Stage 3 212cc clone speed.

[kart_goes_brrr]

It's flat, just streets.

There's some potholes if that matters idk. Do I need to consider some safety or something?

 

[bob58o]

Alright so:
1. From what I understood it's probably #35, I'll still verify tomorrow, just to be sure, how do I verify?
2. 20mm confirmed.
3. Diameter or like length? I think it's 1" bore I'm still not sure, as for the length it's probably over 70cm. I still need to verify every thing I'm still not 100% sure.

Another thing is, I'm tight on the budget as
mentioned before and now I'm having some problems with delivery since it's getting late for anything to arrive on time. My only option here is the item needs to arrive before 10 April and needs to be shipped to Saudi Arabia (a relative is travelling there soon). I can't order directly from my country because they can't ship since there's some type of system where you have to pay triple the price of the item to get it inside the country, if they even allow you

Diameter… so you could find a replacement sprocket hub if you needed to.

The 16T is probably only good if you want to shoot for that top speed we started with. For practical driving, you’ll want smaller tooth count

 

[kart_goes_brrr]

Go Kart Gear Ratio Speed Calculator

www.bmikarts.com

And get one of these.
View attachment 152194

Yeah I found a cheap identical one:

https://amzn.eu/d/6oxwOI0

My question is, is it really necessary? What's the purpose for it?

 

[kart_goes_brrr]

Diameter… so you could find a replacement sprocket hub if you needed to.

The 16T is probably only good if you want to shoot for that top speed we started with. For practical driving, you’ll want smaller tooth count

So from the options I have for the moment what's the best choice?

 

[kart_goes_brrr]

Let's say I want practical driving without the motor taking forever to get over 3000rpm for example. What are the stats for each option? Once again thanks for the massive help.

 

[Sparkwizard]

Count the teeth on your rear sprocket. Count the teeth on your clutch.
Divide the big number by the small number. The answer should be as close to 5 as possible.
Example: 60 tooth rear sprocket with a 12 tooth clutch.
60 divided by 12 is 5. That would be a 5:1 gear ratio.
This means your engine turns 5 times for every one turn of the rear wheel.
It reduces your axle speed by 5x but is MULTIPLIES your torque, or pulling power X5.

 

[bob58o]

Well if you are keeping the rear sprocket and it is #35 32T…

I’d probably get a 20mm 12T #35 clutch,
A Jackshaft kit with 5/8” shaft,
A 5/8” bore #35 24T sprocket to connect to the clutch,
And a 5/8” bore #35 14T sprocket to connect to the axle sprocket.

and enough #35 chain for both sets of sprockets.

 

[bob58o]

And if the other sprocket is #35, 45T and you want to use that, I’d probably get the same stuff but get an 18T jackshaft sprocket instead of the 24T (keeping all other stuff the same).

Both would give you a final reduction in the 4.6 : 1 to 4.8 : 1 range and should be ok for 11” tires. About 38 mph at 5400 RPM.

 

[JimD]

I guess we should verify, are we talking a go kart or a mini-bike? Since the discussion started under go kart discussion I made the assumption you are talking about a go kart.

I took a closer look at your picture with the chain on the axle sprocket. I think that sprocket on your axle is either a #428 sprocket or a #40 sprocket both of them are the same thickness .284. They are both a 1/2" pitch between the pins on the chains but roller is very large on a #428 chain. It is .335 in diameter. I think the chain you got with the clutch is either #41 or #420 same dimensions but the #420 is prestretched chain. So lets find out what you have for an axle sprocket before you start buying stuff you cannot use. Give us the axle diameter. If you don't have a caliper than borrow one. Give us the thickness of the rear sprocket. I already know the diameter of the rollers on the chain.

 

[Whitetrashrocker]

Yeah I found a cheap identical one:

https://amzn.eu/d/6oxwOI0

My question is, is it really necessary? What's the purpose for it?

Mostly to have a tachometer.

 

[kart_goes_brrr]

I guess we should verify, are we talking a go kart or a mini-bike? Since the discussion started under go kart discussion I made the assumption you are talking about a go kart.

