Vintage Double Engine Drag Mini Bike

#1
Built by drag bike pioneer and howner of Hahn Racecraft, a very popular turbo kit manufacture. Powered by two 8hp Briggs&Stratton. He just posted this up on facebook, I HAD to share this with you guys.









And the story:

"In 1976, I was 14, and built a fun little number to race in the concrete alleys of my Chicago neighborhood. My friends were a bunch of dedicated, creative inner-city junior gearheads, cobbling together what we could with found materials and ingenuity.

Dad was 2000 miles away, so while his work inspired me greatly, I had to pull it all together on my own. With Mom's approval, and the assistance of a local machinist, this mini-tribute to the full-size multis of that era barked to life!

I won my races basically by default after that, for no one would take this new ride on. I was disappointed, to say the least. They basically all just said, "you are crazy, this proves it, so you win." Soon after, we'd discover that even though we were not yet of age to drive legally, we could still buy cars and drive them...well...illegally. We quickly forgot these juvenile home-made concoctions,moving right up to cars. But for a few years there, we terrorized those alleys!

Luckily, I've managed to hold onto this primordial machine for almost four decades. Soon, it will bark again. Sounds a lot like a 650 Triumph at full chat!"
 
#2
That is so kool. :thumbsup: This is the kind of stuff that makes me drool. This is old skool, do it yourself ingenuity at its best. :thumbsup: Thank you so much for sharing aarons. I bet this inspires you to get at your build. :thumbsup:
 
#3
i tell ya what, it inspires me to do something. the bicycle minibike freak is not gonna happen, this frame is just to pretty to cut up, so im using it for my other hobby, gravity bikes (check it out on the web if you dont know what it is)..

I have a $1500 tube bending set up and a brand new lincoln tig welder in my basement that I dont hardly use. Ive been thinking about building some vintage dragbike STYLE frames but for the minis, to use as pitbikes while im at the track. Or even just minibike frames in general.
 
#6
Aarons I say you should bend up some steel and weld up some frames. :thumbsup: Maybe you could replicate this bike? Or just make some of those '60s drag bikes, but mini. :shrug: Either way it would be cool.
 
#9
So the front motor is direct drive to the back motor?

On anything with 2 motors:won't the slower motor hold the faster motor back?No 2 engines are identicle output,right?

Please explain this to me:shrug:

And,that is one wicked cool bike!
 
#11
A qoute from the builder, Bill Hahn Jr.

"By the way, I saw your post on the oldminibikes.com asking about the clutch...that was something I scrounged in the scrap at a powerset company. It proved to be far too aggressive for this application, locking up too quickly in light of the super-tall gearing (the bike is geared for, and has gone, about 100 MPH). I will likely alter the gearing lower, and take some weight out of the the clutch when I get the old girl running again.

Some years after I built this, I was hanging out with friends, and and older, savvy one suggested I pour some oil in the clutch to get it slipping to voercome the premature lock-up. I scoffed, saying that would ruin it. He replied, "No, it will just burn it off and then lock up!"

Well, he talked me into it, and he was right! We got it out one day on the farm road by his house, and via trial and error, we figured out just how many squirts from an oil can to put in there before a "pass". The passes were actually pretty hilarious, we laughed so hard! At launch, I'd whack the throttle open, the engines would rev up and smoke would start POURING out of the clutch as it slipped. At about 40 MPH, it would finally lock up, no more smoke, 1:1 achieved.

I'm sure it did some damage to the linings, lol, and I"ll have to get a good look in there before I run this thing again"
 
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