help a noobie out with sizing

[cmh]

ok i searched for about an hour and its almost imposibile to find what im looking for. i have, what i like to call, a grandma trike. regular old school trike made by schwinn. i need to know what size wheel sprocket i need.

specs:
beach cruiser style trike
212cc predetor engine
11 tooth centrifugal clutch
#40 chain
24" wheels

ok so here is one problem. i weigh 280lbs and im 5'11" and i wanna go fast lol. the guy at northern tool sold me a 8 tooth wheel sprocket and i know that cant be right. the bike doesnt take off. its fast if u pedal the heck out of it and then press the gas. i want more of a "real" motorcycle feel. u know like gas and go. please help.

 

[Ibedayank]

ok i searched for about an hour and its almost imposibile to find what im looking for. i have, what i like to call, a grandma trike. regular old school trike made by schwinn. i need to know what size wheel sprocket i need.

specs:
beach cruiser style trike
212cc predetor engine
11 tooth centrifugal clutch
#40 chain
24" wheels

ok so here is one problem. i weigh 280lbs and im 5'11" and i wanna go fast lol. the guy at northern tool sold me a 8 tooth wheel sprocket and i know that cant be right. the bike doesnt take off. its fast if u pedal the heck out of it and then press the gas. i want more of a "real" motorcycle feel. u know like gas and go. please help.

8tooth...ummm you need about 12-1 gear reduction


you need a jackshaft
11tooth clutch to a 22tooth on jackshaft then 11 tooth otherside of jackshaft to 72 tooth sprocket on axle will give you 20mph at the governer limit of 3600 rpm no need to pedal like mad before hitting the gas

 

[nastygramus]

want to go faster BUY A MOTORCYCLE just saying

 

[cmh]

8tooth...ummm you need about 12-1 gear reduction


you need a jackshaft
11tooth clutch to a 22tooth on jackshaft then 11 tooth otherside of jackshaft to 72 tooth sprocket on axle will give you 20mph at the governer limit of 3600 rpm no need to pedal like mad before hitting the gas

thanks... not sure what all of this means but now i know what to tell the guy to sell me..

 

[cmh]

want to go faster BUY A MOTORCYCLE just saying

thanks for ur expert opinion... ill stick to finishing my bike.

 

[nastygramus]

lol sorry if I offended you and your right I dont have a clue about these bikes good luck with your build

 

[cmh]

^^^ not offended at all... just wondering why in every forum someone has something negative to say... it was my fauly to ass-u-me that u were that guy...

anyhow,@ ibedayank or anyone else that knows, i have a stupid question. how come regular bikes(two wheel) dont use the jackshaft method but every setup i see on a trike does? am i missing something? trust me i have read i just cant seem to figure it out.

i thought it was as easy as running a chain from the motor directly to the axle of the bike and just trying out different size sprockets till u find one that works... right now u cant see it ,but im wearing my face of shame...lol

 

[diceman2004]

Jack shaft ... i don,t have a trike , but my guess is that most motor kits run off the left side of the rear wheel . ( on a sprocket attached to the spokes )

you wouldn't be able to do that with a trike . ( you need to drive the axle )

Typicaly , the sprocket on the axle is offset to the right to line up with the pedal sprocket , so you need a jackshaft to transfer the drive ( from the left side of the motor , to the right side of the bike )

Like i say .. i don,t know because i don,t have a trike ( but i would imagine you would also need some sort of shift kit that would let your pedal sprocket freewheel while the motor is running )

 

[thegnu]

Typicaly , the sprocket on the axle is offset to the right to line up with the pedal sprocket , so you need a jackshaft to transfer the drive ( from the left side of the motor , to the right side of the bike )

the jack shart kit has a freewheel front chain ring thats how its made possible . sickbikeparts.com find the hd jackshaftkit.

 

[Ibedayank]

yeah and a coaster brake hub will handle the power of a HF 212cc motor
think about this for a minute

the motor is mounted BEHIND him

set up the motor to the axle like a gokart and it will be much simpler and last longer
be cheaper to replace parts as they wear out

 

[thegnu]

hey theres always some fab work to do !

 

[cmh]

hey guys... thanks for all ur responces. ill try that next. what i did was buy like a 8" sprocket. i have to count the teeth to be sure but it seems to be working fine. problem now is that its rolling so fast that the tire is falling off the rim.lol. its also rolling towards the right like it needs an alignment. im going to weld the two axles together to see if that helps.

also, the chain keeps falling off. i think its because the difference in sprocket sizes is so big its hard to tension the chain so imma add a tensioner. ill take pictures asap, its just taken apart again since those two thing keep failing on me.

 

[Ibedayank]

do NOT weld the axles to gather you will never be able to turn it

 

[thegnu]

do NOT weld the axles to gather you will never be able to turn it

I'm glad someone mentioned that !

 

[cmh]

lol... im glad u mentioned that too... what do u suggest i do about the tire ripping off...

smaller diameter but wider wheels? imma finish this ting this weekend no matter what so im searching for solutions and advice before my trial and error session.

thanks again in advance.

 

[thegnu]

Have you checked the bead of your tire an rim ? your rims bead may be too shallow or slippery try sanding it on the inside to give the tire something to hold onto , also the bead of the tire may be too shallow or worn , make sure the 2 are seated properly , a tire not centered on the rim can come off.
Gary