Frame design

[Bansil]

I remember seeing that junk years ago at the grand rod run in pigeon forge, looked great BUT if jb weld is syronger

 

[Millwright]

Possible or not, I want it removable.

 

[Bansil]

Millwright, that was more a joke , sticky foam should keep rattles down

 

[Millwright]

Lol. Ya I get ya.

 

[madprofessor]

Agreement on removeable, necessary or not. Never know, might want to change some things in the future.

 

[Millwright]

A little more progress.
Not sure what's up with the colour. It was supposed to be gloss white.

 

[Bansil]

Looks great! Very futuristic formula 1

 

[Millwright]

A little more assembly.
Still need to work out brakes and throttle.
Have a couple issues with TC to sort out.

 

[Bansil]

Almost...or actually does bring back memories of speed racer....

 

[Millwright]

Lol. Your age is showing.
Early 70's I think ? I loved it!!

 

[Functional Artist]

Nice work!

Looks super "heavy" duty (what do you think it weighs?)
...& ya could probably push a semi-truck with that front bumper

 

[Millwright]

I'm thinking 200lbs.
For sure 90lbs in tubing.
420cc engine must be 60lbs?
Wheels and misc. parts?

 

[Snaker]

Take a look at this: 1969 Polaris Star go cart
Warning, after one minute, its all ads.

1969 Polaris Star Car Go Cart - Jason Gibbs Polaris Star Car Go Kart - YouTube

 

[Bansil]

Born 68 so between speed racer, Gilligan's Island, land of the lost, I dream of genie and others....gosh where do you stop?

 

[madprofessor]

That 420 is going to put 76 lbs. on it. Should be a wheelie beast.

 

[Millwright]

Well my belt has finally arrived.
Throttle linkage and brakes still need to be completed, and then I'm good to go!!
I have an assortment of sprockets to play around with.
10, 13, 18, 36, 45, 54, and 60.

Kart weight with me should be about 425 lbs.
Wheel size is 16"
Engine is box stock 420cc
40 series torque converter.

I'm looking for reasonable torque to get going, but more interested in top end speed.

I'm guessing the 13,T with the 54T might be my best combination.

 

[madprofessor]

That's a 4.15:1 final ratio with the 54:13, but be sure. If you find you need more low end torque, you may find you need a larger axle sprocket than there is available reasonable ground clearance for it.
Starting with a 10T on the CVT will allow you to use smaller sprockets on the axle, and that can be as small as you dare go to load top end.
Conversely you could fit a real torquey larger axle sprocket without chewing it into the sand. Think wood baseball bat into a meat grinder.

 

[Millwright]

That's a 4.15:1 final ratio with the 54:13, but be sure. If you find you need more low end torque, you may find you need a larger axle sprocket than there is available reasonable ground clearance for it.
Starting with a 10T on the CVT will allow you to use smaller sprockets on the axle, and that can be as small as you dare go to load top end.
Conversely you could fit a real torquey larger axle sprocket without chewing it into the sand. Think wood baseball bat into a meat grinder.

Well I'm thinking I'm going to have enough HP to always reach the 3600 RPM, so I'm guessing I might get into using the 18T on the driver.
Anyways, that's why I picked up a range of sprockets. I'll play around with the ratios, see how high, and how low I can go and still have a functional kart. I'll be running on a flat paved rural road so I'm not too worried about the rear sprocket grinding in the sand.
I'm pretty certain I'm going to start of with the 6:1 ratio, and then increase the tooth count on the drive hub.

 

[madprofessor]

I'm a cheapskate and sometimes lazy. I'd go the other way, starting with the biggest sprocket I might want to use and shrinking down from there.
Why? Because each sprocket change downward would mean removing a chain link(s) instead of having to add little bits to the chain.
No extra master links and half links to buy to make up the chain.
And on that rigid kart I'd most definitely make a rigid idler gear chain tensioner and lock it down. Spring-loaded ones are for suspensions.
Pic attached of chain drive to pitman arm with a spring-loaded tensioner made into a rigid one, using the cheap nylon roller that was on it. Other pic is secondary drive chain with an idler gear that gets adjusted up/down for tension and then locked down.

 

[Millwright]

Hmmmmm. Good point on the chain link issue.