AND MOTORCYCLES FOR 1957 Reprinted from 27 September 1956 Associated Motor Cycles Limited Plumstead Road London, S. E.1 8 Telephonewww.ajs-matchless.info: Woolwich 1223 Telegrams: MATCHLESS-LONDON-TELEX. TELEX No. 2-2617 2 THE MOTOR CYCLE, 27 SEPTEMBER 1956 ROADSTERS, COMPETITION MOUNTS, RACERS, FOR NEXT YEAR : MEASURES TO ENSURE OIL TIGHTNESS : ENGINE PER- FORMANCE INCREASED : LATEST GEAR BOX AND CLUTCH SPECI- FIED : NO PRICE INCREASES A.J.S. and Matchless Modifications OURISTS, racing men, trials riders Above: The 498 c.c. A.J.S. and scramblers can all find models model 20 fitted with chromium- to whet the appetite in the A.J.S. plated tank panels Tand Matchless ranges which are, of course, basically similar. All models have pivoted-fork rear springing and telescopic front forks. The roadsters—comprising Right: Largest - capacity singles of 347 and 498 c.c. and parallel Matchless is the 592 c.c. model twins of 498 and 592 c.c.—are renowned G11 for their comfort, high-quality finish and mechanical quietness. A unique, three- tank decoration. For the first time since those for the three clutch springs is ob- bearing crankshaft layout is a feature of rear springing was introduced in 1949 pro- tained by removal of a dome from the the twins which have an enviable reputa- prietary shock absorbers are used in place primary chaincase. tion for robust construction and tireless of the A.M.C.-manufactured units. In General liveliness of A.J.S. and Match- performance. addition to the foregoing changes there less roadsters has never been in doubt. The wide popularity with amateur are several minor modifications aimed But it is the makers' experience that many sportsmen of the trials and scrambles chiefly at cleaning up appearance and buyers attach considerable—and, per- models furnishes eloquent testimony of eliminating oil leakage. haps, undue—importance to speed and their suitability for competition riding off A redesigned frame for the trials model acceleration. Hence the quest for more the beaten track. Although the scrambler is of real significance, since it results in engine power which has led to the adop- is available both as a three-fifty and a a 3in increase in ground clearance. Cross- tion of a new inlet cam for the singles five-hundred, the trials model is marketed country racing men will be delighted to and modified inlet and exhaust cams on only with a 347 c.c. engine; all the power learn that the power output of both sizes the twins. For those readers who are un- units arc singles. The racing machines, of scrambles engine has been increased. familiar with the general layout of A.M.C. too—the 348 c.c. 7R A.J.S. and the 498 As far as the two road-racing models are roadster engines it may be said that the c.c. G45 Matchless twin—are well to the concerned there is, of course, a continu- singles have light-alloy cylinder heads, fore in sporting circles and may be seen ance of the firm's policy of incorporating pushrod-operated overhead valves and in appreciable numbers at most national the benefits of experiments carried out wire-wound pistons. A chain-driven and international road-race meetings. on the factory racing machines during the Lucas rotating-magnet magneto is For 1957 no sweeping changes are an- previous season. mounted in front of the cylinder base and nounced for any of the models. Never- Liberal use of synthetic-rubber O-rings a separate dynamo behind the crankcase. theless, progress has been made in several and a special mainshaft -oil seal behind On the twins, separate cylinder barrels directions. All models are fitted with the the final-drive sprocket are the means and light-alloy heads are used and valve- new gear box and clutch described in The adopted to ensure oil-tightness of the new clearance adjustment is effected by means Motor Cycle for May 24 last. Meticulous four-speed gear box. Wedge-shape rubber of eccentric rocker spindles; the third attention to oil sealing is a notable charac- blocks in the clutch centre serve as a crankshaft bearing is a split, white-metal- teristicwww.ajs-matchless.info of the design of the box, while the transmission shock absorber. The un- lined bush in the middle of the shaft. clutch is claimed to be unaffected by the usual method of clutch operation The new method of petrol-tank em- presence of oil on the friction faces. It is employs a ball and roller between which bellishment on the twins consists of claimed that the performance of all the works a suitably profiled floating lever. separate, chromium-plated side panels roadsters has been