Rugged off road mini bike build thread.

[RicksRides]

He needs to get another pulley for the input shaft (bottom). This thing is goin to be built for torque. Oughta be fun.

 

[MEASURE TWICE]

Jared came over today and we fabbed the tranny box. It is a belt drive 2 speed. Super Heavy Duty.

It looks like a torque converter you have. When you mention two speed is that you have a way while moving to switch to use different size pulleys engaging to have two different ratios. It is my understanding that the torque converter automatically switches the ratio. I guess an overall ratio could be changed and the torque converter would operate with difference low and high end speeds when different size pulleys were enacted.

MT

 

[RicksRides]

It looks like a torque converter you have. When you mention two speed is that you have a way while moving to switch to use different size pulleys engaging to have two different ratios. It is my understanding that the torque converter automatically switches the ratio. I guess an overall ratio could be changed and the torque converter would operate with difference low and high end speeds when different size pulleys were enacted.

MT

Yes the overall ratios are changed this is geared for 10mph in 1st and 20 in high. Yes it can be shifted on the move. We have to make the shifter assembly yet

 

[curtisfox]

That's going to be really Koool when done. Sort a like this old off road bike plan.
http://www.vintageprojects.com/mini-bike/mini-bike-plans.pdf
Only much better shift on the go.............Curt

 

[RicksRides]

Thanks for the link
Interesting mini bike

 

[curtisfox]

Thanks for the link
Interesting mini bike

Welcome!
Lots of old plans from the past.
http://www.vintageprojects.com/ Some neat ideas in here..........Curt

 

[jared8783]

Those mini bike plans link with the fat tire. That was one of the first things I came across when trying to figure out what exactly I was going to build. That inspired this alot, fat tire and what not.

And as for the gearing. I went with 10 and 20 mph because those are the first two gears on the rokon. I am thoroughly impressed with that bike. That is why I am using basically the same engine as the rokon. The rokons also have a third gear that goes up to 35-40 mph. And the rokons also have a cvt plus three gears to shift. They use drive shafts and gears but same concept.

What Rick and I are building I would somewhat consider this bike to be a cross between the vintage fat tire plans that were just posted, and the rokon.

Just thought I would throw that out there, that's where I derived most of my inspiration. That and I have seen two other minibike builds on youtube with same engine and tires as I will be using. If I remember I will post them later.

 

[curtisfox]

OK AWESOME
You are doing a great job on it,i am loveing it. I will be watching as you go,and can't wait to see your version when done...................Curt

 

[MEASURE TWICE]

I think I saw somewhere there was someone trying to work out a belt shift across pulleys. I think it ended with something like a outer and inner shaft that would switch two sets of pulleys. I'm not sure why a derailleur for a chain can't be also made for belt.

My 26 inch wheel drive I have a 3hp not with 22:1 ratio and I think it is max at about 10 mph. The prior 14:1 ratio was just to high a ratio to get up steep hills without a long run up but I think it was doing on the flat about 25mph.

MT

http://motorbicycling.com/showthread.php?p=530110#post530110

 

[jared8783]

Ill just leave this right here. Babe on a Rokon. Dang snow. We got tons of it today don't we Rick?

 

[curtisfox]

Like the Gum,double your pleasure,double your fun. And WOW

 

[RicksRides]

loads of snow here likely to get 12 more inches by morning, you to good to come over in a blizzard we re losing valuable build time.

 

[RicksRides]

We worked on it a bit today

 

[RicksRides]

4 more pics. This thing will have a little over 7 inches of ground clearance. Jared is in the last picture dreaming of a finished machine. Ive named it the "Not So Mini"