4H.P. TRIUMPH.

Sturmey-Archer Three-Speed Countershaft Gear Model.

Engine 85x97 m.m. = 550 c.c.

TYPE H.

This Motor Cycle has been entirely re-designed and is fitted with a 3-speed Countershaft Gear. The new engine gives greater power than those of previous years, while the easy starting is a special feature due to the improved decompressor. The Carburetter is nearly automatic, both for starting and driving at all speeds the air lever should be three-quarters of the way open.

4 h.p. Triumph

With Sturmey-Archer Three-Speed Countershaft Gear.

TYPE H.

SPECIFICATION.

Engine. - Triumph, single-cylinder, 4 h.p., 85x97 m/m bore and stroke, volume 550 c.c, entirely re-designed; main shaft runs on ball bearings; roller bearings to big end of connecting rod; decompressor; large M.O. valves, interchangeable, with straight through air draught between valve pockets and cylinder; new design external valve gear; adjustable tappets with vertical lift; efficient silencer with extension pipe to rear of machine (Prov. Pat. 24214/14).

Three-Speed Countershaft Gear and Free Engine Clutch. — Sturmey-Archer three-speed countershaft gear; friction clutch providing free engine on each gear. Handle-bar clutch control, kick starter, entirely enclosed. Standard Gears : 5, 8¼, 13½ to 1

Carburetter. - Triumph new pattern semi-automatic carburetter, very economical (Prov. Pat. 24213/14); registered design handle-bar control (Reg. No. 513548/07).

Ignition. - High-tension magneto; handle-bar control; chain-driven (Renold), with oil and dust-proof aluminium case for chain.

Frame. — Exceptionally strong, made from very best quality weldless steel tubing, dropped at back to give low comfortable riding position; fitted with Triumph patent spring forks (Pat. Nos. 12165/'05 and 24648/'10).

Wheels. — 26 in., extra strong rims; back wheel easily removed.

Tyres. - 26in. X 23in. Dunlop heavy, front; extra; heavy, back; or 700 X 65 m/m Clincher de Luxe extra heavy, plantation rubber.

Transmission. - Chain-cum-belt, ⅜ in. Renold chain from engine to gear box, enclosed and adjustable, thence by Triumph 1in. rubber V belt running over large pulleys.

Tank. — Extra strong, fitted to lower horizontal, tube; hand lubricating pump; needle valves to main petrol supply and injector; large and quickly detachable filler caps; patent petrol gauge (Cox's Pat. No. 9679/'05) readable from saddle. Capacity: Petrol, 1 ½ gallons; Oil, 2 ½ pints.

Mudguards. — The front mudguard is fitted with side wings; the back guard is improved and carried low, and all fittings are very substantial.

Brakes. - Registered design foot brake, acts on the inside of belt pulley, and operates from left side foot lever. Front rim brake is operated by inverted lever on handlebar. The shoe pads are of special composition, giving a powerful grip, and are non-glazing.

Handle-Bar. - This is made from high carbon steel, well swept back, and with dropped ends to give a comfortable riding position; provided with two independent fixings in frame head.

Carrier. — Light and strong tubular construction; all lugs and crosspieces are brazed. No clips.

Stands. — Back, and front, mounted, independently of hub spindles.

Footrests. — Carried well forward, and giving a very comfortable position. These are adjustable, and fitted with substantial rubbers.

Saddle. — Improved Brooks-Triumph, padded top, large size, well sprung, and very comfortable.

Toolbags. — Two leather pannier bags securely fitted to sides of carrier. Tool-roll with complete set of tools supplied with each machine.

Finish. — Enamelled in best black enamel on Coslettised frame; all bright parts heavily plated. The tank is enamelled grey, and artistically panelled and lined.

We reserve the right to modify or deviate from specification in minor details.

Prices include a leather bound Log Book, containing many riding hints and other useful information, and also includes insurance coupons against accidents, &c.

Power Unit.

We built the first Triumph Motor Cycle Engine eleven years ago. At the time this was a mechanical masterpiece, and the pioneer of medium weight single cylinder engines, and proved an immediate and immense
success.

After satisfying ourselves that our original conception was correct, we have concentrated our energies and resources on this particular type, and from year to year have introduced many improvements which could only be gathered from long experience both on the road and in the workshop.

Our efforts have been crowned with success, for to-day it is recognised that the single cylinder has reached a point nearer perfection than any other type of motor cycle engine. During the last season more Triumphs were sold than at any other similar period in the history of the Company.

In view of the fact that so many sidecars are being fitted, we have considered it advisable to re-design the Triumph engine for 1915.

