New Rims & Tyres

[Guest mercurysteve]

Hi all,

With three members having written off their cars lately , I started thinking about new tyres and wider rims from a safety aspect (of course, gotta love the increased bling appeal too).

After trawling through many posts on the weekend (I am looking for new wheels and tyres) I thought it might be a good idea to start a thread where all the key info, experience, opinions and performance guides can be placed.

It would be great to have the following info (and anything else important) all in one thread for future refernce;

1) Pictures of rims (pref on a T)

2) Sizing guides (width, tyre/rim spec etc)

3) Tyre experiences and opinions

4) Pricing, where to buy etc.

5) Would you buy them again, that sort of stuff.

Personally, I have bought probably 8 sets of tyres and rims on other cars and have almost always used Falkens (mainly due to good price/no issues with em).

This time, I haven't reallly got a clue on this car, so thanks in advance for all those who contribute

[ExAreSix]

Having just bought some new rims and tyres, I'll share.

Koya Rush in Hyper Black (Available in Chrome also)

18x8. 35 offset. 70mm stainless lip.

I've mounted 265/35s on the rear. 245/40s on the front. Hankook Ventus K104.

Had a bit of experience with the K104s on my old 17s. I rate them.

Good grip, both straight line and lateral. Impressive in the wet. They were wearing pretty well.

[Goldbullet]

Heres Mine the new silica tyre good in the wet. Made by Hancook

[ZAP]

Putting larger rims and tyres on a car is NOT a safety improvement.

It will DECREASE the safety for several reasons.

Firstly more rubber = more prone to aquaplaining

Lower profile = more chance of impact blowouts and tramlining

Cheap chinease rims are also prone to cracking and falling apart.

The more rubber also can REDUCE your braking efficiency.

I am not trying to discourage you from upgrading the wheels on your pride and joy, I only want people to know that there is more against wider/higher wheels than there is for it.

The only advantages is traction in the dry and athetics.

[iTec]

1) More pictures of wheels

2) Wheels are starcorp Impul 19x9.5 rear and 19x8.5 front.
Tyres are Hankook Ventus Sport k104 275/30R19 rear and 245/35R19 front

3) The tyres become very slippery (oily) when you are really pushing the car in the twisties, I think tyre wear is pretty poor because of this reason (5000km 50-60% tread on the front and rear). rear end traction (40psi) is excelent if the road is flat but bumps/drops camber ect all play a negative effect in a big way as the wheels bouce (partly to blame is the stiffer springs I I have). grip in the wet is okay but 275/30 competing with 240kw still means you get wheelspin if you try taking off to quickly from the lights however front traction in the wet is still pretty good, these tyres move alot of water (people hate following me in the wet) and that is probably the one thing that saves them.

The wheels, buckle pretty easily, I hit a pothole (small/medium) at 40km/h and it buckled the inside lip of the wheel, which seems to be the weak point with these wheels. this however was at 40psi with 48psi they seem to cope a bit better (I hit the same pothole a little quicker and received no damage)

4) $2400 for the lot from tempe tyres, there currently out of 19x8.5's in shadow chrome but they should have them back in stock soon

5) would I buy them again? the wheels definatly 100mm deepdish looks very tough so does the 9.5inch wide rim, I am however looking at getting some better tyres and possibly going to a 2**/35 rear tyre

[cdm]

iTec, as you may know, I have just purchased the same wheels as you so it's interesting to hear your advice re the buckling rim. If you were considering running 285/35/19 the tyre choices are fairly limited. The only ones I could find in a brief phone around were Dunlop SP9000 @ $820ea and Bridgestone Potenza's @ $790!! I also spoke to Herrod who say that you would need to have 40mm offset in order to run this size without rolling the guards (eg, DJR car).

I can't really find a good 275/30/19??

As far as 18's go I can highly recommend Goodyear Eagle F1. I have had variouis tyres over the years in 16/17/18" and these by far have provided me the greatest satisfaction. Good turn in, good traction, predictable in the wet. And pretty good wear. Mine have about 25000 hard mountain km and have been rotated twice and still have about 30% left. I can't remember exactly how much they where but I get the feeling they were around the $450 mark each. They weren't cheap but they were worth it.

