How difficult is converting a Motorcycle to a Motorized Bicycle?

[Devil's Advocate]

I've been looking at lots of various bicycles as the starting point for a new project, but when I look at the things I want, I wonder if i'm better to start with a smallish lightweight motorcycle and convert it to pedal power and put a 49cc two stroke in it.

Can anyone tell me how difficult it would be to convert the motorbike to pedal power? And also to adapt the 49cc motor chain drive sprocket to a motorcycle wheel? I did see an old thread here where a guy had done it with an old Honda, but his was electric so i'm not sure if the mechanics are the same.

I'd like to model it along the lines of the Yamaha FS 1E which was a 50cc moped produced in the 70's.





They are highly collectible now though and worth big bucks, so I can forget about using one of them.



But there are plenty of other bikes, not much larger, that I think would convert well.

A 70's Yamaha LT3 Enduro is selling near me for $300, it gives me suspension, comfort, big brakes, big tank, decent lights and indicators, all it needs is pedals and a chinese two stroke

 

[wheelbender6]

Because motorcycle frames are much heaver than bicycle frames, we never pedals added to them.
I dig the looks of small vintage motorcycles too, like the Honda S-90, but I just don't see the advantage of
adding bicycle pedals to them. They are two wide and too heavy to pedal.
If you want to go fast legally on a motorized bicycle, add a screaming 49cc motorcycle engine like an 11hp Moto Morini is your best bet. The Moto Morini is not a bolt-on. It will require welding for mounts and exhaust.

 

[butterbean]

For what it would cost to restore a small motorcycle like that AND add pedals to it, your better off doing the opposite. Find a good, strong bicycle frame and turn it into a light motorcycle. That's what I'm doing. 1956 Roadmaster boys frame, American made, brazed, double top bars, very strong. Suzuki hydraulic motorcycle forks, club handlebars mounted upright. Custom built wheels, motorcycle drum in front, moped drum in rear, both laced to 24" bicycle rims with 11g spokes. Custom lighting and charging system, led front and rear, high/low for headlight, tail/brake combo for rear, small battery and friction dynamo with scooter rectifier for charging the battery. 79cc predator as the power plant, and speed all depends on gearing, I'm geared pretty low and will cruise at 30mph but they can be geared much faster if so desired, I just don't desire.

 

[Wolfie65]

The difficulty of converting a motorcycle to a bicycle is nothing compared to the difficulty you would have of pedaling that hellishly heavy contraption. Better hook up a harness for about 6 sled dogs to help pull.I don't know if they still make them, but Austrian company Puch used to manufacture little Mofas ('Motorfahrrad' = motor bicycle), that were - or still are - extremely popular, especially with young people.They're basically small mopeds with bicycle pedals, so you could kill the engine and pedal it like it's a bicycle, important on some European streets where ANY type of engine noise is prohibited, such as near hospitals, retirement homes, etc.