Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/125811
g g. Q. N .... '" .n ~ MONTESA Motorcycle 9000 SEPULVEDA BLVD. South of Nordoff in Sepulveda, Calif. (213) 894-9218 From Mexico via Wichita New Bogwheeler: Sale. Service c ~ w Z W ..J U >U OAK HILL WHEEL WORLD CYCLE PARK .... OYBINIGHT , CAMPGROUND * 600 ACRES OF CYCLE TRAILS * REST ROOMS and HOT SHOWERS * 152 CAMPER HOOK·UPS * OVERNIGHT CAMPSITE ..•$3.5Q (Includes all passengers & 1 bike) 50 * DAY RIDERS $1.00 * 25 MI. NO. of SAN BERNARDINO on INTERSTATE -15 (take Oak Hill Rd. Exit) * FOR INFORMATION CALL (714) 244-2422 * OPEN EVERY DAY 4,000 ft. elevation * DAY visiTORS ~he GRM is trim for Observed Trials work, as most riders will probably campaign it. Note right side shift; 26mm Mikuni; pipe tucked way inside frame, which is Grapevine's own design. None Better for Motocross Road or Racing FORIED RACIIiI PI5Ta 5 bl HONDA 750 YAMAHA 360 The best thing that ever happened to a chain. Mfd by. "Blendzall" Corporation 1433-37 First St. Escalon. Calif. 95320 by Norval Hilyard OBSERVED TRIALS, a sPOrt which is on the increase in leaps and bounds (pun intended) is thought by most to be something new, at least to the U.S.A. but friends of Bill Grapevine know otherwise. In 1951, Bill promoted what was probably the first motocross on the American continent and, shortly after that, he began fiddling around with Observed Trials. He promoted a great many Trials and competed in even more. When he rode, he usually rode on a bike of his own design and construction and in so doing he created a demand that exceeded his ability to produce enough of his specialized motorcycles. It was only logical that he should search for an existing factory capable 0" giving him the quantity and the quality that he required in a Trials mount. A lillie more than a year ago, Bill found the' ultra-modern and progressive thinking Moto lslo motorcycle factory nestled high in the beautiful cloud-tipped moun tains of Saltillo, Mexico and an extensive program of research and development began. It wasn't easy for Bill and his tool designer/partner Charles I-lill because there was no one at this factory who had even seen an Observed Trials or a Trials bike. . They did, however, ha1l'e a serious desire to get into the American market so Hill and Grapevine took their combined knowledge. Bill's blueprints for his Trials machine, a hand-built prototype and moved to Mexko where they spent the better part of the year. The result is called the GRM Trialsmaster and some of its specs are as folJows. The frame is made of aircraft quality 4130 steel tube, imported from the United States and put together by Mexican craftsmen. The frame design is Grapevine's own and is somewhat similar to his motocross "Maverick", except of course for the geometry. The new bike uses a single front down tube instead of having a double loop frame. The swing ann is certainly the stoutest to be found on any of the present crop of Trialers and this ruggedness probably reflects the designer's preference for rocky sections. The rear shocks are the very good Boge units manufactured in Guadalajara, Mexico and on the front they use either the Betor or Ceriani for~s~s SUZUKI 400 Street ... Trail ... Dirt ... Motocross - Venolia makes all sizes and bores from 2¥." up. CHEcK US ON DELIVERY! WE CAN'T BE BEAT! SEND $1.00 FOR CATALOG & DECAL. 2160 Cherry Industrial Circle long Beach. Calif. 90805 ·(~13)'636·9329 • 531·846:1 . .... ~ tank and seat sections are fiberglass of a design similar to those found on competitors machines. The powerplant is Moto Islo's own and is only a sligh t1y modified version of the same engine they have been producing for some sixteen years_ Performance is surprising, however, particularly when you consider that the total displacement is only 215cc. Reliability of all Islo motorcycles seems to be fantastic (Definitelyt... Ed.) and evidence of over-engineering can be found everywhere. The crankshaft, for example. rides on four rows of ball bearings and the tr,,?smission can literally withstand pounding with a hammer. The only real modifications to the engine are the addition of an extra flywheel mounted on the crankshaft on the primary drive side and the replacement of the 27mm Bing carburetor with a 26mm Mikuni. The torque and horsepower come from the porting and exhaust system. • Grapevine thinks like Mick Andrews when it comes to wheelbase and location of foot pegs in relation to ~ear axle, etc.. and a tape measure will show that the GRM and the Ossa Plonker have nearly all the same dimensions even though both factories had been into their respective designs for several months before either had a chance to take a peek at the other's model. On the deficit side, the GRM is seventeen pounds heavier than the Ossa MAR but this includes a steel front fender, steel rims, lights, and a trip speedometer. All these can be modified by the purchaser to bring the weight down. The retail price of $795 will allow the owner to do this and still not have as much invested as he would have paid for one of its Spanish competitors. Also of interest to a potential buyer is the price of replacemen t parts which in many cases are around half the cost of"the Spanish bikes. Of interest to would·be dealers will be the availability of parts and bikes, all from a warehouse located in the center of the United States. The distributor is, of course: GRAPEVINE RACING MOTORS INC., 750 East Pawnee Wichita, Kansas 67211 Phone: 316-685-6447 Grapevine should never get caught short of parts due to dock strikes, etc. If worse came to worse he could jump into a truck and drive to the factory for whatever he needed. That's something few distributors can do. Dealers looking for a Trials model to add to their line without having to take_ on a full line of Enduro, motocross, and street models, would do well to drop a line to Grapevine. He's serious about trying to make the world's best Trialer and at the price it's going for you're going to see a lot of them in the hands of folks who simply want a super reliable Trailbike. GRM Inc, is making one of these bikes available to CYCLE NEWS for a test ride soon and the results will be 'passed on to you ~.~ .. ¥