AJS Stormer 250cc. 1972.


42. AJS Stormer 250cc / 1972


Moto cross. Say those two words and you think immediately of brands like, Husqvarna, Maico, CZ . . . uuh, hmmm. In the United States, those three names dominate the action.

 When you talk moto cross, you talk Husky, Maico and CZ.

Well, the Big Three have been placed square in the crosshairs of a brand that’s been around about as long as the sport ….. AJS.

The latest version of the AJS 250cc Stormer, is as good, as any of the top-rated threesome we’ve already mentioned and now has some extras, that the Norton Villiers people hope will have serious racers buying British instead of German, Swedish or Czechoslvakian. Like any fine piece of specialised machinery, this machine is functionally stark, a lean no frills racing machine with one aim in life, to win in the hands of its rider.

Although the latest version looks almost exactly like the first batch of bikes imported in 1969, those looks are deceiving.

Web 218

AJS Stormer 250cc Advertising / 1972

AJS engineers, attuned to the suggestions of racers, both here and abroad, have incorporated a whole bushelful of technical improvements which make the hungry looking Ajay a faster, better handling and more reliable mount than previous issues. While early versions certainly weren’t down on power, all the power in the world is useless unless it can be effectively used in a variety of conditions.

Web 220 
Web 219

AJS Stormer 250cc & 410cc Advertising / 1972

The first Ajays were, in a word, peaky, developing a great rush of power when the revs started to climb. The latest version, however, has benefitted immensely from important changes to both port configuration and timing. The result is a very tractable mount, which pulls surprisingly well in critical situations, like out of corners and on starts.

The AJS engine with its slight modifications has proven to be quite tough under race conditions. A new 10-fin barrel has also been fitted to assure an adequate degree of cooling. The all alloy unit has a spun cast iron liner to accommodate a bore of 68mm and a stroke of 68mm. Square you might say.

Web 221

The compression ratio is a hefty 11-1, which means a listed 25 horsepower at 7000 rpm with 22 lbs./ft of torque to take care of those steep hills. The four-speed gearbox, the same as in the earlier model, uses improved materials in key areas, particularly the gearshift selectors that were prone to breakage under exceptionally hard use. The all metal, wet, diaphragm spring-type clutch delivers the go to the rear sprocket which has been improved by using full length bolts that provide an extra margin of security.

Unifying this exciting power package is one of the more unorthodox frames going, a spindly looking wisp of a unit whose strength belies its fragile looks. In truth, it is as strong as an ox.

The main feature is a robust tapered top tube, roughly an oval in shape. Running from the steering head to a point under the seat, the diameter tube provides the main support for the rest of the frame which is fashioned from rather small tubing in a double loop cradle design, two tubes handling the engine and two jutting up at an angle from the swinging arm pivot to form the classic triangulated pattern.

The whole package, then, is tough, flex free and capable of withstanding just about anything short of an endo into a cement plant at 90 mph.

One of the striking things about the Stormer visually is the amount of space around the engine. Even with the expansion chamber looping up and through, there’s plenty of empty space, which makes plug changes and other fieldwork a joy.

One of the main reasons there’s so much space is the fact that the engine sits so low in the frame, an important key to why the AJS is such a good handler. The centre of gravity is really down there and the bike sticks like glue when pitched into muddy turns and the like.

Perched almost procariously on the long main down tube is a handsome fibreglass tank, impregnated with bright orange paint. Another fibreglass unit, the seat base that supports the very comfortable seat, has been thickened to prevent breakage, a problem on the earlier model.

Web 222

The steel rims have been replaced with lighter Akront alloys, front and rear. Fork damping has been eased; previous models gave a particularly severe ride, steady to be sure, but the forks were somewhat stiff. The front fender mount is fabricated from spring steel, it now gives where the old one merely bent or fractured.

The clutch-operating pin is now made of a tougher, more durable material. An effective Filtron washable foam air filter replaces the old paper one.

Each engine is dyno-tested for 20min at the factory before going into a Stormer frame. These are but a few of the more significant changes, again, like the groove on the mainshaft holding the cluch circlip being deeper to improve clutch reliability, all improving this already fine machine.

Of course, the most noticeable improvement has been in the engine department.

The changes in port shape and timing have made the Stormer even more enjoyable to ride. However, you must approach the motorcycle on its terms. It is a genuine racer, not a dual-purpose street scrambler. The starting ritual is very, very simple.

Tickle the Amal concentric carburettor until it cries, fold up the footpeg and jab down on the right side kickstart, the engine comes to life easily and, even better, stays around to idle, something out and out racers don’t usually do well.

Web 223

Pull in the clutch, which has a particularly light action at the lever, and snick the lever upward with a toe into first. The pattern takes a little getting used to, one up, and three down. More than once or twice we overshot corners or turned hairs white, by upshifting when we should have been downshifting, or vice versa.

The gearbox operates smoothly with only a trace of jerk, as the power is delivered to the rear sprocket. The motocross models sport a closs ratio gearset which keeps the engine humming between shifts, Desert Racers can chose to have a wide ratio setup.

Riding the Stormer, you feel in control, the bike isn’t such a handful that you feel like an untrained monkey strapped to a machine with a will of its own. The quick throttle allows instant acceleration and this can get the neophyte in trouble with wheelies and other antics.

However, if front wheel aviating is your bag, the AJS is up to it with balance about right to carry the front for any distance. While the Stormer was bred for moto cross, a quick excursion on a semi-smooth TT Scrambles course demonstrated that the Ajay can slide and leap with the best of them, and you can chose to have an up or down pipe to suit your needs.

The latest 250cc AJS Stormer compares favourably with the other big three already mentioned, it has the power, handling and reliability of a thoroughbred mount. It’s provided with a spares kit and other accessories, and words of praise, it finally comes down to, will it win?

Well the bike is fully capable of running with and beating its global rivals, the rest is up to you.

 Web 224


AJS STORMER 250CC   25BHP    1969 – 1973 – Y4

AJS STORMER 370CC   30BHP    1970 – 1971 – Y5

AJS STORMER 410CC   37BHP    1971 – 1973 – 410

Return to Contents.