filter. The filter is located high, just below the seat, which will prohibit the ingress of mud and water during stream crossings. However, the filter material is a plastic gauze which is much too coarse to stop fine dust from entering the engine. One of the popular closely meshed foam elements available today makes a much better filter, and will be fitted shortly.
The Alpina 175, with its practically “square” bore/stroke ratio of 60.9 x 60mm, pulls surprisingly well from low rpm. Quite a bit of de-tuning has been done to this engine, which was originally fitted to the Bultaco TSS 175 road racer and put out more power per cubic inch displacement than any other Bultaco engine.
Flooding the carburetor liberally makes starting the 175 a two or three kick affiar, but the kick starter lever hangs up on the brake pedal near the bottom of its stroke and must be returned to its original position by hand. Once warmed up the engine pulls smoothly and strongly throughout its speed range with no hesitation or “portiness.”
The 350, on the other hand, is more difficult to start because of its high primary compression and the fact that its kickstarter also hangs up on the brake pedal. Once running, the 350 can best be likened to a “tractor” so abundant is the power. Hills which you would think should be climbed in second gear are easily climbed in third and the engine may be lugged down to an idle without stalling.
Besides the power characteristics of the engines, the
constant mesh transmissions deserve the highest praise. Their short throw shift levers provide slick, positive shifts and the upper transmission ratios are so close that clutchless shifting is a breeze. With shafts supported by hefty ball bearings, Bultaco transmissions are among the strongest and most trouble-free.
The Alpina’s riding position is exactly the same with a pleasant (once you get used to it) relationship between the seat, foot pegs and the handlebars. One staff member stated that he would rather have slightly higher handlebars to keep from having to arch his back while standing up, but the rest of the staffers thought the general control layout was just fine, with one exception. The rear brake levers are simply too high in relation to the foot pegs, making it necessary to raise one’s foot to apply the rear brake. And, once it has been applied, great care must be exercised to keep from locking up the rear wheel.
The front brake, on the other hand, provides good stopping with a moderate amount of lever pressure. The front wheel hubs are very light in that they have a steel film applied by an electrolytic process to the inside of the drum rather than a heavier cast-in liner.
Every attempt to save weight has been made on the Alpinas. Akront aluminum alloy wheel rims are fitted to the small wheel hubs, light alloy handlebar levers are used and the marginal lighting equipment, which will be removed by most owners, is also very light. An aluminum alloy rear chain guard is fitted and a spring-loaded rear chain tensioner helps keeping the chain from being knocked off the sprockets by branches.
Another feature we particularly liked was the aluminum alloy front fender which is mounted beneath the lower fork triple clamp with a steel strap which permits it to flex, dislodging mud which may build up under the fender.
Bultaco has seen fit to use the standard silencer which is a rectangular affair with a perforated tube running through a fiberglass packing. The outlet end is significantly smaller than the inlet end, but the sound emitted is somewhat louder than we like. Additional supplementary mufflers are supplied with each machine which cuts the noise level down considerably. We rode the bikes with the additional mufflers installed and didn’t notice any reduction in performance.
One area in which Bultaco could improve silencing is at the intake side. At moderate to large throttle openings a distracting roar comes from the air cleaner under the seat. It certainly isn’t loud, but it is unpleasant in tone.
Handling characteristics of the Alpinas are first rate. The front forks are manufactured to Bultaco specifications by Betor and with an improved air valve in the top nut, movement of the legs up and down over the bumps is smooth and progressive. Almost 6.5 in. of travel are offered by the front forks and the five-way adjustable springs on the rear suspension units will compensate for the weight of practically any rider. These rear suspension units allow the rear wheel to follow undulations of the ground and provide nearly 4 in. of travel.
The pride in ownership of a motorcycle, be it for the street or for strictly off-road use, is very important to most owners. Detailing on the new Alpinas is better than that we’ve seen on previous Bultacos and is almost as good as on any machine. Aluminum parts are highly polished or smoothly painted, the fiberglass work is as smooth as any we’ve seen and the appearance of aircraft-type self-locking nuts add an air of professionalism to these competition-bred machines.
Of course, we predict that as many of the Alpinas sold in the United States will be used strictly for pleasure riding as for serious enduro competition. But for whichever purpose, Alpinas are very desirable machines.
BULTACO ALPINAS
175
$921
350
$1127
