Introducing the Acme Mark II Motor Bicycle


Nov 24, 2012
Maricopa Arizona

Straight from the labs of the Acme MotorSport Corporation, the maker of the popluar MkIV Rocket Sled(Coyote sold seperately), comes the next iteration of fine motorbikes, the MARK II!! This fine machine is built on the frame of the finest (circa 1993) Scott UniTrack CST mountain bike sporting a pair of (old school) RockShox for frontal suspension, running a top of the line Dax Gen IV 66CC powerplant, and LEB Speed Carb, tuned to (almost) perfection using a TOP SECRET method and the industry leading SBP Expansion Chamber! Though still in the break in phase, this bike promises a bright future, tuned and geared for best performance in the 20-30 MPH range with maximum fuel efficiently and maximum bang for the buck while offering a (current) top speed of 35 mph.
Sporting a bare metal Chrome Moly steel frame and borrowing the ergonomic and efficient control design of engineer KC Vale this machine is sporty AND comfortable while looking very manly at the same time!

My parents always said I should have gone into marketing...

So I thought I would start another build post, though technically the build is done. If anyone remember my prior threads, I had a BikeBerry motor running on a Gary Fisher comfort bike. Well, on an awesome ride around Lake Mead with Massdrive (see thread my piston needle bearings decided they wanted to be free and managed to wreak havoc on my piston and jug while trying to escape. Thank God for a wife who will willing to pick me up! I was lucky though and had ordered a new Dax motor the week before and had it waiting for me a the Post Office.
After mounting it on the same frame and riding it a bit, I stumbled across an old school Scott Unitrack CST for $50 on Craig's List that I thought would make a good motorized bicycle. Doing some research I found that it was top of the line for its time, has a front shock, and is Chrome Moly, whereas the Gary Fisher was midrange, no shocks, and aluminum. Though it sounded like a good investment, I already had a good bike, so I was a little leery of buying it, but I did, and regretted it, until now.
The handlebars sat so far forward that it was uncomfortable to ride, the handlebars themselves were a weird wrap around that looked like a giant C. So I had to get a different stem and handlebar setup. I ended up damaging the shifter/brake controls trying to remove them. I found someone selling some old parts on Craig's List and got a cheap stem and some bars for $10. After changing the bars out, the cables were then too short for the higher handlebars and the shifter/brake levers did not lend themselves to a new arrangement with the clutch/throttle controls. So I started digging in the forums looking for an answer. I found a post that KC Vale had done on how he sets up his multispeed bikes and decided to go with that. So I removed the front derailer and cables altogether, opted for a twist shift for the rear derailer and installed a dual pull brake lever. I love the simplicity of it, thanks KC. I also hated the Barney Purple paint and the decals of ever little feature the bike had, so I decided to strip ALL the paint and go for the industrial/RatRod look of naked steel, which I think looks cool.
The one thing I was having issues with was routing the expansion chamber. On my old bike I ran it up and under and it worked perfectly. But the Scott didn't have the frame to pedal clearance for that configuration. So I had to go the high route. However I didn't have the right materials for the job. So Massdrive, being the cool friend he is, stepped up and help me put together an exhaust that fits right above the head and doesn't burn my legs. So after going above my meager budget I finally got the bike I wanted and then some. After a few finishing touches I was able to take the bike out yesterday and it ran great! Even better than the old one. The engine still has only about 100 miles on it or so, but already it purrs like a kitten and had plenty of get up and go. I am excited to see how well it will run when she is fully broken in!


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Feb 1, 2010
Nice clean no frills build, me likey. Just the
same, you won't catch me ordering anything
from Acme. Their stuff never seems to work out.:-||
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New Member
Oct 3, 2013
Las Vegas
Just want to say again what a great time I had working on your new bike with you. Even though I'm pleased with the results and glad you are too, still it ticks me off that I put all that time and money into my engine and your A.C.M.E. Mark ll is faster...
It's back to the garage to refit the Rattletrap...