17" to 18" wheels for 2007 s60 issue

[nav]

Hey all once again, got a little issue which i hope someone may be able assist with.

As standard had 17" Volvo Orestes wheels with 225 /40/17 Tyres, have now upgraded to 18" Volvo nebular alloys made by BSS with 235/40/18 Tyres.

Problem im experiencing is i don't feel control of the car any longer. on corners it seems to grip the road but very slight bumps in the road make the steering wobble from side to side giving a bouncy effect while driving.

i have had my wheels balanced, originally only the front ones and so thought it may have bene the rear which were making me have this effect, but as of yesterday i got all four wheels balanced and tracked. steering more stable but still giving the boucy effect.

pressures in the tyres previously were 35psi, but after getting balanced they have bene changed to 32psi as advised this is the correct pressure.

can some1 please advise what it may be and how i can rectify this issue please as went for the specific setup as its a Volvo option.

Thanks

[T5frankie]

it will be the tyres mate, some follow the lines and the tracks in the road and can make you feel like the car is wandering all over the place

[ploppy]

Hi Nav,

welcome to the site,

glad you are a member !!



As T5frankie above said, Tyres ..

I had the same problem on my old V70 D5 , I had them rebalanced, car tracked and new tyres, sorted it !!

Ploppy

[JUDGENINJA]

What are the wheel width?
My Tritons and VST's were both 7.5j.
I have 235 on the Tritons and 225 on the VSTs

I can tell the difference as the tyres. The 235's are more likely to fold over and allow the bulk of the wheel,body and give you the feel like you floating, but it makes a more confortable ride at slower speeds.
The VST's keep the side wall much more rigid and therefore a harder ride, but better handling on enthusiastic driving.