New project idea

It has been quite cold so I haven’t been riding my latest full suspension rig a whole lot, but I am very satisfied with it and I am continuing improvements and refinement.

I have a simple but excellent 12V lighting system, with bright lights front and rear. Yesterday I completed my brake light, rigging a bright red led to a simple 12V battery pack (4 AA batteries) to a simple switch attached to my rear brake lever. I soldered a metal spring and attached it to the throttle body with a small zip tie. I soldered a small metal washer and attached it to the brake handle. Another zip tie leads the washer to the spring when I squeeze. Simple and effective.

My financial situation is expected to be much better next year and my thinking is to buy a small motorcycle. But I have one more motorized bicycle idea:

I have a 140cc 4 stroke, taken from a lawnmower. I intend to convert it for horizontal use, welding on a oil slapped and closing and opening some holes. Should be very reliable. Would have to grind the drive shaft down from 7/8” to 3/4” for a chain driving centrifugal clutch.

I just snagged a motorcycle triple tree stem for a few bucks! I have a couple of nice springs that will fit the big tubes needed for the project so I am foreseeing a kind of plunger tube within a tube. I can make that work by chopping a headtube off a derelict steel bike and welding it to a cafe racer frame of my own design.

Researching pieces, I see that motorcycle fork tubes are very expensive.

I’m thinking that I can rig all this up, add all lights and mirrors and get a motorcycle tag. Has anyone done this?

 

[Musico336]

Lol so good

 

[Timbone]

I have a rolling chassis! Clip on handlebars work. Wheels are more or less complete. I still lack brake handles, drive sprocket, and a fuel tank. This bike looks a lot better with tires!

 

[JerboaJohn]

... If you could only increase the rpm from 3600 to maybe 4300 or 4500 instead of 5500 rpm

I'm just thinking what if the governor shaft button filed down just a tiny bit would raise the rpm needed before it pulls the throttle back.
like .020. I'm gonna try it at some point. I only want 4000-4200... just a smidgeon more rpm's hehehe

 

[Timbone]

Moving forward. I my clip on handlebars, brake levers, and electrical switches attached. I welded on a front wheel stabilizer/ fenderattschment to the front forks. I need to work out my lighting system, weld up my fuel tank and then attach the motor and 415 chain.

 

[Will'smotobikes19]

Looks cool bought a hemi 212cc today. Wondering If I should try to put it on my bike or the mini chopper. Planning on getting a billet flywheel, rod and heavy springs. Almost got a lifan 270cc but I saw the predator is cheaper and performance parts are available. That frame looks pretty good did you make sure when you welded everything was the right angle and true? the seat might need to be moved a bit forward but idk. I might change the seat on my micargi to a cafe style or banana seat. It keeps moving to the sides when I ride it. In fact the pedals aren't on it right now. Anything to get the seat position lower would be good.

 

[Timbone]

Sounds like you are into a serious project, too! 212 Predator is a fairly common project idea, so you should have access to lots of info that can help you with your build.

Personally, the idea of a Lifan 125 - with gearbox! - really appeals to me.

Yes my frame is perfectly true. It’s really easy to weld things up true when you are only working in two dimensions.

This thing is low and long, but not quite as long as it appears. Wheelbase is 56”! But my wheels are only 24”. I’m 5’11”, with a long torso and arms; the seat is exactly where I want it. My problem will be how to attach my foot pegs to the mainframe. I’ll figure something out.

I can’t understand your seat problem. Why would it move around?

 

[Will'smotobikes19]

Sounds like you are into a serious project, too! 212 Predator is a fairly common project idea, so you should have access to lots of info that can help you with your build.

Personally, the idea of a Lifan 125 - with gearbox! - really appeals to me.

Yes my frame is perfectly true. It’s really easy to weld things up true when you are only working in two dimensions.

This thing is low and long, but not quite as long as it appears. Wheelbase is 56”! But my wheels are only 24”. I’m 5’11”, with a long torso and arms; the seat is exactly where I want it. My problem will be how to attach my foot pegs to the mainframe. I’ll figure something out.

I can’t understand your seat problem. Why would it move around?

I guess the seat clamp isn't clamping hard enough. My bike is a stretched beach cruiser (micargi predator) so I'ts about 3 inches longer than a regular huffy or something. I will probably work on the motorized bike a bit more and get the pedals on and the matching rear wheel. I'd like to actually ride it instead of constantly working on it and putting around the yard with no pedals (it does not have enough power to get up the hill). The mini chopper has a 49cc 2 stroke on it but it looks like there's enough room for the 212. That will surely get up my mountain of a hill. There's a couple cheezy mounts for a fake engine which could be chopped and then a mounting plate welded in. I would have to get a new back wheel and tire with a left side sprocket. The forks are the original stiff Chinese ones complete with rust and peeling chrome. I do have some cnc aluminum grips left over which I'll probably use. I'm not sure if I could use one of the air shocks that gasbike sells in the front (1 1/8) but I have one laying around not doing anything complete with stem and origin 8 headset. I want to ditch the small gas tank and use maybe a 3 L peanut tank. I would get some gussets welded in the frame too. But anyways I'm looking forward to seeing your engine mounted up in the frame.

 

[Timbone]

Moving forward. I my clip on handlebars, brake levers, and electrical switches attached. I welded on a front wheel stabilizer/ fenderattschment to the front forks. I need to work out my lighting system, weld up my fuel tank and then attach the motor and 415 chain.

Progress continues. I’ve welded up my fuel tank, I’ve bought a 12v battery and I’ve attached a tail light to clean up the rear end.

I ran into my first real problem, though: I ordered a torque converter with a 41 chain drive sprocket. When I received it, I checked it with a piece of chain in the garage and I thought everything was fine for 415 chain. So I ordered 415 chain, cut it to proper length and attached it. It wasn’t meshing well, but I figured that’s because the teeth were a bit to wide and I could ground them down a smidge - chains vary - and all would be good.

But upon examination, the sprocket is for 35 chain! How did I miss that? I don’t have any 35 chain sprockets not do I have any long stretch of 35 chain.

So...I have a couple of 415 B sprockets for 1/2” axle. The TC has a drive shaft of 5/8”. Bought a 5/8” drill bit and ground down the dumb end of the bit to fit my drill motor. Drilled it out and ground the edges smooth.

So I’ll need to hand file a 3/16” key slot, add spacers and I’ll be good to go.

My axle sleeves will arrive Monday or Tuesday so I can quickly hook up a front brake and begin road tests soon.

 

[Old Busted Hotness]

I'm a little concerned about that swingarm. I think it wants a much wider pivot and two shocks so it can't swing side to side. To me it looks like it's going to fold up. Hope I'm wrong.

 

[JerboaJohn]

looks like work in progress. sure, couple chain stays to drop down from the seat mount to help with side loading. he has some great bikes from what I've seen.. can't wait to see what tank's goin on it! already lookin long and mean