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I'm really enjoying reading the contributions to this topic. Would it better off in the tyre section maybe?
i think its an idea to get a 4 wheel alignment as soon as possible on a new car,half of the time the alignment is good,the other half its out big time. and for the sake of $50 its piece of mind.
After only 27,000 km out of my first set of 18 inch tyres (worn badly on inside) I decided to get specialist alignment advice. My car has had the standard springs reset to lower height and this increases camber. The alignment guy fitted a pair of camber adjustment bolts from pedders to the front end. He then set alignment to 1mm toe in on rears, zero toe on front and much less front camber (from memory right side zero and left 1/3 degree or something similar). Without the camber adjustment bolts the standard set up doesn't allow for any camber adjustment. He said this is the cause of most front wheel drive tyre wear as the rear has little weight. He also suggested drop rear tyre pressure down to 30-32 psi (for 18 inch) versus 40 psi on front- this will improve flat spots wearing. Camber kit and 4 wheel adjustment cost me $200 which is well worth it, he also adjusted me park brakes on the rear. I'm confident the next set of tyres will last much longer as they should wear evenly. (touch wood!)
But of course our GD i30's have torsion beam rear suspension so that probably changes things........
It seems to be accepted that torsion bar suspension is not as sophisticated as full IRS. However, there is an interesting discussion here though.Firstly, it's cheaper to manufacture and probably less expensive to maintain. This is good for the manufacturer I suppose.The dynamics of shock vibration and lateral stresses on the car are dealt with by the wheel experiencing the forces in IRS. That is, the left rear deals with forces that act on the left rear. In torsion bar, there is a design decision to actually deal with these forces on the opposite side of the car (because that's where the other side of the torsion bar is anchored.) This is directly opposed to the IRS method. Which one is best, I don't know. My feelings are that if you design to involve the other side, it could be advantageous because the disruption is distributed over 2 wheels instead of 1.Maybe surferdude, with his rally and professional experience knows more about this.
Bobbyd, that sounds like a good move.FWIW I think the camber settings your guy has gone for are pretty good.I also agree about the pressure - 32 psi would be good. This is because once you get into 40 series and below, there is so little sidewall flex that the need for a higher pressure is negated. Also, higher pressures in low profile tyres can cause some centre rib wear due to the effects of centrifigal force if you spend a lot of highway speeds.I would have loved to see pics of your old tyres' wear patterns. When you say flat spots, were they on the front or the back, inside or outside?
QuoteBobbyd, that sounds like a good move.FWIW I think the camber settings your guy has gone for are pretty good.I also agree about the pressure - 32 psi would be good. This is because once you get into 40 series and below, there is so little sidewall flex that the need for a higher pressure is negated. Also, higher pressures in low profile tyres can cause some centre rib wear due to the effects of centrifigal force if you spend a lot of highway speeds.I would have loved to see pics of your old tyres' wear patterns. When you say flat spots, were they on the front or the back, inside or outside?The flat spots are assumed to be from the rear, thats what the alignment guy says but i rotate the tyres every 5000 so i have to take his word for it, he says any out of roundness in the tyres is then exacerbated by high pressure on a light rear end car and higher speeds. the flat spots were quite noticeable and two or three on each tyre on the inside mainly, the rest of the wear was on the inside of the tyre and the middles and outside still had some meat on them.