Zap, surely there must be a point where the advantages and disadvantges of wider tyres balance out. What are the narrowest tyres that a Falcon comes out it? I'm guessing it's 215 on a 15" rim or something, whereas the XR's run (optional) 245/40/18 and I think the FPV's may run slighlty wider again?

[ZAP]

  cdm said:

Zap, surely there must be a point where the advantages and disadvantges of wider tyres balance out. What are the narrowest tyres that a Falcon comes out it? I'm guessing it's 215 on a 15" rim or something, whereas the XR's run (optional) 245/40/18 and I think the FPV's may run slighlty wider again?

<{POST_SNAPBACK}>

As far as I know there would never be a balance.

There will always be more disadvantages going to larger wheel/tyres unless you modified the car to suite the increase. I guess I should have made my previous statement clearer, I am referring to a stock car.

If you put larger brakes, increased the wheel well size to allow for a larger wheel with the same rotational center, you would reduce the negative effects of going larger, but you would still have the phyical disadvantages of a larger wheel in relation to damage from potholes, etc.

Cars are engineered to accept a certain wheel size, if you increase the wheel an more than 1inch wider or higher (in NSW) your car can be defected. This means that 20" rims are illegal on the XR's and can cause you issues with insurance and cops.

[Lawsy]

I agree only to a certain extent with you zap.

Most wider tyres these days have a deep central groove and deeper tread patterns. These pass the water more efficiently than tyres that do not have a central groove (most tyres under 245, not all, but most).

Also, aquaplaning in a 2 tonne car is rare anyway. Its very difficult to truely aquaplane such a heavy car (we've tried). Also, physics dictates that your braking distances MUST be reduced with a larger contact patch on the road (assuming the tyres friction coefficient is the same). Its simple physics; physics doesn't lie.

You also need to realise that the BA range was built to safely, without modification, accept 19 inch rims/tyres.

And lastly, the rolling circumference of the tyres is not much greater than the standard package anyway; the profiles people are purchasing these tyres in are usually allot lower than the standard profile... I've posted these figures before but I'll post them again just as a reminder.

Circumferences are in centimeters. These are the more common aftermarket tyre sizes purchased for the BA (you can see why).

Speed is @ 1909rpm (100.02km/h) in 6th gear using 245/40/18 as the control, rounded to 2 decimal places.

235/45/17 = 202.0986554... 98.51km/h

245/45/17 = 204.9260888... 99.89km/h

245/40/18 = 205.2088321... 100.02km/h

275/35/18 = 204.1092747... 99.49km/h

245/35/19 = 205.4915755... 100.16km/h

265/30/19 = 201.5645847... 98.25km/h

275/30/19 = 203.4495402... 99.17km/h

285/30/19 = 205.3344958... 100.09km/h

So in reality there is only a negligable difference in the speeds, little difference in safety but with a greater road holding ability (in all conditions) as well as better asthetics.

I cannot see how you draw a conclusion that there are more negatives than positives to getting larger rims (appart from the cheap crap that buckles as soon as you hit a pothole at more than 30km/h)...

[Turbo6man]

  Lawsy said:

I agree only to a certain extent with you zap.

Most wider tyres these days have a deep central groove and deeper tread patterns. These pass the water more efficiently than tyres that do not have a central groove (most tyres under 245, not all, but most).

Also, aquaplaning in a 2 tonne car is rare anyway. Its very difficult to truely aquaplane such a heavy car (we've tried). Also, physics dictates that your braking distances MUST be reduced with a larger contact patch on the road (assuming the tyres friction coefficient is the same). Its simple physics; physics doesn't lie.

<{POST_SNAPBACK}>

Are you sure you're talking about aquaplaning and not loss of traction???

Believe me it is VERY easy to get a 2 tonne car to aquaplane. Aquaplaning occurs when the rotational speed of the tyre exceeds the tyres speed of "pumping" the water clear of the contact patch. It has very little to do with the weight of the vehicle or the co-efficient of friction and everything to do with speed and tyre design.

PS I've had a 12 tonne bus aquaplaning - and I don't mean just sliding sideways on wet tarmac - but literally aquaplaning in a straight line.

[GlennAUII]

itec those are stunners man! ExAreSix, I'm loving the new rims too!