The Motorbike Archives

The Rickman brothers, Don and Derek, of Surrey, England, must be considered of genius stature because they certainly are the most successful in this game of chassis kits. A chassis kit it everything but the engine. In the case of the Rickman 250 Cross (Modern Cycle, December '71) and the Rickman Micro 125, engines are supplied from an outside source and the machines come complete.

The Rickman Micro is a small displacement moto crosser that can be either powered by a 100cc Hodaka or 125cc Zundapp. The bike we chose to test is the Zundapp powered 125cc class racer, by far the more popular displacement size.

The two chassis are identical except for mounting tabs. Both engines are hung in the frame with four through bolts, they are just placed differently. Two additional struts were added which run from the top of the cases to the upper frame tubes on the 125cc unit. Their purpose is to provide added strength.

All Rickman moto cross frames are made from 531 Reynolds thin wall tubing. They are held together with a low temperature brazing method that is distinguishable by its large fillets. The frames are rigid, lightweight, and nickel plated for easy cleaning.

The larger Rickman chassis features Timken tapered bearings in the steering head to take the heavy loads from the forks. The early run of Micro Metisse frames used cups and balls similar to what is found in the majority of motorcycles running around today. They proved troublesome on the Micro so the later batch have a larger diameter steering head tube and Timken bearings.

Another troublesome part on moto cross bikes, and most others as well, is the swing arm fulcrum bearing. Because of a chronic case of lack of attention grit gets in there and the bushings wear out. The Rickman brothers solved this problem simply by using bonded rubber bushings instead. This bushing also dampened shock transferred to the chassis when the bike lands on its rear wheel.

Chain adjustment by moving the swing arm at the fulcrum is another of Rickman's patented features. The larger machines use a unique set of cam plates to do the job. But this requires about 16 different pieces and some precision machining. The Micros adjust the chain at the fulcrum in a less costly manner. They use the old washer welded to a bolt method like a bicycle.

Because of this unique system the rear wheel can be mounted solidly with an axle through two precision tubes. It's impossible to misalign the wheel in the arm and the unsprung weight is lessened considerably. However, improper adjustment of the swing arm could cock it in the frame and misalign the front and rear wheels if one is not careful.

Movement of the rear arm is controlled by Girling damper units. They're fitted with 75 pound springs which are proper for this machine. Our test bike however, was supplied by Steen's and used Ceriani rear shocks. The new arrangement which makes BSA the importer, distributor of the Rickman bikes may revert them back to Girling shocks.

The front forks are Ceriani medium weight that have close to 6 inches of movement. The hydraulic control is very good, and the balance between the front and rear suspension units is also good. The Micro lofts into the air rear wheel down and settles on the ground with a well controlled thunk.

One of the outstanding features of the Rickman racers is their glass work. (What is not frame or wheels is fiberglass.) The workmanship of the Avon glass is first class with the color impregnated deep into the material. Each piece has a specific function, yet in the case-of the Zundapp Micro, one does not. The left side panel is molded for an upswept exhaust pipe and the 125 uses a down pipe.

The air filter box is cut away to make room for this pipe and uses only one paper element. Past Rickman practices have been to utilize this space for an air filter element on each side of the bike.

The Micro uses self-locking nuts throughout its construction except for the nuts on the swing arm fulcrum and rear axle. If they are not looked after they sometimes disappear at the most embarrassing moment.

There are other parts of the motorcycle that required favorable comment. The nylon throttle is best for lightweight construction and bolts together in such a manner that dirt and grit have little chance of getting into the works. Throttle and clutch levers are those Magura pieces that bend and never break. They are amply shielded from the muck found on good moto cross courses and allow the cables to work freely during a day of racing.

Both wheel hubs found on the Micro Metisse are of the conical type whose purpose is light weight. It's a fact that builders of racing motorcycles constantly keep an eye out for ways to shave off an ounce here and there. The Rickmans are no exception to this rule. The bike uses Dunlop rims which are a shade heavier than the alloy ones. But fill the alloy rims with mud as they do in a race and then compare the weight. The steel rims without the lip are always lighter because there is no place for mud to be trapped.

The brakes at both ends are good. Both brake backing plates form a lip over the conical hubs to aid in keeping crud from entering the brake drum. Although not completely waterproof they come as close as anyone.

In keeping with an effective weight watching program the bike does not come with a cushion in the rear wheel. It's interesting to note Zundapp incorporates a drive cushion in their bikes as a matter of practice. Yet the Rickmans don't seem to have any problems because they have deleted the component, which leads us to believe the gearboxes are pretty stout.

The 5-speed cluster is a little wide for motocross, consequently super fast speed shifts present a problem. The machine changes gears by pulling a shaft through the mainshaft and inserting steel balls into the root of a given gear which otherwise would be spinning freely. The whole mess is a bit complicated, with 20 steel balls being programmed four at a time. Yet the system works smoothly and during the heat of a race shifts are thrown without the aid of the clutch.

The amount one must move his foot to change from one gear to the next is a bit far. The earlier 4-speeds were further and only the prototype 6-speed which I rode at the factory seemed satisfactory. Hopefully, one day we will see the 125cc 6-speeder.

They use pointed ignition by Bosch with a primary coil excited by permanent magnets mounted in a flywheel and a secondary coil attached to the frame under the fuel tank. This system is the simplest and is most reliable. There are no lighting coils although there is a place for them to mount. No sense in having something you won't be needing.

Like the Rickman chassis the Zundapp powerplant is lightweight, efficient and effective. Together they make an ideal racing bike, one that has few peers. We'll let the machine stand on its own impressive record of wins.

Our test crew's only complaint was the use of cross country bars on a moto cross mount. The bars are too high for anything but sitting. The seat, footrests and levers are properly placed so just changing the bars is no big thing. But why do it at all?

In conclusion, if you pay less for an almost racer it's going to cost a whole lot to make it nearly competitive with a genuine Rickman. It will never be competitive. So if you're serious about racing then pay the extra dough and get a serious racer. It's the only way to go. ■