Technical Rear end

[smurth1984]

Hi all.
Im after a bit of advice and help on how to improve the rear end grip in my sons kart.
He has a synergy kart with a gx160 engine.
9yrs old, slim build, 5stone in weight.
The kart is set up on the lowest rear bearing holes in the chassis with the rear wheels out as far as possible.
Front end is slightly toe in with a 5mm wheel spacer.
Dunlop tyres are around 30 laps old and run about 18psi atm.
Rear bumper is metal and tight all side pods are loose.
Any advice will help as he keeps spinning out or drifting round corners when he is chasing another kart of similar speed.
Thanks

 

[Wolemid]

Hi all.
Im after a bit of advice and help on how to improve the rear end grip in my sons kart.
He has a synergy kart with a gx160 engine.
9yrs old, slim build, 5stone in weight.
The kart is set up on the lowest rear bearing holes in the chassis with the rear wheels out as far as possible.
Front end is slightly toe in with a 5mm wheel spacer.
Dunlop tyres are around 30 laps old and run about 18psi atm.
Rear bumper is metal and tight all side pods are loose.
Any advice will help as he keeps spinning out or drifting round corners when he is chasing another kart of similar speed.
Thanks

Tyre pressures should be around 24/26psi
Top holes on rear bearing hanger
Plastic rear bumper or Metal loose
Rear track width is -10mm either end
Front 5mm on outside of wheel.
You want 5 toe out, you never ever run toe in

(This is what we run my sons Synergy on in Honda in the dry)

Also if you email synergy they have a setup guide than can email to you which is very helpful

 

[smurth1984]

Tyre pressures should be around 24/26psi
Top holes on rear bearing hanger
Plastic rear bumper or Metal loose
Rear track width is -10mm either end
Front 5mm on outside of wheel.
You want 5 toe out, you never ever run toe in

(This is what we run my sons Synergy on in Honda in the dry)

Also if you email synergy they have a setup guide than can email to you which is very helpful

I thought the top holes was for less grip

 

[smurth1984]

I thought the top holes was for less grip

 

[Wolemid]

I thought the top holes was for less grip

Top holes lower the chassis which generate tyre grip.

Bottom holes raise the chassis which generates mechanical grip. Via changing the pivot point (hence why you go high chassis in the wet)

 

[smurth1984]

Top holes lower the chassis which generate tyre grip.

Bottom holes raise the chassis which generates mechanical grip. Via changing the pivot point (hence why you go high chassis in the wet)

Thanks for your reply’s and help.
So i want to put the bearing carrier bolts as high as they will go on the bearing holes in the chassis.
As there away of toe out 5mm with out lazers.
Sorry new to the sport

 

[smurth1984]

Top holes lower the chassis which generate tyre grip.

Bottom holes raise the chassis which generates mechanical grip. Via changing the pivot point (hence why you go high chassis in the wet)

Any chance you could send me a picture of the back and the front wheel setup
07712886998 wattsapp

 

[Seanl]

If you sign up on the website (it's free) you can go to the members area where there guides are published

 

[Wolemid]

Thanks for your reply’s and help.
So i want to put the bearing carrier bolts as high as they will go on the bearing holes in the chassis.
As there away of toe out 5mm with out lazers.
Sorry new to the sport

A crude way of doing it. Is lock your steering in place somehow. Tap measure inside back of front left wheel rim to inside back of front right wheel rim. (Side closest to drive)

Then repeat for the inside front of the front rims and you will find the difference in numbers that way.

 

[LE#99]

Dropping the chassis loses grip (so moving the bolts to the top holes)
Raising the chassis increases grip (moving bolts to bottom hole)
Rear bearings with collars on outside will generate more grip
Rear bearings collars in less grip
Front wheels out more grip
Front wheels in less grip
Rear wheels in more grip
Rear wheels out less grip

To get more grip at Rear just leave the kart in the standard ride height and move the rear wheels in 5mm each side from the circuit.
Shouldn't need to change ride height I wouldn't have thought.

Nick, you should drop Alan Hoyle a line. He's in Boston and if you did a few days at the track.with him you would learn loads and save trying things that may not be correct. He knows cadets karts like the back of his hand and helps new starters get a springboard into cadet racing