Tire and Rim question for noob

[utahoutdoors]

So we getting our part list together on what we need and take
it in design consideration.

Building 2 seater with a 301cc or 420cc enginee.

From what I read general speaking I want to think about a front tire 12" in size and 15" for the rear.

Front: I thinking of a 6 inch rim with a 3.5" or 4" wide tire. Rounding knobby style tire.

Rear using 6" hubs as well but a 15" tire with a 7 or 8 wide more flat tire.

Such as this http://www.bmikarts.com/15-x-600-6-Turf-Tire-_p_1533.html

Any suggestions or ideas?

 

[crazykart]

Yup, those are tires.

Any specific questions you have?

 

[utahoutdoors]

When looking at hubs or wheels am I better off with 5 vs 6" hubs.

Is there advantages/disadvantages having wider tires on front?

For turning reason I would thing a rounded style knobby would be best on the front.

Any good online resources for buying both?

 

[Poboy kartman]

6" tires and rims are more common....therefore, offer more choices and more opportunities to price shop.

 

[crazykart]

Get the hubs made for the rims, hubs for 5" rims are just for that 5" rims.

I would think you would want as much contact surface with the ground as possinke in the front while turning, so I would go with ribbed slicks unless going off road. As for wide vs. Skinny in front they both have their merits so its more of personal choice imo.

Mfgsupply is a good one because their shipping is a flat rate no matter how much you get, but there are plenty of other places.

Now, here's a few good questions for you:

Will this be on road or off road?
Thats a fairly powerful engine, do you know what your gearing will be yet?

 

[utahoutdoors]

It will be almost 90% off roads. Living hear in the high desert to the west and the high mountains (over 11,000ft) to the East. We spend a lot of time out in these great out door play grounds. We plan on going with the bigger engine because want to give the torque for the many BLM roads we plan on traveling on. Have not figured out the gearing as yet.

 

[crazykart]

For off road like that I'm going to suggest bigger tires. Not only for better grip, but fir better ground clearance as well. I would say you probably want to keep your tire sizes front and back relativly close.to each other as well.

You'll have enough hp.

Imo Id say 18" tires both front and rear, or push the rear to 20" front to 18" (cheap rims for said tires: http://recstuff.com/8-inch-trailer-wheels-4-bolt.aspx )

Idk what engine exactly you're using (would be helpful to know) but if possible get a torque converter.

Gearing, with 20" tires, a TC, and rocky/hilly and or sandy terrain I personally would be leaning towards around a 10:1 ratio. With 18" tires instead you may be able to go down to an 8:1 ratio.

Others will chime in, but this is what I would personally do in the same situation.

If you dont have an engine yet, and are still thinking about which to get... I'd try to find a snowmobile engine that has the driver and driven pully. Might possibly find it cheap, especially compared to the possible price of a 40 series TC and big engine.

 

[landuse]

For off road like that I'm going to suggest bigger tires. Not only for better grip, but fir better ground clearance as well. I would say you probably want to keep your tire sizes front and back relativly close.to each other as well.

You'll have enough hp.

Imo Id say 18" tires both front and rear, or push the rear to 20" front to 18" (cheap rims for said tires: http://recstuff.com/8-inch-trailer-wheels-4-bolt.aspx )

Idk what engine exactly you're using (would be helpful to know) but if possible get a torque converter.

Gearing, with 20" tires, a TC, and rocky/hilly and or sandy terrain I personally would be leaning towards around a 10:1 ratio. With 18" tires instead you may be able to go down to an 8:1 ratio.

Others will chime in, but this is what I would personally do in the same situation.

If you dont have an engine yet, and are still thinking about which to get... I'd try to find a snowmobile engine that has the driver and driven pully. Might possibly find it cheap, especially compared to the possible price of a 40 series TC and big engine.

Well said...

 

[utahoutdoors]

For off road like that I'm going to suggest bigger tires. Not only for better grip, but fir better ground clearance as well. I would say you probably want to keep your tire sizes front and back relativly close.to each other as well.

You'll have enough hp.

Imo Id say 18" tires both front and rear, or push the rear to 20" front to 18" (cheap rims for said tires: http://recstuff.com/8-inch-trailer-wheels-4-bolt.aspx )

Idk what engine exactly you're using (would be helpful to know) but if possible get a torque converter.

Gearing, with 20" tires, a TC, and rocky/hilly and or sandy terrain I personally would be leaning towards around a 10:1 ratio. With 18" tires instead you may be able to go down to an 8:1 ratio.

Others will chime in, but this is what I would personally do in the same situation.

If you dont have an engine yet, and are still thinking about which to get... I'd try to find a snowmobile engine that has the driver and driven pully. Might possibly find it cheap, especially compared to the possible price of a 40 series TC and big engine.

OK you got me thinking as I was welding tonight with the the back area I plan on putting the 301cc predator engine.

I did some more research, then some more.... So can you help me understand a little more on the difference betwen a torque converter and Jack Shaft. When do I need to take it from the torque converter to a jack shaft then to the axel. VS just going from engine to a torque converter to the axle?

Thanks for your assistance.

 

[crazykart]

A jackshaft is usually used in compound gearing to achieve better gear ratios when you can't fit a bigger sprocket (for instance) onto the back axle or etc.

Think of a TC as an automatic transmission in a sort of ways. Depending in the rpms of the engine the TC will shift from high torque/low speed to low torque/high speed. Instead of one fixed gear ratio it gives you a range of gear ratios, but it is still dependent on the axle sprocket size, and the driven sprocket size.

