Motorin’
After almost two weeks of off-and-on work, I finally put the finishing touches on my newly motorized bicycle, and this afternoon, as I pedaled briskly down my street, I popped the clutch and the engine came to life. I have to make some minor adjustments to the carburetor to reduce the idle speed, but it seems to be doing what it was designed to do.
The engine is something I bought online for $124. It came with everything needed to convert a 26″ bicycle to a moped. As I wrote recently, however, my Schwinn–a gift from Jeff and Sandi in 2007–was just slightly too small to accommodate the motor. It turns out that many mountain bikes have small frames for their wheel sizes. Bikes designed for road use generally have great big frames with lots of clearance for an engine. Serendipitously, Sarah Jean had a bike laying around, and she just gave it to me. For nothing. The engine fit perfectly.
The kit came with comically mistranslated instructions. I made better progress when I discarded them in favor of photos of other motorized bicycles online. The throttle cable and carburetor cable gave me trouble, as did the chain, which required the removal of several links. I didn’t have a chain breaking tool, but I got the guys at Bikes and More on 6th Street to do the job for me. It was cheaper than buying the tool. Alas, they made it an inch too short, so I had to improvise my own tool (a nail set), and I put a link back in. I was extremely confused by what to do with multiple springs, and where the printed instructions included patently false information, a Flickr search showed me that one spring wasn’t mean to be used as a spring at all, but as a heat shield for the clutch cable.
I wouldn’t say that I was going the full 30 miles per hour this afternoon that some have claimed. It’s really hard to judge speed on a bicycle. Supposedly, if you make some changes to the exhaust system you can dramatically increase performance. But that would involve increased noise, and that’s the last thing I want. I’d be willing to sacrifice speed for less noise. As it is, right now it basically sounds like a chainsaw.
Getting used to the clutch and the braking system will be my biggest challenges now. Braking involves putting in the clutch to disengage the drive, then stopping as normal. But you have to remember to start pedaling before you pop the clutch again, or else you’ll stall. I think I am going to just use the engine when I have to go up steep grades, and when I have long straightaways where I don’t need to do a lot of starting and stopping. It’s going to make my life easier.
Filed under: Technology, Transportation on February 7th, 2009
i wish that everyone was as conscientious about the noise as you are…there are two or three guys who drive past our house every day on their motorized bikes, and it sounds like giant dragonflies are invading the neighborhood…but less whimsical.
I don’t want to be considered a local wanker. Moreover, I am vigilant about protecting my hearing. I wear earplugs when I vacuum or use a hammer. So, a loud motorized bicycle is unacceptable.
I personally endorse all aspects of this vehicle and it’s use.