stepped up without loss Adjustment is effected by a screw and fixed to the tank by the two screws which of tractability. Appearance of the twins lock nut in the centre of the clutch pres- retain the plastic motif and by two more is brightened by a new method of petrol- sure plate. Access to the adjuster and screws which hold the kneegrip plates in THE MOTOR CYCLE, 27 SEPTEMBER 1956 3 position. Plastic beading round the edge In adopting Girling shock absorbers for damping is continued for 1957. On both of the panel seals the gap between it and the rear springing, A.M.C.s are one of shock and recoil movements the hydraulic the side of the tank. Colours of beading the last manufacturers to take advantage check is more progressive in action, with of the specialized products available in the result that front-end pitching is said this field. Incorporating a three-position to be eliminated. adjustment for load, the units are similar To prevent the possibility of chatter A modification to the to those fitted to several other makes of occurring after an extensive mileage has twin-cylinder machines machine, but the upper and lower attach- been covered, and to provide an added concerns the oil-filter ments are specially made for the Plum- degree of resilience in the transmission, end cap which is now stead models. a considerable alteration has been made to of one-piece construc- At the bottom of each shock-absorber the five-pin drive of the quickly detach- tion as shown unit is a rubber-bushed, cast light-alloy able rear wheel on all the roadster yoke. The top fixing takes the form of models. Previously the driving (and a single eye containing a rubber sleeve. braking) torque was transmitted to the As the A.M.C. shock absorbers embodied solid pins bolted in the full-width, light- and tank enamel are very well blended yokes at both ends, the plain upper- alloy hub by their engaging with five so that the overall impact is most attrac- attachment ears formerly welded to the holes drilled in the malleable-iron casting tive. The 592 c.c. A.J.S. Model 30 has frame loops have been replaced by box- which serves the dual purposes of chain a royal-blue tank and light-blue beading, section lugs. Thus the new units are not sprocket and brake drum. The radius at while the six-hundred Matchless G11 has interchangeable with the old. Another which the pins are disposed from the hub a dark-red tank with black beading. On minor departure from normal Girling axis has been doubled, while the pins both five-hundred twins (A.J.S. Model 20 practice is the use of polished light alloy themselves are hollow and of much and Matchless G9) the tank is enamelled for the split collets which retain the upper larger diameter than before; each pin is black; the beading on the A.J.S. is light spring shroud. rubber sleeved externally. In the brake- blue and that on the Matchless is red. Incidentally, to provide added frame drum casting the holes with which the Tank finish on the single-cylinder stiffness for sidecar duty on the twins and pins engage take the form of tubular models is unaltered. In other words, the 498 c.c. singles, the bolt which clamps bosses, about fin long, which are con- tanks are enamelled black on a Bonder- the rear-frame loops to the top of the nected by an annular rib. ized surface and subsequently lined by seat tube is increased in diameter to 5/8in. A year ago the tool kit, battery and volt- hand. Lining in the case of the Match- Also the attachment point has been age regulator were grouped in a large box less models is in silver and for the A.J.S. moved forward slightly so that the lug which fits snugly in the left-hand rear machines in gold. Plastic tank badges on the main frame member is formed frame loop and matches the oil tank on similar to those on the twins are fitted. integrally with the rear tank-support lug, the other side of the machine. Hinged When output permits, tanks with panels whereas previously two separate lugs were along its bottom edge, the lid of the box will be offered on the singles at extra used. could not be opened fully if the model charge. A mid-season alteration to front-fork was fitted with a sidecar because of the proximity of the upper rear sidecar con- nection. To overcome the difficulty the Stark scrambler—the 497 c.c. G80CS Matchless lid is no longer hinged to the box. In- stead, two ears are formed at the lower edge of the lid which engage with slots in the box. Hence the lid can be com- pletely detached from the box irrespec- tive of the nearness of a sidecar connec- tion.