Tranny comparisons for frame mounted motors

the secondary sprocket takes up a little room so you will loose a few pedal gears , but you wont need the big ones , just make sure your rear bundle threads on , then get a new gear bundle with fewer gears to make up for the room you will need , you might have to stretch the bike frame just aliitle and ad another spacer nut on the axle , you will need a scooter freewheel with the four bolt pattern about ten bucks , and a bearing cup for a bottom bracket , the threads are all the same , you will see , play with it , it works , i like the 8mm chain but you can use other sizes but you will find that drive sprockets and large chain rings come in tons of sizes in the 8mm . if you go half inch bike chain your choices will be limited
 
Last edited:
..

thanks scooterguy! that's a neat cassette you made. i'm going to go with the 5 to 1 tranny from thatsdax and i guess put an 11 tooth sprocket on it. i'm in the process of trying to put another cassette and derailer on the rear tire, on the other side from the original, for engine shifting so it won't interfere with the normal bicycle shifting. might work and it might not and too much tourque might break some teeth. i'm enlisting the help of a cyclist friend for this one. i'll let you know how it goes.
 
hmmm

that's a great point. didn't think about that.:rolleyes: guess i'm gonna have to problem solve that one. glad you said something so i can figure it out without putting it on first and seeing that it doesn't work. for my final build i want the NuVinci internal hub but i'm just playing with parts i have until i save up enough money. that things expensive but from what i've read well worth it. especially for the long trip i'm planning.
 
That's a great looking bike! Defintly worth puting the money into that internal hub. And with the cassette I'm thinking maybe I could fix it so it doesn't freewheel at all. I don't see any reason for it to since the engine only spins one way. Any thoughts?
 
this is my thought , the 5 to 1 tranny , is designed to power the right side of the bike , if you flip it around to drive the left side it will spin the wrong way also , you motor will need to sit way to the left of the bike to drive the left side of thewheel . other than that you really dont need a freewheeling cassette . you will still be able to pedal fine . what i would do , is use the one to one no reduction no reverse the spin tranny , it uses the # 25 chain its pretty small , but it drives the left side of a machine , use the 6 t drive down to i think its a 84 t . the clutch on the motor will do the rest . i will get you a link for that tranny .
http://www.scooterparts4less.com/web_gas/47cc_3rdBearing_GearBox.htm
 
My transmission went out on my car today so my focus has suddenly gone from playing with the rear derailer to just getting something that will utilize my engine and bike and get my ridding. As much as I hate to do it, I'll have to come back to playing with the derailer. I'm thinking a cvt with a 7:1 ratio and 20 t sprocket down to a 41 or 44 t. here is the cvt i'm thinking about http://www.monsterscooterparts.com/cvtwichco.html sorry to switch gears (no pun intended) on you.
 
3 to 1

thats a 3 to 1 tranny , it doesnt turn the drive around , that will drive the left side fine , the sprocket it comes with is a 8mm . you will have to use a large chainring to match it , but it will work . just remember , thats a 3 to 1 not a 5 to 1 reduction for the gear ratio. there are half inch drive sprockets but the smallest you will find is an 12t in steel drive sprocket , hope you get it going , bikes have been taking me to work for a long time.
 
Back
Top