issues

[r_chez_08]

Hi,
So today I finished converting my mini bike to part chain drive. However, now the sprocket is too close to the ground! it hits on bumps and tight corners

I either need a smaller #40 sprocket (i have 54t) or a larger wheel (preferably) for the rear. Does anyone know where to get a larger than 11" rear tire for a 4" hub?

Cheers
Rob

 

[anderkart]

Whats the actual tyre size (printed on the sidewall) now?

 

[r97]

Do you mean a 4" rim, or are you looking for a 4 bolt hub with a 4" bolt circle? I assume you have already figured out what (if anything) needs to be done with your gear ratio after you change the tire dia.

 

[Jcotz]

Do you mean a 4" rim, or are you looking for a 4 bolt hub with a 4" bolt circle? I assume you have already figured out what (if anything) needs to be done with your gear ratio after you change the tire dia.

If the size of the back sprocket is that close to the size of the back tire, then he probably has room to gear steeper. IMO

 

[r_chez_08]

Never mind guys, I know what I am going to do now.

I have a jackshaft from a torque converter. I have a 65mm pulley on the torque converter js going to a 140mm pulley on the second jackshaft.
Then I have a 25t pilot bore sprocket I bored and keyed to fit as the jackshaft output, then a 54t sprocket on the wheel. Final ratio is about 4.7:1.

I am going to machine the 25t pilot bore sprocket to fit the wheel so it can bolt up. I will then get an 11t sprocket and machine that to fit the jackshaft. Then have no clearance issues and I still have a similar ratio.

My tire size is 11x4-4 iirc.