The Enfield company are the latest recruits to the standard machine policy ; it being possible to purchase a machine almost identical with the actual racer. The only modifications being an 8 in. back brake and a 21 gallon petrol tank. The engine is a two-port J.A.P., modified to include the Enfield lubrication system. Enfield forks and brakes are fitted, and it is interesting to note that about half a dozen prominent trade entries in the races are also using Enfield brakes.
A Sturmey Archer close ratio gear-box is used with a gate change. Dunlop wired-on tyres are fitted, and a small tank drips oil on to the rear chain. The machines have quite racy lines, and in the hands of C. H. Young and J. G. Burney should perform well. The 250 c.c. machines are similar, except for tyre sizes and gear ratios.
Since Motor Sport road tested the 350 c.c. Royal Enfield J.A.P., this company has produced a similar model embodying an o.h.v. engine of its own design. The chief feature of the design is the neatly enclosed and lubricated overhead valve gear, a feature that should occupy designers' attention far more than it does at present. The Royal Enfield big twin sports machine is also shown-but is the same as last year's model barring a few minor improvements.
There followed a 346-c.c. o.h.v. Royal Enfield, having a single-port J.A.P. engine adapted to Enfield mechanical pump lubrication with but one external oil pipe. Providing the B. & B. carburetter was flooded the engine started easily and ticked-over at an incredibly slow speed. Semi-T.T. bars, Terry saddle and adjustable footrests gave a comfortable riding position, but the gear-lever controlling the three-speed Sturmey-Archer gearbox was badly placed, necessitating bending forward to reach it. Steering was delightfully light, road-holding excellent and in town, fine acceleration notwithstanding, this Royal Enfield was notably unobtrusive. Yet it would do 45 m.p.h. in 2nd gear and 60-65 m.p.h. in top.
A sweet, smooth clutch and the Enfield rubber-block cush-drive transmission, coupled with excellent balance, made feet-up manoeuvring easy at a snail's pace. Both the internal expanding brakes worked really well, although care was needed for a smooth stop from the rear one and the pedal was rather too high above the footrest. At first excessive oil supply caused plug oiling, but this was cured by cutting down the supply, while petrol consumption was approximately 90-100 m.p.g., riding fairly fast. Altogether this £50 sports model created a very good impression, although frequent oiling of the push-rod cups was required and the rockers relied on grease cups.
However, the following month Motor Sport got another machine out of a manufacturer. It was an 8-h.p. Royal Enfield and sidecar, looking very "vintage." It proved a great top-gear runner, pulling away smoothly and accelerating briskly from low speeds in its highest ratio. The brakes were another feature - enormous drums on both wheels, pedal-operated, so that either wheel could be locked even on a dry road, whereupon the Enfield upended, putting all retardation on the front wheel. Normally used, these were admirably smooth brakes.
This Enfield was the side-valve sports model, not the older 8-h.p. V-twin with touring bars and handle-starting that was sold only as a sidecar outfit, although foot-boards still figured in the specification, likewise, balloon tyres were standard wear. Hill-climbing was another strong feature of the Enfield, Kop, in really rough condition, being topped at about 80 m.p.h. in second gear in spite of a baulk on the first steep pitch. However, nothing mechanical is completely perfect and this combination used oil at the rate of 200 m.p.g., no ready adjustment of the mechanical pump being provided, yet, in spite of ample lubricant, two momentary seizures were experienced.
Moreover, speed wouldn't rise above 55 m.p.h., the gearing seeming on the low side, although a small carburetter jet may have caused the sluggishness and over-heating, as fuel consumption worked out at some 60 m.p.g. Comfort was good in spite of a rather high saddle position, the front fork action admirable and the sidecar, so low and racy as to be rather unsociable, aided stability on l.h. corners. Indeed, with passenger, the tyres could be screamed on such corners before the sidecar wheel lifted.
The sidecar was very comfortable, had ample leg-room and an efficient screen, and a locker that would accommodate a tool-kit and a two-gallon petrol tin or, as the tester pre ferred it, two one-gallon oil tins! Right hand corners gave rise to a rather wilting feeling and the front wheel tried to go straight-on if the surface was loose. However, the tester was decent enough to say that he was apt, "imbued with the spirit embodied in the title of this journal, to drive all test vehicles in a distinctly hectic manner as though life were one great race." Through ordinary hands the Enfield would have passed with flying colours.
He even rode the machine solo in a hectic grass track affair and made fastest time in the s.v. class. Moreover a mild crash, due to a locked front wheel, failed to damage the Enfield in any way. It proved capable of high averages, largely by reason of its excellent brakes, and sold for £84.
In spite of the rather frank admission of testing-methods contained in the Enfield test, another bicycle duly came along, in the form of a 350-c.c. o.h.v. Humber. Such factors as car-style mudguards, a sensible lifting handle and substantial build and excellent finish were apparent at first sight. The gearbox gave ratios of 5.65, 7.75 and 11.59 to 1, and in spite of a weight of 260 lb. the Humber steered exceedingly well and cornered really fast.
The 75 by 79 mm. engine used an M.L. magneto and a B. and B. carburetter, and equipment included knee-grips and a comfortable saddle; the price was £60. The Bonniksen speedometer showed 68 m.p.h. as the best registered, but it was felt that 75 m.p.h. should be possible under good conditions; 40-45 m.p.h. could be kept up with no sign of overheating and the only criticism was a vibration at 35 m.p.h., the only trouble in a week's riding a broken outer inlet-valve spring. Both brakes were smooth and powerful. The easy gear-change was a most notable feature; incidentally, the throttle lever opened inwards.