TrainTracking / Bump Steer ........... what is the cause

[VL Berlina 5speed]

ive had this problem with my vl and vs

when i have my 18" HBD j series rims on either i get train tracking or bump steer,

bassically if i pulling up to a set of lights the car will try pulling into the grooves on the road or will try turning when hitting a bump.
the point where you cant let go of the wheel or lightly hold it as it will try jumping about

now we have since purchesed a vy ute which came with 18" HSV avelanche rims and it does not get this problem.

last week i put the HSV rims on the vs and there is no train tracking or bump steering at all

now im leaning towards it being the rims or tyres which would be causing this
i always thought it was just because the tyres were wider and picking up the grooves more but this proves other wise


would there be any off set diffrence in these rims? would this cause this prob or would it be the tyres which cause this problem?

[Tom_1569]

When I got the ute it was terrible, I couldnt open a bottle of drink as I always had to hold the wheel straight.
I got new shocks (they were stuffed), but straight after getting shocks and springs I got a wheel allignment. Its no fixed I can take my hands right off and it just keeps going straight. I dont think it was the shocks, more so the wheel allignment which they said the toe in was "completly ****ed."

[andyman]

basically anthing that affects the steering axis from factory settings will cause it, so wider wheels, lower suspension, alignment etc etc

[VL Berlina 5speed]

well the struts are both fairly new on the vl and vs and dont bounce
the vl has king spring lows and the vs has Fe2
the wheel aligenment is spot on but toe in i havnt looked at

but im thinking its not the car/suspension,
my HBD rims make the vs bump steer where the HSV rims do not

only veriable is the tyre and rim, not changing any suspension

so im thinking tyre pattern or possible offset diffrence if there is any

[vlv8vic]

had the same problem in the vl and it only had 17s i think. sold it. problem solved.
It did improve slightly once with a wheel alignment, but living down a dirt road meant those tweaks never lasted long.

[Dan355]

Directional tyres are known to make the tracking problem on larger wheels. Profile of the tyre affects this the most.

[doms3]

Tyres ,have had probs with one brand and not another

[Morton]

Tyre tread, sidewall and alignment have a lot to do with it. If you get a little more toe in, and get some asymmetrical front tyres, things should improve. I think you need more toe in with lower profile wheels.