The bore and stroke are 85 X 97 m/m giving a piston displacement of 550 c.c., rated at 4 h.p., but developing considerably more when running under favourable conditions.

We were one of the first to introduce ball bearings to the main shaft, a practice now universally adopted. This factor has contributed in a marked degree to the flexibility of the Triumph engine, and we have now adopted roller bearings to the big end of the connecting rod.

Before introducing this we have given, same most exhaustive tests, and are satisfied, there is nothing superior for an engine of the capacity of the Triumph. It reduces friction considerably, thus adding to the flexibility and smooth running of the engine, it is easily and efficiently lubricated, and provides a wide bearing surface which will stand up to its work well nigh indefinitely.

The valves and ports are made considerably larger to allow rapid intake of the charge, and complete scavenging of the exhaust gases. These valves are placed side by side, a design which is far superior to placing the inlet valve directly over the exhaust, in which case, should the head of the valve snap, this will fall within the engine and possibly damage piston and cylinder. This contingency is not possible with the side by side arrangement, whilst being equally efficient and more accessible than the overhead type.

The exhaust valve is placed in the forward position, allowing the air currents to impinge directly on to it with the machine in motion, and the cylinder is cast with air spaces surrounding the valve, as a further aid to the cooling effect. Both valves are mechanically operated, thus providing a positive action, and the tappet rods are made adjustable.

Timing Gear.

This has been entirely re-designed and simplified. Only one timing pinion is employed, placed immediately over that of the mainshaft. Both valves are actuated off the one timing wheel to which are attached the inlet, exhaust, and decompressor cams. These cams are machined out of the one piece and, so formed to give ample lift and quick closing of the valves.

Long rockers are interposed between the cams and tappets, these working in hardened steel bushes, and the tappets are more substantial and provided with an easier setting.

The valve lifter mechanism,, including the return spring, is enclosed within the case, making the outside particularly neat and free from interstices to harbour oil, dirt, etc.

Cylinder.

This is a beautiful piece of workmanship. The walls and combustion head are made in one piece, so that there is no chance of leakage, which is inseparable from the detachable combustion head type, and at the same time the possibility of distortion to which the latter type is also liable, is eliminated.

The radiating fins are cast deep and thin, thus providing ample and equal cooling surface. These are not carried right down the cylinder, as the heat generated in the lower part is negligible, and can be dealt with effectively by the plain cylinder walls. This means a cleaner and cooler engine, as there are no deep recesses to harbour dust and dirt which, are both non-conductors of heat.

The interior is bored and afterwards ground to a surface like polished glass, the combustion head and valve ports are thoroughly cleaned up to remove any projecting particles in the casting likely to become incandescent under heat, and are designed free from all obstructions likely to impede the flow of gases.

Piston and Connecting Rod.

A very light casting is used for the Triumph piston. This is cast with interior webs to give the necessary strength to with stand the heavy explosions and heat without distortion, and increased bearing surface is provided for the gudgeon pin.
The most careful workmanship is employed on this important reciprocating part. The cylinder and piston are made perfect fits, and two rings are fitted to the top of the piston and one at the bottom. The lower ring ensures even wear of the cylinder walls and an adequate supply of lubrication reaching the cylinder walls.

The connecting rod is made from heat treated high quality steel, and is very light in weight. The hollow gudgeon pin carrying the connecting rod is hardened and ground to a driving fit in the piston, this eliminates any extraneous parts liable to come adrift and damage the engine.

This unusual method of fixing exclusively used in the Triumph engine is only made possible by the most accurate workmanship, otherwise some form of security device is required, and which all other makers adopt in some form or other. This detail alone goes to show the exact science brought to bear in the production of the Triumph motor.

Flywheels.

The fly wheels play an important part in the design of an engine. Weight misplaced, or unevenly balanced, will set up vibration and probably destroy the flexibility of the engine.

To obtain flexibility it is necessary that the majority of the weight be in the rims, but unless the fly wheels are made unduly large and bulky, this is impracticable from a steel forging without introducing some supplementary form of construction.

Steel forgings are used for the Triumph fly wheels, but to obtain the necessary weight at the periphery, the rims are drilled and loaded with a special heavy composition metal which is far heavier than the steel removed.

This method of construction allows a neat overall of fly wheel and crank case, all reciprocating parts are perfectly balanced, and an engine extremely flexible and one capable of quick acceleration is obtained.

Decompressor.

The cam for this is cut out of the same one pieces carrying the inlet and exhaust cams, and is operated by means of a small foot lever conveniently placed. The lever operating the decompressor is put into upright position for starting the engine and then pushed back for riding.

