Motorbike project

Putting parts together to build a motorbike.

 

[Gordy]

That's a beautiful frame, but I'll tell ya now it's gonna be a royal PITA putting a motor on. You're gonna have to make yourself a lot of custom parts just to get the engine mounted.

 

[Deleted member 36128]

Yeah, with the crankset removed there’s a flat spot to mount up to a plate, I’ll have to weld the plate on that bottom tube. I laid the motor on the bottom rail and it seems to fit well.

 

[Sidewinder Jerry]

You should put a mounting plate roughly where the green line is. This'll give you a lot of options on where to position the engine.

 

[Gordy]

Yeah, with the crankset removed there’s a flat spot to mount up to a plate, I’ll have to weld the plate on that bottom tube. I laid the motor on the bottom rail and it seems to fit well.

It will be easier with a four stroke, but still expensive. Is that a predator 212?

 

[Deleted member 36128]

Predator 79
I’m not looking for that much power.

 

[Deleted member 36128]

You should put a mounting plate roughly where the green line is. This'll give you a lot of options on where to position the engine.

View attachment 214590

I’m gonna put the torque converter on and see how it works out with a sprocket on the rear wheel.

 

[Sidewinder Jerry]

I’m gonna put the torque converter on and see how it works out with a sprocket on the rear wheel.

With a 79cc 4 stroke and a CVT, you'll need to use 10t/60t sprockets. Or you can install a double sprocket jackshaft on the seat post. Then you can use this setup

3~1 CVT 10t >> JS [30t | 18t]>> Rear Wheel 36t

With the smaller sprocket in the rear you could use Damien's setup for a rear disc brake. If you go with the larger sprocket you'd have to use either a drum brake or a rim brake.

With either set up, the reduction range would be 18\1~6\1. With a stock engine using 26" wheels, you should have a top level ground speed of 44 mph and a cruising speed of 35 mph.

 

[Deleted member 36128]

Thanks for the sprocket ratios, that’s all good to know.
I have a 30 torque converter, using a 5/8 to 3/4 shaft tube, a ten tooth from the converter to a 48 tooth on the rear hub. I already have this stuff so I’m gonna try it.
Thanks again for the info, played with motorcycles but never tried this stuff.

 

[Sidewinder Jerry]

Thanks for the sprocket ratios, that’s all good to know.
I have a 30 torque converter, using a 5/8 to 3/4 shaft tube, a ten tooth from the converter to a 48 tooth on the rear hub. I already have this stuff so I’m gonna try it.
Thanks again for the info, played with motorcycles but never tried this stuff.

If your CVT could make it to the 1\1 using a 10t\48t with 26" wheels it would give you a speed of 58 mph. Without some serious mods to the engine this isn't going to happen. Then should you encounter a steep hill climbing it would be very difficult due to not having enough torque. The reduction range would be 14.4\1~4.8\1.