Help needed, Thanks you

[John Eli Bowman]

I am trying to build a gocart for my son Jr and never done this before. I bought a used frame with 22 inch tires and a 64 tooth axle sprocket and was missing everything else. I bought a used 5 horse Briggs and Stratton engine and found out that I had to get rid of the direct drive and going with a double sprocket set up. I bought a new 10 tooth clutch and a double sprocket set up for the drive. I guess I am asking you guys, we have a 10 tooth clutch to a 40 tooth sprocket and a ten tooth sprocket to the 64 tooth sprocket axle, will this work ? The 40 tooth sprocket and ten tooth sprocket are one set and turn together. I can't get a pic to load up either!

 

[anickode]

You're going to have a 25.4:1 gear ratio using that double reduction.

With 22" tyres, you will have a top speed of 9mph. Granted, it would be an absolute stump puller, but 9mph ain't much fun.

When running multiple stages of gear reduction, the ratios multiply.

 

[Hellion]

...to the forum, stranger.

One thing that sticks out at me is the enormous tires. Everything else is supposed to be smaller in this hobby, usually.

I'd get some smaller wheels/tires just for the cost savings as smaller is cheaper.

Where do you and your son intend to undertake this newfound go karting hobby? Pavement, off road (mud, dirt, sand, etc), or...?

To post photos, you have to use the "Go Advanced" or "Post Reply" button, either of which will take you to the advanced posting/reply area. There you will see the Manage Attachments button which you use to upload your photos from your machine.

 

[Bbqjoe]

Pay no attention to Hellion.
He missed the Photobucket memo.

 

[Hellion]

I sure did. Care to bring me up to speed?

 

[Bbqjoe]

I sure did. Care to bring me up to speed?

Yeah, they changed the horse in the middle of the race.

If you want to use them as a third party host (Like posting pics here)
You have to now pay about $400 yr.

I'm using Imgur for now, until they get upset.

 

[David Ham]

Yeah, they changed the horse in the middle of the race.

If you want to use them as a third party host (Like posting pics here)
You have to now pay about $400 yr.

I'm using Imgur for now, until they get upset.

this is what we see

 

[Bbqjoe]

 

[Hellion]

Hijack, this is a hijack!

Oh, that memo. I see it now, just needed a refresh I guess.

Fixed. All glittery and purple like Joe likes.

 

[Functional Artist]

Yeah, they changed the horse in the middle of the race.

If you want to use them as a third party host (Like posting pics here)
You have to now pay about $400 yr.

I'm using Imgur for now, until they get upset.

I didn't get any memo

musta been busy makin' somethin'

...are youse guys seein' my photos?


Back to topic

Mr Bowman,

Are you measuring, your tires, from the ground to top of the tire?

...or measuring all the way around?


Hellion is right,

sounds kinda big for a kart

 

[Bbqjoe]

Mr Bowman,

Are you measuring, your tires, from the ground to top of the tire?

...or measuring all the way around?


Hellion is right,

sounds kinda big for a kart

This is why we need pics!!!!

 

[bob58o]

So lets say the average kart is geared 5.4:1 with 13" tires (6.5" radius) with 5-6.5HP engine.

You've got 22's (11" radius).

11/6.5 = 1.69
1.69 x 5.4 = 9.14

Ignoring weight and other non trivial things...
A kart with 13" tires geared 5.4 : 1 should be similar to a kart with 22" tires geared ~9:1

Now lets say this big kart with big tires weighs 400lbs with driver, compared to smaller kart that would be less than 300lb with driver.

400/300 = 1.33
9 x 1.33 = 12

I'd use 12:1 as a starting point for gearing.
It would do around 20 mph at 3600 RPM.

That's how I do quick and dirty gear ratio approximations when there aren't pictures. LOL

---------- Post added at 12:27 AM ---------- Previous post was at 12:21 AM ----------

So swap out the 40T sprocket for something in the 17 tooth - 20 tooth range. Unless it weighs a ton, then keep the 40T and enjoy 9mph at 3600 RPM.

I'm Imagining a Smart car on 22's powered by a snow blower.

 

[landuse]

I bet you that is a South African pic. I see those often enough on our roads