Ive decided to do another build. I'm hoping to have it set up like a dirt bike with the same clutch, gear and braking style controls. Do you think its possible to do this setup with a dirt bike engine and transmission? 
Can it be done?
- Thread starter Cycloptishred
- Start date
just about anything can be done with the right tools and ingenuity. Things I would worry about are...
1) What do you plan using the bike for? If you plan to go offroading, you probably would be better off getting a dirt bike and riding it as is. Dirt bike frames are much stronger than bicycle frames, you don't want it folding up on ya. Do you plan using a bicycle frame or starting from scratch?
2)What size engine? The engine size will have to correspond to the bike. For instance, I wouldn't suggest putting a 450 into a walmart special. Heck I wouldn't suggest putting a 450 into any bicycle. Frame may have to be gusseted. Many db motors are fairly wide, this will have to be considered. Do you plan on keeping the pedals?
3)How do you plan on mounting it? Mounts would probably have to be welded and maybe even gusseted. I wouldn't even think of using a rag joint, I'd go to worksman wheels with either a grubee hd hub of a disk brake hub with sealed cartridge bearings-Attach sprocket by threading on the grubee or bolting on disk, possibly with top hat adapter.
4)Random bits. Stock bike fork probably wont be strong enough. DB or moped rims might be a good option if not worksman wheels. DB brakes or bicycle disk brakes should be used, not the commonly found bicycle callipar brakes. Make sure to get a motor-frame combo that will work. Might be a good idea to mod the frame to get the motor to sit lower to improve handling. Some reinforcing migh be in order.
All in all I think it could be done. I was thinking of using a 74 yz 100 for a motorized bicycle. But there wasn't much around for it and the stock gearing kinda sucked so I went the 212 pred route. It would be a sweet set up, motor and trans in one unit. My main consern would be a frame, wheels, and brakes that can handle whatever motor you choose to use. It's definately doable though.
1) What do you plan using the bike for? If you plan to go offroading, you probably would be better off getting a dirt bike and riding it as is. Dirt bike frames are much stronger than bicycle frames, you don't want it folding up on ya. Do you plan using a bicycle frame or starting from scratch?
2)What size engine? The engine size will have to correspond to the bike. For instance, I wouldn't suggest putting a 450 into a walmart special. Heck I wouldn't suggest putting a 450 into any bicycle. Frame may have to be gusseted. Many db motors are fairly wide, this will have to be considered. Do you plan on keeping the pedals?
3)How do you plan on mounting it? Mounts would probably have to be welded and maybe even gusseted. I wouldn't even think of using a rag joint, I'd go to worksman wheels with either a grubee hd hub of a disk brake hub with sealed cartridge bearings-Attach sprocket by threading on the grubee or bolting on disk, possibly with top hat adapter.
4)Random bits. Stock bike fork probably wont be strong enough. DB or moped rims might be a good option if not worksman wheels. DB brakes or bicycle disk brakes should be used, not the commonly found bicycle callipar brakes. Make sure to get a motor-frame combo that will work. Might be a good idea to mod the frame to get the motor to sit lower to improve handling. Some reinforcing migh be in order.
All in all I think it could be done. I was thinking of using a 74 yz 100 for a motorized bicycle. But there wasn't much around for it and the stock gearing kinda sucked so I went the 212 pred route. It would be a sweet set up, motor and trans in one unit. My main consern would be a frame, wheels, and brakes that can handle whatever motor you choose to use. It's definately doable though.
being a motorcycle has the rear brake on a foot pressed lever I do not see how this can be safely done while still having pedals. With out working pedals its just a motorcycle
