Front track, rear track and wheel base

[Jim-L-L]

Hey, I've noticed lot's of short wheel base buggies and racing go karts have a wider rear wheel track than front ? is this to improve turning circle and handling with a live rear axle ? read elsewhere that narrowing the rear can also improve cornering as well, would be keen to hear any thoughts on the subject ? Are there any golden rules on wheel track ?

 

[2SlickNick]

My 150cc buggy is short wheelbase, wider in front than rear with a good turning radias for the trails.

 

[firemanjim]

I think they make the fronts wider, so it's less prone to flipping over.

 

[OzFab]

You know, I was leaning towards the opposite, narrow rear for improved steering capabilities but, has a tendency to flip; wide rear end needs improved steering components & is harder to flip at speed...

Shorter wheelbase also improves steering capabilities

 

[tazmannusa]

There is a lot to it on racing chassis, I use to run a offset chassis on dirt oval tracks, adjustable hubs on rear axle,Left side in and right side out , right front spaced out with wider tire, left front spindle spaced downward a little to transfer a little more weight to the right rear, 6 lbs left 8 right. All settings varied to the track you run on that day.
For a play kart I don't think there is a golden rule, tires and weight make a huge difference . My play kart that I just finished was setup for a 6 to 8 hp I moved the axle back 5" from what was in the plans and ran 18" superturf tires, front end setup with a good caster camber angle and it handled and turned quick. Now that I upgraded to the 13 hp and put on 20" knobby's it don't turn , to much traction but it sure rides smooth.
Axle should be a couple more inches back and engine couple inches forward witch would put the seat a couple inches forward

 

[Russell ATV]

Much depends on the purpose of the kart. Nothing can turn with more g force than a racing kart. They can pull 2Gs in a turn. They are almost square in terms of their dimensions (43"), except the rear wheels can push out to 50". For sand, you want something longer. For off road trails, you want it narrow enough (48" or less) to fit the ATV tracks.

Most of the time, the mechanical bits dictate the location of axles and wheels. Need to put a person in the kart, an engine, and wheels. The bigger it is, the more it will weigh, so you want it as compact as possible. Center of gravity and proper front wheel arrangement is the most important things to consider.

Russ

 

[Jim-L-L]

Thanks guys, really good info, the reason for the question was that I'm thinking about my next project which would be a 2 seater sand rail type buggy

dimensions would be
Wheel Base = 2286mm =7-1/2'
Wheel track R =1430mm =4-3/4'
Wheel track F = 1300mm = 4-1/4

The wheel track dimensions all come from existing components, and I don't want to make the wheel base any shorter, due to me being tall,

I think I read once that a good buggy wheel track should be 2/3 of wheel base, which for my project would be a 5' wheel track, I can make the front wheel track wider to match the rear,
Any thoughts

P.s going outside to sketch it out with kid's chalk : )

 

[OzFab]

Wow, that's long, your steering is gonna suck...

Using a 2:3 ratio, the difference is around 100mm (4"); using a 3:4 ratio, the difference is closer to 300mm (12")...

I realise you want to keep the length due to your height but, is there any way you can shorten the wheelbase? It doesn't mean you have to shorten the frame, simply move the axles...

 

[Jim-L-L]

Wow, that's long, your steering is gonna suck...

Not if I'm using excess HP to oversteer the corners

Using a 2:3 ratio, the difference is around 100mm (4"); using a 3:4 ratio, the difference is closer to 300mm (12")...

4" I can probably get away with

I realise you want to keep the length due to your height but, is there any way you can shorten the wheelbase? It doesn't mean you have to shorten the frame, simply move the axles...

Nah not really going wider is the only option