With the decompressor in action, the exhaust valve is slightly raised, thus reducing the compression and the principle adopted is so efficient that the engine can be started from cold with the first kick of the starter.

Triumph Carburetter

Prov. Pat. 24213/'14,

           and

Handlebar Control

Reg. No. 513548/'07

This carburetter has been specially designed for the new Triumph engine and is provided with top feed to the float chamber and jet placed between the piston valves. Although provided with two piston valves controlling the gas and air, this carburetter is automatic, the air lever being three-quarters open for starting and running at all speeds, it being necessary only to slightly reduce the air for extra steep hills.

The jet being placed central the air is drawn directly over it, thus ensuring a correctly mixed charge.

A fixed size of jet is employed as standard, which can be varied by fitting a larger or smaller jet if desired. Both piston valves are handlebar controlled. The air intake is provided with a gauze cover, and perforated metal cap. The illustration shows this carburetter entirely dismantled, and from this it will be noticed how extremely simple is the construction.

Sturmey Archer Three-Speed Countershaft Gear.

After subjecting the Sturmey-Archer Three-Speed Counter-shaft Gear to a. searching test, we have adopted this as a
satisfactory variable gear for the Triumph 4 h.p. Motor.

From the illustration it will be noticed that this is placed neatly in the bottom bracket position, evenly distributing the weight, and avoiding any complications in the removal of the back wheel.

Transmission from engine to gear box is by ⅜ in. Renold chain, thence by 1 in. belt running over large pulleys, thus ensuring a smooth drive. The chain is enclosed by an aluminium cover.

The gear box throughout is of a most substantial character. The gears are constantly in mesh over the full width of the teeth at all times, and on all three gears, the changes being effected by sliding dogs, consequently there is no danger of stripping the gear teeth.

Other advantages are that the gears may be changed at any time, i.e., whilst the machine is stationary or moving, with the clutch engaged or otherwise, and with the engine running or stopped. There is no need to declutch when changing gear, but it facilitates changing to lift the exhaust valve momentarily when operating the gear lever. If declutching is resorted to, it is advisable to completely declutch, instead of attempting to change with the clutch partly gripping.

Clutch.

The clutch consists of the main body (3150) keyed to the gear box axle and four other friction plates, two of which (3154 and 3156) are coupled up to the main body by the spring boxes (3158) and studs (3151) malting a total of five friction plates. The other two plates are the sprocket (3152) and the plate (3155) which are coupled to one another by tongues, and corresponding grooves in their peripheries. The sprocket runs on ball bearings, and so gives a perfectly free clutch when desired. The: sprocket and plate (3155) are drilled to receive a series of discs which project slightly above the metal surfaces of the plates, and when the whole is compressed by the six clutch springs within the spring boxes, it forms a solid coupling with a certain amount of elasticity in the drive.

The whole clutch may be readily dismantled by removing the spring box screws.

Gears.

The clutch body (3150) is keyed on the taper end of the main axle (3111) the central portion of which is formed with six keyways cut from the solid metal. The! central pinion (3120) has corresponding key ways and consequently is always rotated bodily; with the axle, although free to slide longitudinally. The gear wheel (3115) to which the pulley is screwed, revolves freely on the axle, as does also the small pinion (3121).

The layshaft (3128) has keyed upon it at one end the gear wheel (3130) and is also formed with four clutch dogs in the centre, into which may be engaged at will a corresponding set of clutch dogs in the
sliding pinion (3121).

The two sliding pinions are connected by a forked plate (3174) and so are operated simultaneously; the action is as follows :-

HIGH GEAR. - The sliding pinions are moved to the left, so that the clutch teeth on pinion (3120) engage with corresponding clutch teeth on gear wheel (3115) this locking the, latter to the axle, and giving a solid top gear drive. A recess formed within the pinion (3129) ensures that the latter is free from driving engagement with the layshaft.

MIDDLE GEAR. - The sliding pinions are moved to the central position releasing the high gear dog clutch, and permitting the clutch dogs on the layshaft (3128) to engage with the internal clutch teeth in the layshaft sliding pinion: (3129). The drive is then transmitted from the axle through the sliding pinions to the layshaft, thence by the left-hand layshaft pinion to the main gear wheel (3115).

LOW GEAR. - The sliding pinions are moved to the right, engaging the right hand clutch on the axle sliding pinion with the clutch teeth on the low gear pinion (3121), and releasing the clutch dogs on the layshaft (3128) from the layshaft sliding pinion (3129). The drive is effected through the pinion (3121) to the layshaft gear wheel (3130) and thence to the main gear wheel (3115) by the left hand layshaft pinion.

