The appearance of the machine is influenced by larger gas and oil caps. They are now big enough so that they may be easily removed even while wearing gloves.
The gadget we noted on the pipe turned out to be a gas deflecting muffler end. We were going to pick out something to kick about. This is it. Its utility value exceeds its beauty. Our sense of proportions rebelled at accepting the deflector as beautiful and the fact that it was finished in a black gloss and assertedly heat-resisting synthetic enamel did not altogether alleviate our injured feeling at finding such a curve on an otherwise well-streamlined job. However, we are willing to subscribe to the idea of deflecting exhaust gases. Who hasn’t wished for something like this when serving as a passenger in a sidecar or sometimes when behind a windshield?
The reason for the smooth-running motor is partly due at least to the new T-slot cam ground pistons and the new design of cylinders. Being cam ground, the pistons are no longer round when cold. They have practically no clearance on the skirt in line with the connecting rod thrust, but a clearance of .015 on each side in line with the piston pin. A vertical and a horizontal slot allowing for expansion is featured on each piston. When the pistons warm up, expansion deflects to the T -slots and to the sides and then the piston becomes round. Two diagonally-cut compression rings are incorporated in each piston. No cushion rings are used.
Cylinder bore is no longer tapered, but straight. Instead of a ground finish, cylinders are honed to a highly polished gun barrel finish. Naturally, friction and wear are minimized.
It can readily be seen that, properly functioning, the new pistons and cylinders are the answer to the absence of piston slap in a cold motor, and likewise that they give the best in compression when heated up. They contribute to easy starting and rapid acceleration even with a cold motor.
Easy gear shifting is to be attributed to constant mesh transmission. On the 45 the gear teeth are always in mesh and shifting is accomplished through dog clutches of ample size and design. Damage to gear teeth through chipping is avoided. Since the gears are in constant mesh the teeth are not rounded and full advantage is taken of tooth width. Jumping of teeth is eliminated and shifting is therefore easy and positive.
The external contracting rear brake of the old 45 Twin has been supplanted with a new internal brake on the right side of the machine. Pressure on the pedal is transmitted to the operating mechanism with no loss of effectiveness. The brake drum is carbonized and hardened and brake lining is harder and longer wearing. Combined with the front brake, the braking system on the new 45 Twin gives the rider the utmost in braking safety.
Noticeably different in design, the new streamline air intake does that which is obvious. It takes more air and makes for a more uniform mixture. It also facilitates acceleration and even performance at higher speeds.
Both front and rear brakes on the 74 and 45 Twins now carry an adjustable brake shoe pivot stud. Shoes can now be adjusted for full contact, assuring braking over the entire shoe surface, resulting in longer shoe life and better braking performance.
When riders of the new 45 have occasion to work on a rear tire they will probably make a few facetious comments to the effect that engineers have been out riding motors. The rear wheel is demountable with a knockout axle. The hinged portion of the rear fender may be raised, five mounting bolts removed, the axle nut taken off and the axle be pulled out. The wheel comes off, leaving the brake and chain adjustment intact. It should add much to the popularity of the 45 model.