New member...atc conversion mini bike.

[Chubby]

Hi folks, I'm new to this forum. I'm close to completing a project I've been wanting to do for many years. It's converting an atc to a two wheel mini bike. It's a great challenge and a learning curve. My biggest challenge now is fine tuning the gear ratio using a jack shaft. Ground zero was 10-14/14-49 a 4.9:1 ratio, and was extremely underpowered. Tried 10-20/14-49 a 7:1 ratio is much better but still underpowered. Next attempt I'm planning 10-30/14-49 a 10:1 ratio. Wish me luck.....

 

[OND]

Chubby....welcome aboard ! :thumbsup: Bike looks good...and I bet it rides good to.

 

[Tom S.]

8hp. Nice! Welcome. This is a great site.

 

[Brooklyn Bob]

Welcome to the minibike madness!

 

[chipper]

Nice build and welcome !!

 

[Chubby]

Gear ratio update...

Did a little more today.. Tried a new ratio, 10-35/14-49 give about 12:1 ratio. Much better! I'm not looking for big speed anyway. This ratio doesn't seem so hard on the clutch.

 

[spencertrax]

Cool, reminds me of one my brother (bigrob)did a few years ago. He may have some pictures.

 

[control4userguy]

Certainly, anything that large is not going to benefit from 6:1 ratio. On paper, a 9:1 would have been a good starting point...

What's the donor ATC? Looks like Honda, early 80s.

 

[Chubby]

Yeah it was an 83' Honda 200 atc. I'll be building another but will keep the atc engine this time. I've never built a mini bike before and gear ratios was my hurdle. I looked to these forums for gear ratio help and you guys were a great help, well appreciated. In my learning curve, time size is another issue effecting the end ratio. I'm still going to play with these ratios again. I'm thinking 13:1 or even 14:1 may be the happy spot.
Thanks for the help....

 

[Chubby]

Still making progress with new paint. Time to re-assemble.

 

[Chubby]

Now complete, I introduce to you "Fatty".