Suzuki Rm250 And 370
SUZUKI RM250 AND 370
PREVIEW:
An advance look at the answer to a long list of prayers.
Recently, Suzuki’s public relations department has begun a method of new-motorcycle press introductions that we’ve found to be both tremendously informative and a great deal of fun. Starting with the RM125, they invited the staffs of the major motorcycle magazines out for a day of riding on the new machines. Several bikes were available and they even arranged for team races pitting one magazine staff against another. Unfortunately, not all of the staffs were at full strength because of previous commitments, deadlines, etc., but that didn’t dilute the enjoyment of those who were fortunate enough to participate.
This time, to introduce us to the new RM250 and RM370 Works Replica motocrossers, they rented Carlsbad Raceway for a period of two weeks and invited each staff out individually to do a full day of riding, photography and what have you. Factory mechanics were there to keep nuts, bolts and spokes tight, and to answer any questions we had about the machines. We decided that rather than waiting until we got the machines for a full test, we would give you what information we have at this time. Our impressions are somewhat superficial because only one day in the saddle is nowhere near enough time to do a regular in-depth CYCLE WORLD test. We know that one-day quickie tests are the order of the day at some other publications, so you may no doubt find a so-called “complete” test elsewhere on your newsstand this month. But for us, if these machines are truly Works Replicas, then they’re going to have to prove themselves to us. Our one day on the machines told us that they are like no other Suzukis we’ve ever ridden before. And so far they look real good. Here’s the scoop.
The RMs both share the same chassis.
It is a chrome moly single downtube unit with a chrome moly swinging arm. Footpegs are heavily cleated and springloaded. The rear section of the frame is designed to accept Kayaba gas/oil shocks in a combination forwardmount/cantilevered position. These shocks are very similar to DeCoster’s. >
Up front a pair of long-travel forks absorbs the jolts. The action of the forks was not as universally pleasing as the faultless rear end was, but the units are much better than anything Suzuki has used to date and we’re all very happy about that. The forks feature an offset front axle and nearly-flat-across triple clamps that provide very Maicolike steering characteristics. Also, the offset axle allows for more fork travel, since the tubes can penetrate the sliders to a depth beneath the level of the axle.
Handling on the bumpy Carlsbad G.P. course proved to be outstanding. Of course, we took a couple of spills, but they were on very dry portions of the track where the sudden bursts of power would break the rear wheel into uncontrollable spinning. Obviously, the power characteristics are suited to good tracks that are maintained in proper shape.
The motor is one of the surprises of the year. It features Case-Reed Induction (Suzuki calls it “Power-Reed”), which has been used with success by the Suzuki factory motocrossers, as well as the Honda team and others. The advantage of the new induction system is that it allows for a very wide powerband, yet retains very high top-end horsepower output.
The RM250 sports six transfer ports. The 370 only has four. Dyno tests showed that the 370 can be just as efficient and powerful with only four transfers, so there’s no need to go into the tooling necessary to incorporate the additional two. A down-up-back-acrossand-out exhaust pipe carries away the motor’s spent gases. Mikuni provides the carburetion. Identical (except for jetting) 36mm mixers keep both engines churning.
Suzuki claims 36 hp for the 250 and 42 hp for the 370. We’ll know for sure once we get the bikes on a dyno, but they certainly are bullets on the track. Add to the power the 8.6 in. of fork travel, 8.4 in. of movement at the rear axle, the strong frame-, Dural lower fork sliders, magnesium outer engine cases, non-mud-retaining rims, good grips and footpegs, and a new, 2.1-gal. alloy tank for the pre-mix, and you’ve got one helluva promising package.
The bikes are scheduled to be released soon for magazine testing. As soon as we get one for a month, we’ll find out for sure how good they really are. Until then, all we can honestly do is drool and stare glassy-eyed at the photos.