With a TC you still need a "jackshaft" but it's the driven that's mounted as the jackshaft.

The set ups go like this:

Non tc: clutch to input gear on jackshaft, output gear on jackshaft to axle sprocket= one fixed gear ratio

Tc: driver to driven (mounted to jackshaft), driven to axle sprocket = a wide ranger of gear ratios that the tc automatically shifts through depending upon the need.

Does that better help you understand the setups, or do you have any more questions?

 

[OzFab]

A jack shaft is still fixed gearing; no matter what else is happening, the gear ratio will always remain the same...

A torque converter is a pair of variable clutches which work together to vary the drive ratio, depending on the speed of the vehicle & the RPM of the engine...

If you're asking "is one better than the other" the answer is HECK YES! A torque converter will beat fixed gearing every time...

 

[utahoutdoors]

So with a 301cc it has a 1" shaft. If I use a TC such as this.

http://www.bmikarts.com/Torque-Converter-for-35-Chain-1-Bore-TAV2-Replacement_p_2527.html

Which comes with comes with a 12 tooth on the one side of the TC. With a 60 or 72 count tooth I can go to my axle direct... Correct?

Or do I need one more step by going from the 12 tooth to a small jack shaft. Which goes from the JS to the axle. Is this needed to give you additional torque and gearing?

Why not just go from the TC to the axle?

With a 301cc engine 8HP is the TAV2 a good match. But if I go with a 420cc 13HP is this TAV2 a match or is this motor a over kill.

Thanks again.

 

[crazykart]

Well first off, don't get that particular lit as it uses a #35 chain and that will be too weak for your application. Find one that uses a 40,41,420 setup, and I do believe you can find it with a 9 or 10 tooth output on the driven. With a 9 or 10 on the driven I'd go with at minimum a 72 tooth on the axle, if not an 80+

Edit: a 8hp engine is at the top end of what a 30 series can handle, a 1 3hp is way too much, would need a 40 series, which is very expensive in comparison

 

[utahoutdoors]

Well first off, don't get that particular lit as it uses a #35 chain and that will be too weak for your application. Find one that uses a 40,41,420 setup, and I do believe you can find it with a 9 or 10 tooth output on the driven. With a 9 or 10 on the driven I'd go with at minimum a 72 tooth on the axle, if not an 80+

Edit: a 8hp engine is at the top end of what a 30 series can handle, a 1 3hp is way too much, would need a 40 series, which is very expensive in comparison

What to you mean with the 40,41,420 setup? The "driven" is the part of the TC which has the gear?

Edit: I think the 40,41, 42 is the teeth in the TC.

Such as this....

http://www.amazon.com/gp/product/B0..._m=ATVPDKIKX0DER&pf_rd_r=0E2T9C63J7BWRXZQCXQA

 

[landuse]

You will need a 40 series TC with the engine you have. There are cheaper versions of it for sale on ebay that are not badly priced

 

[utahoutdoors]

So the 30 series TC is on the edge of the 8HP with a 301cc. I assume the 40 series
is more robust and better to handle the bigger engine ??

So is a 420CC 13HP are big over kill on a go-kart (off road), 2 seater, with 14 - 18 tires?

I think the 301cc is will plenty in size to provide 2 adults the power and necessary speed
for such a kart.

 

[landuse]

Yes, the 40 series is the more robust option to go for.

What to you mean with the 40,41,420 setup? The "driven" is the part of the TC which has the gear?

Edit: I think the 40,41, 42 is the teeth in the TC.

No, it means the size of the chain and sprocket. You get #35, #41, and #40 (amongst others). Google it and you will see that the teeth for each type are spaced differently from each other. #35 is the weaker of the three. The 40 and 41 chains are more robust and are used for more powerful engines

 

[utahoutdoors]

Thanks landuse.... Becoming more clear now...

 

[crazykart]

With 18" tires, the proper gearing, and a tc an 8hp should push you around just fine.

Don't expect a great deal of speed though, but for your application a great deal of speed isn't needed.

A 40 series would suit you better (stronger, more robust) and wouldn't wear out as fast, but a 40 series would depend on your budget. If you can afford a 40 series then don't cheap out, get one!

Yes as stated #35,40,41,420,etc is the chain pitch and size, with 35 being the weakest, and more like a bike chain. A 35 would possibly snap under a load like that.

For the terrain you're going to want to gear as much towards torque as possible, you don't want to not be able to make it up a hill lol.

 

[utahoutdoors]

With 18" tires, the proper gearing, and a tc an 8hp should push you around just fine.

Don't expect a great deal of speed though, but for your application a great deal of speed isn't needed.

A 40 series would suit you better (stronger, more robust) and wouldn't wear out as fast, but a 40 series would depend on your budget. If you can afford a 40 series then don't cheap out, get one!

Yes as stated #35,40,41,420,etc is the chain pitch and size, with 35 being the weakest, and more like a bike chain. A 35 would possibly snap under a load like that.

For the terrain you're going to want to gear as much towards torque as possible, you don't want to not be able to make it up a hill lol.

Thanks Crazykart,

Budget is not big, but not so tight not to get the correct parts. I just plan for it a few weeks out. I did noticed only a few
40 "complete kits" vs 30. Most of the parts for to 40 were in
non-kits, I will need to search some more.

I made some great progression on the frame this week just waiting now for Friday parts to arrive from 2 vendors. So it will
start to come together and start to look like a kart vs a pile of
steel in the garage.