Hello from Norman Oklahoma! Motorized Fixie


New Member
Local time
4:04 AM
Oct 23, 2016
Norman Oklahoma
Hi, I'm Kyler!
I've been prowling the forum for the last month as I've been working on my first motorized bike project. It's been fun, I've already destroyed one engine and replaced it. These Chinese Engines need a little TLC before you slap them on the bike. Fingers crossed I have it right this time.
A little bit about me. Im a student at OU in Civil Engineering, and I have an obsession with Opel Gts. I have three of the cars and they run too! Here's a picture of one of them I've restored.
So now about my bike build,
The bike I started with is a Raleigh back alley that I've been cruising on for two years. Best bike I've ever had. I've never had to work on it once! Until I put an engine kit on it haha. It's a single speed bike.
So I ordered my first kit from Iglobalbuy on Amazon. This kit was actually really good quality except for the hardware as with every kit. I had to drill out the old mount studs after they broke inside the case. Pretty simple job to drill them out and tap them for 1/4" x 20 all thread bolts. This kit was a total pain to install on my fixie though. Nothing cleared! Front tube was too big for the standard mount, pedals hit the engine when mounted low without spacers on the motor mounts, the exhaust hit the pedals, but the chain did clear haha. All of this was fixable though by raising the engine, denting the exhaust and slightly tapering the pedal cranks with an angle grinder. What wasn't repairable was when one of the piston rings decided to escape the cylinder and cracked the jug and damaged the piston. Anyway here's how it looked on the first engine. I briefly ran without a tensioner by equalizing both chains tension at the wheel. Also the sprocket is a fixie sprocket pressed into and welded to the 44tooth sprocket. It's held on the bike with red locktite and the lock ring. No problems with loosening in the last 100 miles!

I blame the engine failure on myself, I went through 2 tanks and then wanted to see how fast it would go. 42MPH with the wind behind me! A week after that it made a clanging noise one time at 10mph it didn't run again:(
So then I ordered an engine only from Gasbikes... bad mistake. The head was missing a cooling fin, the cnc head I ordered had gouges in it because it was packed without being wrapped. The engine also had broken studs out of the box ugh. Still waiting for this to be resolved. I replaced all the hardware with stainless allen bolts and studs. Cleaned out all of the metal shavings from the combustion chamber, clutch cover and magneto. Installed an NGK wire and spark plug, engine mounted chain tensioner, rubber on all mounts, and a Manic Mechanic type motor mount. Guess what? More clearance issues. This time it was only the exhaust hitting the pedals and the motor mount. Yall are going to laugh, but I made an exhaust out of copper flex pipe and copper RTV. No leaks, less power at low rpm, much quieter and It no longer sprays oil all over my bike or drips it on the ground. I love my janky exhaust! I'm trying to properly break this engine in this time, but after one tank it's doing 25mph at about half throttle in very short bursts.
Here's a close up of the engine and sprocket. Engine is painted with VHT engine primer, paint, and then clear.

That's all I have for now! About the only thing I plan on getting is a reed valve. After that some Indian Boardtrack handlebars, seat post and a leather saddle.