About Me:I’m not really new, but I have a new board name, and I just finished building my first bike last week. Primary purpose for wanting to build a Motorbicycle – When I was a kid, I wanted to mount an old lawn mower engine on bicycle – Now I’ve done it!
The Kit & the Bicycle
I bought a 2 stroke “China Doll” kit from BoyGoFast on eBay over a year ago. Unfortunately, the engine didn’t fit inside the Mountain Bike I had intended as a donor bicycle, so I went on Craigslist and bought a used Beach Cruiser for $60. Then I broke an engine mount bolt off while trying to replace it with all thread as recommended on a FAQ on these boards. Then my wife had a baby, then we moved, so the kit sat in a plastic storage bin, and I sold the beach cruiser.
Back on the job a year later, looking at Craigslist again, I found a small company selling beach cruisers for $100 right here in my neighborhood.
Broken Bolt:
I guess I could have taken it to a machine shop, but from what I understand, this is a fairly common occurrence, so I resolved to figure out how to do it myself.
I broke at least 5 drill bits in the process and snapped 2 bolt extractors. What finally did the trick, was heating up the metal with a Benz-o-Matic torch I had for doing plumbing work, and used an engraving bit on my Dremel tool that I had for building model airplanes. I am also now the proud new owner of a small Craftsman tap & die set.
Grinding Therapy
After spending at least 4 sessions in the garage getting the engine mount fixed, I had to grind out the sprocket to fit on the rear hub, then I had to grind down a retainer cap to fit inside the sprocket. After all of that was settled, I put the brake arm back on, but now the brake arm didn’t match up to the frame.
Taking my trusty Benz-o-Matic torch, I clamped down the brake arm to my work bench with a pipe wrench (I don’t have a vise anymore), heated it up, and bent it this way and that with a 2 pound sledge hammer.
The Build
The rest of the build went fairly smoothly. My top tube was larger than the mounting brackets for the gas tank could handle. I spent a session in the garage one evening trying to fabricate some metal brackets, but just wound up with some seriously mangled metal at the end of the evening. Then I went down to the auto parts store to see what I could find, and came out with some flexible muffler hanger metal.
At some point, I went back to the plastic storage bin to see what other parts needed to be put on, and there weren’t any – I was done!
Test Rides
The first couple of test rides were really hard. I couldn’t get the engine to turn over more than a few times if I wasn’t pedaling, and I could only pedal so far with the clutch out. Finally, I found a paved path in a park that went downhill, and just kept going up and down it until it developed enough power that I could keep the engine going on flat ground.
That Look
Even though I live in SoCal, it is amazing at the looks I have been getting driving around my neighborhood. For the most part – women scowl at the noise, and men grin from ear to ear.
It's a fairly routine build as far as motorbicycles go, but I figure you build your first one to know what you want in your second one. I received several compliments on it when I rode it to a pickup game of soccer in the park last Sunday, and last night I was just sitting in the garage smiling and looking at it while listening to the radio.
It's like I'm 16 again, and just got my first car.
The Kit & the Bicycle
I bought a 2 stroke “China Doll” kit from BoyGoFast on eBay over a year ago. Unfortunately, the engine didn’t fit inside the Mountain Bike I had intended as a donor bicycle, so I went on Craigslist and bought a used Beach Cruiser for $60. Then I broke an engine mount bolt off while trying to replace it with all thread as recommended on a FAQ on these boards. Then my wife had a baby, then we moved, so the kit sat in a plastic storage bin, and I sold the beach cruiser.
Back on the job a year later, looking at Craigslist again, I found a small company selling beach cruisers for $100 right here in my neighborhood.
Broken Bolt:
I guess I could have taken it to a machine shop, but from what I understand, this is a fairly common occurrence, so I resolved to figure out how to do it myself.
I broke at least 5 drill bits in the process and snapped 2 bolt extractors. What finally did the trick, was heating up the metal with a Benz-o-Matic torch I had for doing plumbing work, and used an engraving bit on my Dremel tool that I had for building model airplanes. I am also now the proud new owner of a small Craftsman tap & die set.
Grinding Therapy
After spending at least 4 sessions in the garage getting the engine mount fixed, I had to grind out the sprocket to fit on the rear hub, then I had to grind down a retainer cap to fit inside the sprocket. After all of that was settled, I put the brake arm back on, but now the brake arm didn’t match up to the frame.
Taking my trusty Benz-o-Matic torch, I clamped down the brake arm to my work bench with a pipe wrench (I don’t have a vise anymore), heated it up, and bent it this way and that with a 2 pound sledge hammer.
The Build
The rest of the build went fairly smoothly. My top tube was larger than the mounting brackets for the gas tank could handle. I spent a session in the garage one evening trying to fabricate some metal brackets, but just wound up with some seriously mangled metal at the end of the evening. Then I went down to the auto parts store to see what I could find, and came out with some flexible muffler hanger metal.
At some point, I went back to the plastic storage bin to see what other parts needed to be put on, and there weren’t any – I was done!
Test Rides
The first couple of test rides were really hard. I couldn’t get the engine to turn over more than a few times if I wasn’t pedaling, and I could only pedal so far with the clutch out. Finally, I found a paved path in a park that went downhill, and just kept going up and down it until it developed enough power that I could keep the engine going on flat ground.
That Look
Even though I live in SoCal, it is amazing at the looks I have been getting driving around my neighborhood. For the most part – women scowl at the noise, and men grin from ear to ear.
It's a fairly routine build as far as motorbicycles go, but I figure you build your first one to know what you want in your second one. I received several compliments on it when I rode it to a pickup game of soccer in the park last Sunday, and last night I was just sitting in the garage smiling and looking at it while listening to the radio.
It's like I'm 16 again, and just got my first car.
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