Cast nickel iron front brake drum is used on the Big Twins and the rear wheels of Servi-Ca
To further improve the shifting on the 45 twins and Servi Cars, the clutch release lever has been increased in diameter from 9/16” to 3/4”. Deflection of the lever has been minimized and more of the movement at the clutch pedal is transmitted to the clutch throw-out bearing. A more positive throw out of the clutch is assured and gear wear is reduced.
Smooth clutch engagement in starting and the elimination of chatter are obtained in the 45 twins and Servi-Cars with a clutch key ring that features six inserted flat springs. This design provides a cushion take-up action and prevents the plates from grabbing and rattling.
There are four slotted spring keys on each lined disc assembly in the big twin clutches. These slotted spring keys fit into the keyways of the clutch ring and take up slack and prevent rattle.
A keyed, sprung steel disc is incorporated on all big twin clutches. This keyed disc has been in use for some months. It improves clutch action and reduces chatter.
The front end of the 45 Twin now presents the same appearance as other models in the line
For 1940, the 61 OHV, 74, and 80 twins will be regularly equipped with four speed forward, all-sliding clutch transmissions. This constant mesh transmission makes possible rapid shifting and is therefore popular with sport and competition riders. To accommodate police and commercial users who are operating in traffic, Harley-Davidson will continue to offer the same three speed, and three speed and reverse transmission, with sliding gear in low gear position, that has been available in the past.
The flange on the drive side of the interchangeable wheel hubs is now a carbon steel forging instead of a stamping. Increase in strength is obtained. This new hub is standard on all wheels except the front wheels on the 45 and Servi-Cars.
New streamlined semi-circular design footboards for 1940
Better electrical contact is secured in all 1940 models by the use of new flange-type copper terminals which supplant the usual type soldered twisted wire terminals. Copper metal exerts a tension when placed under pressure which is absent in solder. The result is a contact which conducts the current without loss of effectiveness. These new terminals are used throughout all the models in the line except in the lamps and a few other places where space forbids their use.
Spark plugs for 1940 will be fitted with insulators. The new insulators have been used for some time and have demonstrated that they are less subject to cracking, add to plug life, and help render better plug performance.
The clutch foot lever bearing cover on all models has been redesigned and more securely mounted to prevent noise and rattle.
Brake shackle fork stud on all models is longer and is positively secured with a nu and special lock washer. Lubrication has been made more convenient by changing the location of the Zerk-Alemite fitting.
Stop light is standard on all 1940 models. Formerly it was an extra charge item included with equipment groups.
The regular saddles on all 1940 models are covered with a smooth-finish, full-grain cowhide leather specially tanned. The leather is soft and flexible as well as water-proof and the color is a beautiful brown.
Holes in rocker arm fingers have been changed to insure positive lubrication
Buddy Seats for 1940 will be fitted with a thick cushion of whipped latex (rubber) . The top covering is the same full-grain cowhide used on the regular saddles. The valance is walrus grain with the back cut out more to give required guard clearance. Three red crystal ornaments decorate the valance. Increased padding in the front end of the saddle gives the rider real comfort when riding two up. When riding solo, there is no tendency to slide all over the saddle.
The high tension spark cable in the 1940 models are made of Neoprene, the oil-resistant, synthetic rubber. This rubber is also extremely resistant to heat. This all means longer cable life.
The sidecar chassis for use with the 45 twins is now fitted with a hinged, rubber-mounted front connection. Riding and handling qualities are decidedly improved.
The front stand on the Big Twins has been redesigned and is now interchangeable on all models.