I took a closer look at your picture with the chain on the axle sprocket. I think that sprocket on your axle is either a #428 sprocket or a #40 sprocket both of them are the same thickness .284. They are both a 1/2" pitch between the pins on the chains but roller is very large on a #428 chain. It is .335 in diameter. I think the chain you got with the clutch is either #41 or #420 same dimensions but the #420 is prestretched chain. So lets find out what you have for an axle sprocket before you start buying stuff you cannot use. Give us the axle diameter. If you don't have a caliper than borrow one. Give us the thickness of the rear sprocket. I already know the diameter of the rollers on the chain.

Go kart yeah. Should be 1" bore, still not sure tho, I'll check tmrw, rn it's 11 pm for me.

 

[kart_goes_brrr]

Count the teeth on your rear sprocket. Count the teeth on your clutch.
Divide the big number by the small number. The answer should be as close to 5 as possible.
Example: 60 tooth rear sprocket with a 12 tooth clutch.
60 divided by 12 is 5. That would be a 5:1 gear ratio.
This means your engine turns 5 times for every one turn of the rear wheel.
It reduces your axle speed by 5x but is MULTIPLIES your torque, or pulling power X5.

I calculated that if I use a 10T clutch and a 45T sprocket, I would get the ratio of 4.5,which is pretty good right?

 

[kart_goes_brrr]

Maybe I could find a 50T sprocket too

 

[bob58o]

If using 1/2” pitch rear sprocket, then yes you could probably use a 1/2” pitch 10T clutch and you’d be ok with a 45 or 50T sprocket. You wouldn’t need a jackshaft.

If using 3/8” pitch, then I believe the smallest sprocket You’ll find on a 20mm bore clutch is 12T. With a #35 12T clutch, you’d want around #35 54T - 60T in the rear.

Just be aware that the bigger the rear sprocket, the less ground clearance you will have.

An 8” rear sprocket with 11” tires only leaves about 1.5” of clearance. So nothing bigger than 50T in 1/2” pitch… And nothing bigger than like 66T in 3/8” pitch.

 

[kart_goes_brrr]

If using 1/2” pitch rear sprocket, then yes you could probably use a 1/2” pitch 10T clutch and you’d be ok with a 45 or 50T sprocket. You wouldn’t need a jackshaft.

If using 3/8” pitch, then I believe the smallest sprocket You’ll find on a 20mm bore clutch is 12T. With a #35 12T clutch, you’d want around #35 54T - 60T in the rear.

Just be aware that the bigger the rear sprocket, the less ground clearance you will have.

An 8” rear sprocket with 11” tires only leaves about 1.5” of clearance. So nothing bigger than 50T in 1/2” pitch… And nothing bigger than like 66T in 3/8” pitch.

Alright, we're getting there finally, im gonna check the options and we'll see. Thanks.

 

[kart_goes_brrr]

So you were right about the clutch sizes, there's only 12T in 3/8" pitch, now I'll check with the seller if he has any sprocket in stock. What's the minimum teeth? You said 66T maximum for 3/8" pitch.

 

[JimD]

Slow down you are doing too many things at once and I cannot figure if you are going up-hill or down-hill. Are you going to use the axle in your picture 100 pages back that the chain isn't going on that you got with the clutch?? The chain is NOT fitting the sprocket on the axle because the chain is not wide enough because it is #420 chain and the sprocket on the axle is either #40 or it is #428. All I am trying to do for your friend bringing you the parts is so he doesn't need a container to carry everything you need because nothing is going to fit unless you slow down and do one thing at a time. END OF STORY.

 

[kart_goes_brrr]

Slow down you are doing too many things at once and I cannot figure if you are going up-hill or down-hill. Are you going to use the axle in your picture 100 pages back that the chain isn't going on that you got with the clutch?? The chain is NOT fitting the sprocket on the axle because the chain is not wide enough because it is #420 chain and the sprocket on the axle is either #40 or it is #428. All I am trying to do for your friend bringing you the parts is so he doesn't need a container to carry everything you need because nothing is going to fit unless you slow down and do one thing at a time. END OF STORY.

Yes I'm using the axle,tryna figure out the pitch. thanks.

 

[Sparkwizard]

Thanks for stating that, @JimD

 

[Sparkwizard]

Measure from the bottom of one of the teeth to the bottom of the next tooth with a tool that measures in inches.
If it measures 1/2 inch, that equals 4/8ths.