The Harley-Davidson Museum has pulled the covers off discarded prototypes of a leaning three-wheeled motorcycle developed by The Motor Company.

Harley-Davidson commissioned automobile hot rodding legend John Buttera to build the original prototype (pictured above) in 1998. Codenamed the “Penster”, the Trike looks like it could have been an earlier version of the Can-Am Spyder, but it had a tilting front end similar to the Piaggio MP3.

According to The Kneeslider, Harley-Davidson filed a patent for the leaning front end which uses hydraulic actuators to tilt the trike and return it to a vertical position.

Harley-Davidson spent years refining Buttera’s design, and in 2006, two years before Buttera died from complications of a brain tumor, produced the orange version pictured below.

The updated version has  a wider stance than the original, perhaps to allow room to place the foot controls further forward. The orange version also has vertically aligned shocks that leaned along with the front wheels instead of the horizontally-positioned suspension on Buttera’s original concept. The seat is also noticeably higher on the newer version.

It’s hard to say how close the Harley-Davidson Penster came to going into production. It appears Harley-Davidson decided to go in a less dramatic direction with the Tri-Glide Ultra Classic in 2008, a non-leaning trike with two wheels at the rear and resembles a conventional Harley-Davidson motorcycle from the seat forward.

The Harley-Davidson Penster leaning trike prototypes are currently on display at the Harley-Davidson Museum in Wisconsin as part of the “Collection X” exhibit, featuring several rare items and engineering experiments.

[Source: The Kneeslider, Harley-Davidson ]