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Transmission

Transmission

Manual transmission

Harley-Davidson motorcycles have been offered with transmissions since 1915, when three gears were still sufficient for varying speeds and load requirements. The first four-speed gearboxes were introduced in the mid-1930s, the big twins were given five gears with the 1980 model year (the Sportster only ten years later), and since the mid-2000s six gears have been the standard for the Big Twins (Twin Cam and Milwaukee 8).

What was standard before the introduction of gearboxes?

For history buffs, let's briefly mention: like most other motorcycles in the early 1900s, Harleys had a direct connection from the crankshaft to the rear wheel, with (leather) belts. Instead of a clutch, the traction was regulated by the belt tension. From 1912 onwards the factory offered chain drive and a clutch in the rear wheel hub, and in 1914 two gears were added to the rear wheel hub.

Why do I need a gearbox on my Harley-Davidson?

It's because of the engine. Not specifically the Harley V-Twin engine, but the combustion engine in general. Every combustion engine has an optimum speed at which it develops the most torque. If the engine always has to pant through the rev range from zero to full load without a gearbox in order to cover all possible speeds, it rarely runs in the optimum range - or in other words: at only one specific speed. A transmission with several gears enables operation in or close to the optimum rpm range at different speeds. And the more gears a gearbox offers, the smaller the rpm drops are when shifting and thus yields a better gear connection. Tip: this is the reason why electric motorcycles like the LiveWire do not have a manual gearbox. Their torque is available from the first revolution across all speeds, so there is no need to shift gears.

Do all transmissions work the same?

At Harley-Davidson, yes, or at least largely similar. The factory has spared itself experiments such as chain or splined gearboxes and has relied on gearboxes with sliding gears and/or shift clutches right from the start. There are differences in the shape of the shift forks and how the gears are shifted up and down. There are also differences in the actuation: Manual shifting together with a clutch pedal was standard until the 1950s. The Sportster series always had only foot shift, the big Twins only from 1980 onwards. All Harley-Davidson transmissions are sequential, i.e. you can only engage one gear at a time, not skip gears like in a car.

What is available for your transmission at W&W Cycles?

We offer complete transmissions from Samwel for the 750 W models, and from Baker for the Big Twins with four-speed and five-speed shifting. Plus versions for custom projects such as four-speed gearboxes for the W models or six-speed versions for the Big Twin engines.

For all other models with air-cooled V-Twin engines, there are spare parts in original quality, accessories from Andrews, small parts, seals, PanAm oil

Have any questions?

Our service team will be glad to help out: Mondays - Thursdays 08:00-17:00 CET, Fridays 08:00-16:00 CET, Phone: +49 / 931 250 61 16, eMail: service@wwag.com