In all three gears, it will be noticed that each pair of pinions is continuously in mesh, so that there is no risk of chipping off portions of the gear teeth, which would eventually damage the whole gear box.

Both the layshaft and the main gear wheel (3115) revolve on ball bearings reducing friction to a minimum.

The Kick Starter.

The Kick Starter consists of a substantial lever (3136) fastened by a taper cotter to a short shaft (3135) which is machined out to receive a free wheel pawl (3138).

This communicates movement to a large gear wheel (3140) in mesh with a small pinion (3122) mounted on a squared portion of the main axle. When the pedal lever is returned to its normal vertical position, by the return spring provided for the purpose, a projection on the free wheel pawl comes into engagement with a fixed cam mounted in the gear box cover and positively depresses the pawl out of action. This ensures silent running of the free wheel mechanism assuring its continued efficiency, and prevents damage when wheeling the machine backwards.

The gear changing mechanism consists of a long ever pivoted on a stud at the centre of a notched quadrant, and retained in its various positions by a spring plunger. The forward position is low gear, then neutral (for starting up), middle, and high gear positions.

Lubrication.

Lubricate the gear with ordinary engine oil. After a first injection of about three oil gun charges, it should run one thousand miles before further attention, when another oil gun full can be injected (the gear is lubricated before leaving our works). If thin oil is used it will require replenishing more often. Do not use thick grease. The spring plunger and joints in the gear changing mechanism should be kept oiled regularly, and also the clutch worm. The, latter should occasionally be cleaned with paraffin.

Do not lubricate the clutch as this is designed to run dry.

Starting.

Place the gear lever in neutral position with the clutch in engagement. Start the engine by the kick starter, then declutch before engaging the low gear; after which the clutch may be re-engaged, and the other gears operated as desired. Do not forget to declutch before engaging gear, otherwise the machine will leap forward, and probably cause damage.

By placing decompressor in action, it will be found possible to make an easy start. It will facilitate starting by flooding carburetter, and injecting a small quantity of petrol through compression tap.

Adjustment.

The gear is sent out correctly adjusted, and should not need any further attention, except periodical lubrication. A means of adjustment, however, is provided in the short vertical coupling from the control lever to the gear box lever.

To adjust the gear, remove the top connection pin, and screw the top connection pin up or down. When correctly adjusted the gear lever should move an equally small amount either side of the neutral gear notch without engaging gear. A second neutral position will be found, although not marked on the quadrant, between middle and high gears.

When adjusting gears, rock the driving sprocket or pulley both ways to ensure movement of the sliding pinions into their respective clutch dogs.

To adjust the clutch, the wire stop screw should be screwed up until there is about 3/16 in. to ¼ in. of idle movement in the clutch worm lever. In extreme cases it may be necessary to loosen the clutch worm lever from the worm to find a more convenient operating position. The clutch should be adjusted immediately any sign of slipping is felt. Should oil get on clutch this will also cause slipping; to overcome, inject petrol. A sure sign of slipping is given by the clutch becoming warm whilst driving.

When fitting up the control wire for the clutch, ease off the bends as much as possible, to ensure long life and easy movement of the wire.

Triumph Motor Frame.

Particular attention is paid to the construction of the Triumph frame. For a number of years we have used the double horizontal top tube construction, and arc satisfied that this is the most suitable design for motor cycle frames, The entire head is made in one piece, and it embraces the two horizontal and bottom tubes, and only the; very best quality of steel tubing is used throughout. Although subjected to the severest usage on all manner of roads, this has failed to reveal a single weakness, in the Triumph frame. The rear portion is gracefully curved so as to provide a low saddle position.

The frame equipment is very complete, wide mudguards are fitted, giving ample protection to the rider. The front guard is provided with side wings.

The footrests are made adjustable, so as to meet the needs of riders of different heights, and are fitted with substantial rubbers.

The luggage carrier is of a light but strong tubular construction mounted independently of the rear hub spindle. There are no unsightly clips, all joints and crosspieces being brazed, and provision is made for affixing pannier toolbags to the sides, so that they are well protected from mud, and the top of carrier is left free for luggage.

Front and rear stands are both mounted independently of wheel axles.

Triumph Patent Spring Forks.

Pat: No. 12165/'05 and 24648/'10.

