Hagon-Triumph Dragster
TYRAG RACING might not be everyone’s “cup-o’-tea” and after trying the real thing we can see why. The 10to 12-second trip up the tarmac, on some occasions, can have all the excitement of a scramble, dirt track and road race rolled into one very short period of time. Although considerable skill is involved, there is no substitute for enough courage to take engine revs to the redline, “pop” the clutch and “light off” the rear tire. What happens from that point is anyone’s guess.
In England, this form of racing is referred to as sprinting and has become very popular. While it is still looked upon as an American sport throughout the world, some major contributions to drag racing have come from England in recent years. It must be admitted that the Avon “slick” has gone a long way to lowering times through the quarter-mile. The slick is a treadless, flat section rear tire and is made from the high hysteresis rubber that has become so popular in road racing. Avon pioneered the development of this unusual compound, which is some times called "dead" rubber, because it has so little life or elasticity, but allows a great deal of traction. In fact, this compound is credited with doing far more to decrease lap times than horsepower. Today, there is more racing than ever before but fewer accidents, as a result of this strange material. When Avon decided to quit building racing tires of any sort, it was a shock to the racing world, but re prieve came later when they announced that production would continue, in limited quantity, of the precious slicks for dragsters.
HAGON-TRIUMPH DRAGSTER
CYCLE WORLD ROAD TEST
One of the foremost exponents of sprinting in the land of tea and crumpets is a small, bespectacled, soft-spoken man of many talents. Alf Hagon is his name. For many years he was unbeatable in grass-track racing, which is a blend of motocross and dirt track. In the early days, Alf worked and raced for Tom Kirby, and perfected the Kirby-Hagon grass bike, which established an entirely new concept in design and is used by virtually everyone in grasstrack racing today.
When Alf retired from grass-track and took up drag racing, he soon started to apply his mechanical skill to the new sport. He found that a derivation of his successful grass-track machine could, with everything else being equal, give better quarter-mile times than existing equipment.
Hagon dragsters have become so popular in England that Alf is now producing arid selling a kit, which is distributed in the U.S. by Kosman Motorcycle Specialties, Daly City, Calif.
The frame is constructed of seamless, mild steel tubing, and all joints are brazed. A large two-inch diameter top tube and a smaller rear down tube carries two quarts of engine oil. The “seat” is brazed to the rear sub frame, and this assembly is bolted to the main frame, very similar to the older rigid and sprung hub model Triumphs. Steering head and front down tubes are rather small compared to more conventional motorcycles. However, on this type of machine there is very little going on in the way of stress loadings in the front end. For one reason, seldom is the full weight of the front end acting on the wheel when the machine is running; and secondly, there is no front brake to impose its loads.
In fact, in drag racing, weight is probably more critical than in any other form of motorcycle competition, as the whole object of the game is to move weight from rest through a given distance.
This accounts, too, for the unusually small front forks on this type machine. Originally, as supplied by Hagon, the machine had Alf s own rubber band fork configuration, but Kosman fitted a pair of Yamaha 60 fork tubes in upper and lower fork crowns of his own manufacture.
We had hoped to try the Hagon theory gnd use a standard 650cc Triumph engine to compare quarter-mile times with a conventional motorcycle, but some tuning had been done on the engine. This consisted of Precision Machining drag cams, 11:1 Triumph pistons and Wert’s aluminum push rods. Otherwise it was a standard 1962 pre-unit construction Triumph engine. Some indication of what can be expected may be gathered from the fact that the machine broke the quarter-mile 650cc gas record on its very first outing. This was at Fremont Drag Strip, where it turned 11.3 seconds and 1 17.95 mph and is recognized as a new national record.
During our testing we were not as fortunate, as magneto trouble had developed since the Fremont runs. To say this made things exciting would be an understatement. It was anyone’s guess as to when the power was going to come on! On occasion, things would happen according to plan in first gear, then momentarily die in second, only to have the power suddenly come back, picking up the front end.
Despite all the guess work in throttle response and mis-firing, even on the best runs, the times we obtained proved the Hagon layout has considerable merit. A very low overall weight makes it an extremely feisty device, requiring much more talent than its roadster counterpart; but then it is designed for a specific purpose, and this is usually what sorts the men from the boys in motorcycle racing machinery. ■
