H-D hillclimber vintage design and modern engineering

[Fire-medic]

A unique bike, interesting how he did it. Sportster OHV top end on a flathead bottom end, and he switched the intake for the heads from one side of the bike to the other. The six-member rear frame triangle resembles a rare H-D factory modification from pre-WW II. The builder wants to hillclimb it to see what it was like 'back in the day.' Note the exposed valve train, very retro! A 72-tooth rear sprocket, and all the transmission's gear pairs have been disabled, except one.

http://www.revzilla.com/common-tread/magnum-45-hillclimber

 

[Traumahawk]

That looks WAY cool.

 

[sdt354]

A unique bike, interesting how he did it. Sportster OHV top end on a flathead bottom end, and he switched the intake for the heads from one side of the bike to the other. The six-member rear frame triangle resembles a rare H-D factory modification from pre-WW II. The builder wants to hillclimb it to see what it was like 'back in the day.' Note the exposed valve train, very retro! A 72-tooth rear sprocket, and all the transmission's gear pairs have been disabled, except one.

http://www.revzilla.com/common-tread/magnum-45-hillclimber

Very cool machine, and a popular mod in the early 60's when there weren't a lot of performance parts available. Sportster jugs on a 45 woke it up big. I'[ll bet those engines could top out at 110 mph with the right sprocket. Fast for the time. All the way to around 1970 the Sportster was king of the street & strip. They were everywhere. Strokers, duel engine builds, and excitement that rivals today.