N.S.U.
The most radical alterations in the N S.U. designs will be found in the 3½ h.p. engine, 85 by 88 mm., 499 c.c. The prototype of this engine was first seen in England at the Tourist Trophy Race. The magneto is placed behind the cylinder, is of the latest Bosch enclosed type, and is gear driven. On the gear wheel nearest the engine-shaft is a cam operating the exhaust valve, and on the next gear wheel to it is that working the overhead inlet valve. Both tappets are adjustable, but the exhaust valve has an adjuster on the valve itself; this consists of a foot screwed on to the bottom of the valve stem and secured by a lock nut. To adjust it two spanners are used. If the adjuster be unscrewed the foot is forced against the tappet and lifts up the valve stem, thus enabling the valve to be easily extracted. To replace the valve it is only necessary to hold the adjuster in position, to insert a screwdriver in the valve head, and force the valve down against the spring on to the adjuster. This is a process which is far simpler and easier than compressing the spring and inserting a cotter pin through the slot in the valve stem.
The latest type of N.S.U. automatic single lever carburetter will be fitted. Riders, so Mr. Schink. the manager of the company, informs us, are not quite used to controlling this carburetter, since they try and use it as an ordinary non-automatic carburetter by throwing the throttle full open. Like all carburetters of this type, the throttle cannot be fully opened until a high speed is attained, and when the lever passes a position over 45° from the handle-bar any further opening means a weaker mixture, which will not give increased speed unless the engine is turning over at a large number of revolutions.
The engine pulley is fitted with an oil-retaining ring, any waste oil being carried away through a drain pipe. The 3½ h.p. model will be fitted with a drop frame.
For 1912 the N.S.U. spring fork has been simplified and made more efficient, and in every model the rear portion of the frame will be sprung.
On the 3 h.p. twin the under-geared pulley is adjustable. The 6 h.p. twin, 75 by 90 mm., 796 c.c, is built up on the same lines as the 3 h.p., but the engine is now placed vertically in the frame, and not with the rear cylinder vertical, as was the case in former models. For this machine a new two-speed gear hub been designed on the same lines as the smaller gear, but it is larger and stronger, and improved in detail. In this and the smaller two-speed gear the pulley flanges are adjustable, which is a decided improvement. Both flanges may be moved at will, but the inner flange need only be altered in cases of emergency. The outer flange is secured by a locking ring, and between it and the movable flange is a loose ring which has a projection in it engaging in a slot, the object of which is to allow the adjusting ring to be turned without revolving the movable flange. As soon as the correct adjustment is obtained it is not necessary to secure the locking ring, as the pressure of the belt is sufficient for this purpose. The gear is also fitted with a large metal cone clutch provided with oil grooves and three extra plates for the engagement of the low gear. The planet wheels are carried in a cage and are supported at both ends, and an oil-retaining ring is provided. The 3 h.p. twin, 58 by 75 mm., and the 2 h.p. single cylinder machine will be the same as last year's models, except for the improvements above referred to in the spring fork design, which is common to all models.
1911 Olympia Show - The Motor Cycle November 2nd, 1911. Page 1157
N.S.U., No. 104.
The N.S.U. Motor Co., Ltd., Great Portland Street, W. – The frame, which has the top tube dropped at the rear, has a specially strengthened head which is made of a steel stamping. The engine is carried in a loop, as in all other N.S.U. 1912 models. The rear portion is sprung, which improvement was introduced at the last Olympia Show. The engine has the radiating fins cast horizontally with the ground. Overhead mechanical inlets are fitted, the tappet rods of which are adjustable, while the exhaust valve spring is provided with a special adjustable cap which allows the tension of the spring to be varied and facilitates the removal of the cotter and the valve itself. The N.S.U. two-speed gear is of the type described in a recent issue of The Motor Cycle, and has an adjustable pulley. Foot-rests are provided. A model similar to the above is strengthened where necessary, making it specially suitable for side-car work. In the case of this machine the rear spring is enclosed; this casing serves to lock up the rear spring portion, as it is not possible to employ it when a sidecar is fitted. If the machine is desired to be used as a single the casing may be removed by undoing four bolts. One of the sidecars shown has a large cylindrical tank at the rear carrying an extra supply of petrol. The sidecar has a wide wing of the car type and new front for the footboard to protect the passenger's legs from draught.
This machine is particularly suitable for solo riding, and is thoroughly up-to-date in every respect. The top tube of the frame is dropped at the rear and is sprung both fore and aft. The front forks have been slightly altered so that the cap of the spring under compression is used as a lamp bracket. The engine is provided with the same valve arrangements as on the twin just described, and as in all other cases the magneto is carried at the rear. The carburetter is the well-known N.S.U.
3 h.p. twin cylinder N.S.U. with undergeared pulley. The bore and stroke are 58 x 75 mm.
This machine has the ordinary type of frame with straight top tube. The engine is fitted with the N.S.U. valve gear, which has been in use for many years and has proved its excellence, while an under-geared pulley is fitted.
The frame is of the ordinary type with straight top tube, the magneto in this, as in all other models, is neatly carried behind the engine. The inlet valve is the overhead mechanical type, and is arranged similarly to that of the 3 h.p. twin. The frame is sprung fore and aft. In all models where a two-speed gear is not fitted an adjustable pulley is provided. The large type of gear has an adjustable pulley incorporated with it, while the small type of gear remains as before. The N.S.U. two-speed gear may be fitted to all models. The machines are examples of the very best workmanship, design, and finish.
1911 Olympia Show - The Motor Cycle November 23rd, 1911. Page 1269
