parts from donor bikes – other parts people would
drop off and great deals he just couldn’t refuse.
Arlen had a brand new 1946 Harley-Davidson 74ci
UL Flathead bottom end that he picked up from a
shop going out of business. He could have easily
matched it with a 74ci top end but that wasn’t
his way. He loved to be different and push the
boundaries. He was already aware there were
Magnum motors out there (a Sportster top
end on a 45in Flathead bottom) but he had
never heard of a Magnum based on a big
UL 1200 bottom end, so of course, this
then was the challenge.
It wasn’t hard to find a 900cc
Sportster top end. The engine was
loosely cobbled together and mounted
in a rigid ’57 frame with a narrow glide
front and 21in wheel and down
back, a 19in rim with a tire
off some antique car Arlen
came across. Using a big
rim and tire off a car
preceded the fat tire
craze by quite a few years
so it would have certainly
stood out, even more so
since Arlen was so known
for his trademark “Long, low
and lean” Diggers at the time.
It did mean re-locating the axle
plates back and up to be sure the
bike would sit properly slammed even
with the high tire.
Arlen and Jeff, his chief mechanic, put
a fair amount of time and effort into the
original Magnum 30 years ago but other projects
and distractions came along and the Magnum fell
by the wayside. Fast forward to 2018 and Arlen
decided it was time to finish it. He stayed true to the
original concept, even to the point where he person-
ally polished the 19in antique wheel and scrubbed
the old tire (which would have been over 50 years
old) until they looked brand new. The Sporty top
end was mated to the UL cases but re-engineered
to work much better than they thought possible
“HE HAD NEVER
HEARD OF A MAGNUM
BASED ON A BIG UL 1200
BOTTOM END, SO OF
COURSE, THIS THEN WAS
THE CHALLENGE.”