Cycle News - Archive Issues - 1970's

of propess GRAND OPENING of our new Self Service Accessory Department. Hundreds of items on display at competitive prices, with trained motorcycle p,eople to help make yOU! selection. One of the most historic and successful road bikes ever built was the 1936 Over $50,000.00 inventory of accessories in nock now; one stop Christmas shopping for the matoreyele family. 350 and 500c:c Velocette KTT works bike. It featured swingllrm suspension, a very modem approech .,d enjoyed a reputltion for superb handling at speed. exhaust port, and less tendency to foul spark plugs. DKW applied this theory to their 1935 250cc grand prix bike with great success, winning the European Championship from then until the war halted all racing. These "Deeks" also had a- piston compressor and water cooling, along with a reed valve. In I 936 the reed valve was dropped in favor of a rotary valve, and then in 1939 the piston pump was dropped in favor of a rotary supercharger. After the war supercharging was not allowed, so once again DKW had to develop a two-stroke racer that could win. In the middle 1950's their 350cc "three" reached 145 MPH, with this model having the first crude expansion-box exhaust system. Walter Kaaden at the MZ works then took over and staggered the world with the speed he obtained from his 125 and 250cc two-strokes with rotary valves and highly developed expansion-box exhausts. Then came the Japanese, wl\o have perfected such things as pressure oiling to the lower end, more cylinders, water cooling, and disc valves on even their roadsters. More research has gone into the Kaaden idea of adding extra transfer ports, which has helped lubricate the wrist pin bearing as weU as add even more power to the engine. Transmitting the power is another area where great progress has occurred. In the early days this was accomplished with a single speed belt. Next came a clutch, but it was left to the American Indian to really get the show on the road. Indian won the Isle of Man in 19II with a two-speed countershaft gearbox with all-chain <4ive, and this idea soon swept the whole industry. In the 1920's the rage was a three-speed box, and then came Velocette's famous positive-stop foot shift on their works racers in 1928 that did away with the slow and clumsy hand shift. In 1930 Rudge swept the Isle of Man with their four·speed racers, and then in the early 1950's Moto Guzzi showed the world what a five·speed 250cc single could do. During the 1960's the racers began appearing with eight to 12-speed boxes, with much of this rubbing off on new roadsters with boxes up to six and even eigh t-speeds. Another area where progress was painfuUy slow was in suspension systems. Up until the middle 1930's the rigid frame and girder fron t fork were accepted practice, which combined for a bone-jarring ride. Then came the 1935 Senior IT win by Guzzi with their wide.angle twin which had a pivoted-fork rear suspension, which motivated everyone into designing some type of rear suspension. The most significant was the swinging-arm frame on the 1936 Velocette works racers and then the 1939 replica 350cc KTT. BMW worked on the front end with success, with their 1936 racers appearing with a modem telescopic front fork. Getting stopped in time was also an area that road racers have benefited roadsters, with the in ternal expanding brake doing away with the caliper brakes in the early 1920's. Brakes got much larger and air scooped in the late 1930's, and then in 1948 Norton came out with twin leading shoe front brakes on their racers, foUowed by BMW using the idea a few years Ia ter on _their roadsters. Despite these significant inventions that were proven on racing bikes, there are still those who say that racing does not improve the breed. History proves differently. In the next chapter we will present many more significant but less obvious improvements to motorcycle design through the years, once again showing how racing has had a mighty hand in how the motorbike has evolved since the tum of this century. # Authorized Dealer for Bell-McHaI-Shoei-T C Racer Helmets Bill Walters-GP:"'Dynamite & Luja MX Pants Koni-Arnaco-Mavrick-Betor Shocks Walker-Norstar-Webco-GP-Viking Boots A complete selection of kids riding gear. leather pants. boot. gloves, jerseys, knee peds and many more items now in stock. Free drawing for hundreds of dollars worth of merchandise. Pick your ticket and match with the winning numbers, with any purchase. I I I - - - - - - - - VALUABLE COUPON - - - - - - - - 10% discount on any item in our new Self Service Accessory Department. Valid December 1 to January 1, 1974 I ------------------------Christmas hours-start Dec. 10th Daily: 9:30 a.m. to 9:00 p.m. Sundays: 10:00 to 5:00 p.m. CIa-! December 24th at 1 :00 p.m. I I T&OYAMAHA 24020 NARBONNE AVE., LOMITA, CA 90717 (213) 534-2311 .., Fabulous 4-Stroke Probably the first successful hi~1J8rforrnance twCHtrokes were the 1939 DKW 250 and 350 racers. They had a rotary valve, rotary supercharger, water cooling and Dr. Schnurle's loop scavenging: Rear suspension was plunger type. SHORT AVE is 45 HP and 209 Ibs BIG SIX is 50 HP and 220 Ibs Awilable now at 714-477 -2708 Ring Cycle WMm• • HOIIDA Motorcycle Trailers Bell Helmets Full Bore Products 14324 E. Whnie< Blvd. (213) 69ll.Q065 Complete stock of parts and accessories for street and dirt. 500 W. 16th St. National CitY. Calif. 92050 (714) 894-2623 , &wT0il. MOM-11K, a TYItAIII Slltes - service - P.wts - AccesSOries . 0& R Cycles 1181 Westminster Ave. Westminster. Calif. 92683 57

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