School Project- Power Wheels Go-kart

[Bobby]

Hey everyone,
A group of friends and I are building a power wheels go kart. For some of who have heard of it, it is for the power racing series held at the World Maker Faire Link here.
So I have a couple of questions to ask regarding electric motors and gearing.
First off, the motors must be within 12-36vdc. I was thinking this motor would be a good choice: Motor.
Secondly, for the gearing, we were thinking of using 2 bicycle cassettes, these. One on the motor shaft and the other on the axle. However, I think that the lowest gear we could go with for the cassettes would be 3.4:1. That seems high but I'm not sure. The cart would weigh about 300-330LBS, including rider.
Lastly, what size tires should we run? We were thinking ~20" turf tires. Would they be too big?
Thanks in advance,
Bobby

 

[Bobby]

Hey everyone,
so we're changing the size of the tires to 10". This would help with acceleration, right?

Thanks.

and really? 75 views and no responses.

 

[ML-TOYS]

This will be a big help for you. Some of these guys are nuts
http://forum.modifiedpowerwheels.com

 

[Bobby]

Thanks ML-TOYS for responding. I'll start reading that forum tomorrow. What do you think about my gear ratio? Do you think I need to lower it or will it work because it is an electric motor?

 

[6StringMercenary]

This will be a big help for you. Some of these guys are nuts
http://forum.modifiedpowerwheels.com

Good advice, and I've heard mention that there's an active group on Facebook as well. Forum great for search / research (ex: gear ratios). I haven't checked out the Facebook side of it, but it might be good for you.

 

[ML-TOYS]

I suck at gear ratios. The power wheels forum i linked has very knowledgable people who modify. When i had my parts and reapir business i was a sponsor on there.

 

[drm]

Hey everyone,
so we're changing the size of the tires to 10". This would help with acceleration, right?

Thanks.

and really? 75 views and no responses.

Honestly, this is a diy forum and you want answers to questions that you should be trying to figure out or at least tell why you chose certain items.

Did you build the kart in your sig? I would think the bike gears would be trashed by the motor. With a proper controller you would not need at tranny...

 

[Bobby]

Drm,
I figured out what the ratios would be but i wanted a second, more expert, opnion on if they would work well for what we're doing. I think they'll be fine.

No, i haven't had the time or money to build the kart in my sig. The only reason we're building this power wheels is because it is a school project that has a due date. And for the money side of it, we have 5 people including that can split the cost.