Cycle News - Archive Issues - 1970's

; w ,; • • ~ t 00 !:' 0') ~ 0') ~ e-, ..... ::3 ~ or works , on Team Honda , The two different bikes are nearly identical and many of the chassis and engine parts are interchangeable, Riders Pomeroy and Ellis have works RCs for the Nationals, while Marty Tripes used the production CR in the Supercross Series and then showed up at the 250cc Nationals with a production engine in a works chassis, Magnesium or aluminum. cased engines use chrome or steel sleeved cylinders with reed induction, depending upon the rider's seniority with the team. The Hondas dominate the starts. so they win the horsepower race. The RCs are a little quicker than the CRs, though. The bikes come delivered from Japan with Showa reservoir gas/oil shocks and Showa front forks with spring-only suspension. Nearly all the team riders favor changing to Fox AirShox for the rear suspension. while up front some have even installed Simons air/spring forks. That's quite a departure from Team Honda of a little over a year ago when they wouldn't allow any modifi cations to the factory bikes. Suspension travel is usually 12 inches at each end , and weight can be as low as the FIM 194 pound minimum if all works parts and lightweight tires are used . Husqvarna 250 CR 1978/79 Chuck Sun's factory Husky is basically a stocker with a prototype frame that is already in production and will be on the new 1979 models this fall. The frame has minor geometry changes and a new swingarm that is wider at the frame pivot. Mechanic Eric Crippa has increased the stock Husqvama fork travel by one inch with the addition of longer fork tubes , damper rods and springs to achieve 10.5 inches of travel. At the rear suspension travel is increased to a total of 11.5-12 inches with Ohlins reservoir gas/oil shocks, the same length as the Husky OR model shocks , working in conjunction with the new swingarm. . The ported stock engine uses an experimental new expansion chamber, and a new side access airbox that will be on the new bikes this fall. Carburetor is a 36mm Mikuni . Husky's reputation for reliability is supported by the fact that Chuck is using the same cylinder that Kent Howerton ran on his bikes in the Supercross Series and 250cc Nationals last year. Complete bike weight is 227 pounds, which isn't out of the ballpark when compared to the Japanese production bikes, but it could be made lighter with a new down-sized engine that's expected in another year. Suzuki RH 25Q-78-X Kent Howerton's new Suzuki gets a redesigned smaller and lighter engine just like its big brother the RN · 400 which was unveiled in last fall's TransAMA Series. The clutch actuator mechanism is now relocated to the left side of the magnesium sand cast engine. Suzuki's case induction Power Reed system takes ca~e of cylinder induction. with the cylinder itself using a rather heavy steel liner as compared to the other works bikes. Only a five-speed gearbox is needed . because of the broad powerband the long stroke RHmill produces. Engine specs are similar to an RM 250C, but with the intake and exhaust timing specs less radical. So far. Suzuki has the most suspensiontravel with 13.5 inches out back provided by Kayaba gas/oil reservoir shocks and up front 12.0 inches with Kayaba air/spring prototype forks. Gaston Rahier has been seen in Europe with a test bike using 15.0 inches of suspension at each end. Liberal use is made of lightweight materials such as titanium in most of the fillings and such items as the footpegs . Magnesium is even used in the upper triple clamps for the forks, with the lower triple clamp and steer stem milled from aluminum. The complete bike isn't as light as one might expect for all this exotica . tipping the scales at approximately 215 pounds. Carabela 250 MX-78 Billy Grossi is riding the only new entry on the American MX scene this season, the Carabela 250cc motocrosser. So far the bike has been plagued by engine reliability problems, but while it's running, it seems to be competitive with the ."Bear" at the controls. Numerous accessory parts like Simons forks. Fox Airshox and a Cross Up bent-style aluminum swingarm help to improve the bike. Engine is a five-speed unit. rumored to be using a Yamaha reed valved top end. Reliability problems with Mexican-built bikes like the Carabela and the jones-Islo are mainly due to the unavailability of high quality metals and the equipment needed for accurate machine work sou th of the border. Beca use of these handicaps , Carabela deserves much credit for such an impressive first efforl. • 19

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