View Full Version : Chassis set-up problem
12-02-2007, 12:23 PM
I have a 125 CR32 SP and i have serious grip problem. My chassis is balanced front and rear, when i test it it feels ok (balance) but it sides in all 4 wheels. The track is new and the asphalt is very slipery. My competitors are 0.8 seconds faster than i am(Intrepids, CRGs etc). As the rubbers comes again the chassis has not much gri[p all around, but my competitirs are faster and their chassis have very good grip. I tested many things, STD set-up, all sort of preesures, seat positions etc and stills the same, very little difference.
My fastest set-up is as follows:
Pressures: 0.8 bar all around
Axle: yellow( not tested any other) Position: UP
STD rear and front hubs
Front bar IN Rear OUT
Spindle position: STD(middle)
Rear Track: 139.5
Front Track: 5 lines
Seat Position: T11 19cm from the axle 60cmm and 62cm 10mm below chassis.
Rear bearing INSIDE
Camber/caster pills 0.5 up and down with eccentric looking back
Rear bumber bar loose
2 seat struts each side
I cannot tranfer speed on corners especially tight ones. Coming out of tight corner the back end tents to spin and slides the chassis out.
Please let me know what to do to achieve more grib.
Thanks in Advance
12-04-2007, 12:37 AM
I'm bored tonight, wandered onto these forums, so here I go:
When you say "yellow" axle, you mean a 40mm axle, correct? Let us know what axle it is. Over by your left rear wheel hub will be a number like, "40x2x1040 F". Let us know that.
If your rear end is sliding around and trying to beat you out of the corner, it's possible that it is being cause by understeer coming into to the corner. Does your chassis turn into the corner fine? If so, here are my suggestions:
Longer Rear Hubs
Harder Axle (Again, let us know that number so we can make a recommendation.)
Put the axle in the "down" position. Axle down, chassis up.
Try these things and let us know.
Motorama Kart Parts Customer Support
12-04-2007, 03:20 AM
My axle is 50mm Freeline Yellow 1040mm. The front end is not perfect.I need more turning in.
12-04-2007, 11:26 AM
It the front of the kart is pushing on turn in and the rear of the kart is sliding on corner exit I would say that the kart really isn't balanced. For a low grip situation I would have the chassis raised front and rear (spindles and axle down), B or D axle (softer than what you have), 1 degree of caster in (kingpins leaned back), and I would more than likely have all of the bars out to help the kart twist and work. Your seat position isn't too far off except for it might be a bit low...I would raise it straight up so that the bottom of the seat is flush with the frame rails. You should test the bars one at a time...start with the front bar in, go five laps, then try it with the front bar out. Do the same with the side rail. 4 seat stays might be a bit much on a track with no rubber...have you tested with one per side or none per side? These are quick changes that you can make in the pit lane and get an immediate answer as to whether the kart needs to be soft or stiff. I hope this helps and let me know if you have any other questions.
12-05-2007, 12:19 AM
If that's the case, before you try the other suggestions I made, try this to fix your turn in problem and it may correct your loose off condition:
Widen front track width
Do you have the dual front bar setup? If so, add the long bar, take out short bar.
Move your spindles down, which will raise the front end of the chassis.
Try one thing at a time in gradual increases.
12-05-2007, 01:04 PM
Hi Chris, Thanks for your advice,
If i move all the seat up what will happen and if i increase the distance from the axle from 19cm to 22cm what will happen?
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