One cannot help but admire the great neat ness and strength which distinguishes Triumph Patent spring forks. To attain this, efficiency has in no manner been impaired. No shackles are employed, as in the majority, of spring forks, which prove a common cause for side play, and the only moveable joint in the Triumph fork, situated at the crown, is mounted on ball bearings.

A large coil spring is mounted at the top of the fork, which allows the wheel a wide range of: movement in a fore and aft direction and thoroughly insulates the rider from road shocks and vibration.

The substantial design of the crown, and the girder-construction adopted makes this fork tremendously strong.

Handlebar and Controls.

High carbon steel tubing is used for Triumph Handlebars. This is the most expensive steel tubing it is possible to procure but it possesses the virtue of being extremely strong.

We employ the usual head clip to clamp the steering column to the handlebar stem, but owing to the severe twisting strain to which the handlebar is subjected, this blocking is supplemented by bringing the handlebar stem into close contact with the steering column at the lower end. To do this the stem is coned out and split, and into this a coned shaped wedge registers controlled by a long bolt and nut terminating at the top of the handlebar lug.

With the indrawing of the wedge the stem is splayed and brought into close contact with the steering column so that these two - handlebar stem and steering column - form a homogeneous unit, and make it impossible to twist the handlebar on even the roughest roads.

Petrol and Oil Tank.

On many machines the tank is fastened to the top tube of the frame,  by means of clips. In addition to these being unsightly, the liability is for the clips to come adrift. For some time we have considered this method obsolete.

The Triumph tank is supported on the lower horizontal tube. Two lugs with platforms are brazed to this tube, and on this the tank rests cushioned by substantial rubbers. It is held in position by locking washers which pass through the lugs into substantial fittings in the bottom of the tank. This is an extremely neat and substantial fixing, and entirely dispenses with unsightly clips on the top of the tank and tube.

The tank itself is of a very strong construction, with but one longitudinal seam the end is riveted and the top edges gracefully rounded off.

The lubricating pump is concealed in the fore part, and all taps are dispensed with, needle valves being substituted.

Removable petrol and oil strainers are fitted so as to trap any foreign matter, the filler caps are large and quickly detachable, and a sump is provided to allow the last drop of petrol to be drained to carburetter.

An ingenious petrol gauge is part of the tank equipment. This is a patent device fitted inside the tank which accurately registers the amount of fuel in the tank. The dial is placed on the top so that it can be read from the saddle. The registering finger is connected with a spirally shaped spindle on which is threaded a cork running between suitable guides. With the rise and tall of the fuel the suspended cork brings the indicating finger on to the mark on the dial corresponding with the quantity of fuel in the tank.

Lubricating Plunger Pump.

Engine lubrication is effectively dealt with by means of a hand pump, conveniently placed within the reach of the rider. A great advantage with the hand pump is that it does not depend on any intricate mechanism, it is extremely simple, and the rider has a certain knowledge as to the amount of oil delivered to the engine.

One great flaw in mechanical lubricating systems is that oil is delivered to the bearings, according to the speed of the engine. At an average speed this works efficiently, and also with a higher speed when more oil is called for, and more delivered. It is when steep gradients have to be surmounted that the mechanical lubricator is defective, the engine is then turning over slower, more heat is being generated owing to generous throttle opening, and less oil is being delivered when most is necessarily required.

The rise and fall in temperature also has an important bearing on the amount of lubrication required, which the mechanical lubricator is unable to look after.

With the Triumph hand pump, the charge is forced directly into the crank case where it is distributed to all bearings, cylinder walls, and piston by the movement of the fly wheels and crank pin, and the amount of oil delivered is regulated according to the judgment of the rider.

The mechanism of the pump eliminates all taps, the action is positive, and the rider has a sure indication of a. full charge being drawn into the pump, as when depressing the plunger, a perceptible resistance is felt, whereas if only air is in the pump, only a certain resilience is experienced.

Brakes.

The foot brake has been entirely re-modelled. The shoe acts on the inside of the belt pulley, thus in no way interfering with the ready removal of the back wheel. The arm carrying the shoe pad is of ample length to provide a powerful leverage and is anchored to a special lug on the frame. The operating lever is conveniently placed over the left footrest.

The front brake is operated by an inverted lever on the right side of handlebar, and acts on the front rim. The brake pads are readily detached to facilitate wheel removal.

Tools.

A complete kit of tools is supplied with each machine, which includes spanners for every nut, a large adjustable wrench, pliers, file, and screwdriver; also a magazine tyre repair outfit, and valve extractor.

SPARE PARTS

Spare Parts specially recommended to be carried.

See separate Catalogue for Spare Parts and Replacements.