Got forced induction? Harley-Davidson does, or at least it’s working on a plan towards that end.
This week, some keen-eyed patent crawler found a patent for a new supercharger system fitted to a Harley-Davidson Big Twin. You can check out the patent here. Skipping to Pages 3 and 4 of the patent, you can see the orientation of the supercharger, tucked behind the engine on the right-hand side of the bike.
The orientation suggests the supercharger runs off the bike’s transmission input shaft, but it actually runs off the crankshaft with the help of some intermediary gears. The patent seems intended to concern itself with the supercharger’s mounting and drive systems. The patent says “The crankshaft is rotatably supported in a case, and a supercharger is driven from the crankshaft by an endless drive member.” Later, it says “a mount has a track slidably supporting the supercharger relative to the case, so that tension in the endless drive member is adjustable and set in relation to the position of the supercharger relative to the case. The mount is self-adjusting to maintain an operating tension in the endless drive member.”
Boiling all that jargon down, here’s what is really going on, it looks like: Harley-Davidson wants to have a supercharger, but wants to more or less keep the same big-bore V-twin layout it’s used for generations. This patent technology makes that easier.
Why would Harley-Davidson want to develop this technology? Harley-Davidson is facing a double squeeze right now; big-bore bikes face restrictions from tightening emissions regulations, and manufacturers are looking at forced induction as a workaround solution. Harley-Davidson is also facing increasing competition from Indian’s more powerful motorcycles. A supercharger could allow Harley-Davidson to face off both these threats at the same time.