Shifter kart resources

This is totally not a critical question.  I'm daydreaming...  but it's evening.  Duskdreaming?  I have this illness where everything I see becomes something that can be powered with an engine and used for fun purposes.  This time, it's the dolly/frame part of a hospital bed.  It's pretty beefy 2x3 square tube and it just makes me think it's begging for a 600cc motorcycle engine and tires that are wider than they are tall.

So I have experience racing a go-kart and I have experience racing a car.  When I say go-kart, I mean the ubiquitous 5hp tube frame things beside mini golf.  I have no experience with things that fall in between a car and a go kart.

I'm curious where you go from a solid axle and a sprocket to something with a differential, and at what point do you add an actual suspension instead of just letting the chassis flex?  Anyone know of a book or website that might get me started?

But I mean, look at this thing.  Doesn't it scream "make me a go-kart"?

A 125cc shifter kart powered by a MX bike motor with a 6-speed is so quick that it's difficult to explain.

Take a look. https://youtu.be/C6rXSjpdLz0?si=IpgRI9lleWELZiAN

lotusseven7 (Forum Supporter) said:

A 125cc shifter kart powered by a MX bike motor with a 6-speed is so quick that it's difficult to explain.

Take a look. https://youtu.be/C6rXSjpdLz0?si=IpgRI9lleWELZiAN

Curtis73,

Somehow, score a ride in a 125cc shifter kart.  I dare you to say it's not fast enough for you.  I mean, some people think they are too slow; that's why there are 250cc superkarts.  But not very many people...  :-)

First thing is to not to call a racing kart a go-kart. You will offend the person with the racing kart. The difference between the fun 5 hp go-kart a racing kart is huge. Just like the difference between a Corolla and a GTP car.

I used to race a 125 cc shifter kart, and they are serious tools. It wasn't really that much fun to race because it beat the crap out of me. After my first race, I took up an exercise regime that included lots of neck exercises, because by the 4th lap of a 6 lap heat race I couldn't hold my head up in the turns anymore. When I got the shifter kart I wondered why there was a "masters" class for drivers over 40 years old, but after one race I understood! It typically took around three days after a race to not hurt everywhere in my body; racing one is like sitting in a paint mixer that generates 2 G of cornering force in an instant.

When they were fun to race was in the rain, because you went slow enough to not pull your head off your neck or break your ribs. Plus you could drift the thing around the turns and carry the tail-out attitude all the way down the straight if you wanted to. I learned to put my chin down to my chest in tight turns, because the front tires generated enough fire-hose water spray that in a tight turn the water blast would hit you square in the chest and funnel right up into the helmet and soak your face.

The thing is, a real racing kart is designed to go quickly (turn, brake, accelerate) in an easily controlled manner. Putting an engine on a shopping cart or something like that will only create a device that is going to try and kill you.

That looks like a lower version of the lawnmower-engine-powered bar stools, which are scary fast because they're not meant to exist.

More to the point, I don't think there's a continuum where you add suspension and a point where you add a diff... A car and a kart are just different vehicles.

You could build a car-sized kart, I guess, and you could build a tiny car, but in both cases the whole package has to be made to work like a kart OR work like a car.

The central thing is that something with no diff has to find a different way to corner. Karts do this by a combination of geometry and chassis construction that effectively lets you unweight the inside rear while you're getting it turned. The crazy offset between kingpin and wheel isn't accidental, nor is the caster. They turn into tricycles as you steer, pulling the outside front wheel up and shoving the inside front wheel down, lifting  the inside rear off the track. I'm pretty sure that long axle with no diff is how something so short can be relatively stable; once both rear wheels are on the ground, it wants to go straight.

To be sure, no expert me, but I've done a bit of reading. I just had a skim of my copy  of The Karting Manual and I don't think I'd recommend it for a foundation. It skims over what you can tune and for what effect, but doesn't really go into why. Wish I had a better suggestion or links, but searching up "how karts work" with an eye toward how fundamentally different they are from cars is the central thing. I did try to do better, but I mostly got driving tips, and I also got one hit where at least one party insists that it's not about the front-end geometry and all the wheel lift is accommodated with flex and load. I'm dubious, but like I said, I'm not an expert.

IMHO, it looks like a  pile of tubes that wants to invite you into a terrible project. I'd go buy a Biturbo or a boat. If you want to scratch build a kart or a buggy, that handful of tubes and welds isn't saving you enough work to let it do your foundational design.

Looks like a perfect based for electric golf cart hospital bed hybrid. 

Add the golf cart driveline and suspension underneath and keep the adjustable bed with rails up top. 

I did not have 'hospital bed based death kart' on today's bingo card - you win the internet for today!

I did have a thought that it would make a good DIY workstand for a bike though.

In reply to Curtis73 (Forum Supporter) :

I think I see your future.