Do you need a reduction gearbox?

[Conor]

Hey Guys, totally new to building anything to do with motors or bikes.

Im planning on putting together a fat tyred bike build with a Honda GXH 100 motor and a centrifucal clutch.
will i need a Reduction gearbox? or can I just link up the sprocket straight to the clutch?
any help is greatly appreciated.
Thanks

 

[mark20]

Hey Guys, totally new to building anything to do with motors or bikes.

Im planning on putting together a fat tyred bike build with a Honda GXH 100 motor and a centrifucal clutch.
will i need a Reduction gearbox? or can I just link up the sprocket straight to the clutch?
any help is greatly appreciated.
Thanks

Yes you will need a reduction of some kind. Atleast a 15:1 if im correct. So a 44t sprocket with a 5:1 belt drive. Or a 56t with a 3:1 chain reduction. Id suggest using 1/4in steel and 5/8 keyed rod. Then set it up it up for about 4-5:1 (10t clutch to a 50t sprocket use #35 chajn here) to a then a smaller #41 chain sprocket to tou rear wheel (then use a motorized bine sprocket, 44t)
And if that makes sense. Your done!

 

[Conor]

Thanks so much for your help.

A few other things I should mention
( the motor is a GXH50 not 100, my bad), im not looking for it to be street legal, just want it to go fast. Will be driven of road.

The URL below is what gave me the idea for my build, would something like this not work?

I have just been having trouble finding these reduction gearboxes here in Australia.
https://bike.belkihayat.com/motor-para-triciculo-transporte-legal/

 

[mark20]

Thanks so much for your help.

A few other things I should mention
( the motor is a GXH50 not 100, my bad), im not looking for it to be street legal, just want it to go fast. Will be driven of road.

The URL below is what gave me the idea for my build, would something like this not work?

I have just been having trouble finding these reduction gearboxes here in Australia.
https://bike.belkihayat.com/motor-para-triciculo-transporte-legal/

It could, but your engine is a lot bigger.
I have a clone of that engine on my daily driven cruiser bike. Your better off putting it in the frame as it tends to twist a lot. Putting in the frame reduces a lot of stress on the drivetrain and the frame it self (lot more meat on the main triangle then the chain stays) mine is geared pretty low as i tend to go in more offroad then on road, i also built it so it could pull a fully loaded bike trailer with no issues. Still goes about 32mph on the roads

 

[Conor]

Ok sounds good
I was thinking about getting rid of the original drivetrain and just leaving the pedals there as a foot rest. Also I was planning on welding a rear rack over the back tyre to hold the motor, most of my riding will be on the beach and I was thinking it might be good to have the weight over the back tyre.
Basically where I live your not allowed motorcross bikes on the beach but no body really cares about bicycles aha. I'm just trying to rig up a bike that looks like a bicycle but a tad like a motorbike to not aggravate to many people

 

[Conor]

*acts like a motorbike

 

[mark20]

Ok sounds good
I was thinking about getting rid of the original drivetrain and just leaving the pedals there as a foot rest. Also I was planning on welding a rear rack over the back tyre to hold the motor, most of my riding will be on the beach and I was thinking it might be good to have the weight over the back tyre.
Basically where I live your not allowed motorcross bikes on the beach but no body really cares about bicycles aha. I'm just trying to rig up a bike that looks like a bicycle but a tad like a motorbike to not aggravate to many people

Yea im guessing you could just weld up a rear bracket and call it good. Just be sure to use a gear reduction unit. And it should work out just fine!
(I wouldnt cut the pedals off, kinda defeats the perpose of it dont you think?l