New Rims & Tyres

[turbomuz]

  ZapXR6T said:

As Turbo6man said, anything can aquaplane if the conditions are right, the width of the tyre makes it more prone to this condition than a narrower tyre.

I agree that anything can aquaplane but I'm not convinced that a wider tyre by default will be more prone.  Wider tyres also come with wider / more grooves and channels to disperse water.  If wider tyres degraded a cars performance in some wet conditions why would Porsche, Ferrari, Lamborghini, BMW, Mercedes etc etc all specify thumping fat tyre combo's on their top shelf performance models.  They collectively spend billions (as do tyre manufacturers) on research and development of their product and would not overlook something as common as aquaplaning.

If you put a wider rim, you will change the rolling centre of the wheel in relation to the axel.  This can lead to premature bearing failure and in some cases broken or bent axels.

Seems feasible.

With the braking efficiency, it would be reduced, just because you have more rubber on the road will not make the car stop faster.  It is the opposite, if you have your Huandi Excel with 19" rims (common, but extream example) you will significantly increase the stopping distance.  The reasons for this are that the rolling energy of a 19" wheel is significantly higher than a 14" (stock) wheel, add to that the more traction caused by the rubber, the car would not have the power to lockup the wheels, let alone take advantage of the extra traction

I'm not sure where you get this idea.  When added to the total weight of the car, the small differences in wheel weights is negligible to affect braking distances.  (Of note, my 19" with 245/35/19 weigh 1kg less per wheel than my stock 17").  You also concede here that larger wheels and tyres have extra traction!  I agree that the added traction may prevent the brakes being able to lock up the wheels but locked wheels does not equal shorter stopping distances let alone car control.

[ZAP]

Muz,

The reason you are more prone to aquaplaining is because the wider the tyre the more surface area you have to expel water from.

The reasons that the Supercar have HUGE wheels is because they need the rubber to keep a reasonable amount of traction, but these cars are also prone to aquaplaining, but you cannot compare a $2,000 super car tyre to a $500 Nankang 22" Tempe tyre special.

But the physics still remain that the more surface are the more water that needs to be removed for the car to bight into the road. The weight of a car is also spread over a larger surface area that will reduce the ability of the tyre to bite through the water.

In regards to the braking with larger wheels, there is a HUGE difference between a 17" and a 20" wheel in relation to rotational mass. While the true weight of the wheel/tyre may be within a few kg of eachother, if you spin them , the difference is massive. BCR01 may be able to give a better explination as it has been years since I worked with friction/mass calculations in relation to braking efficiency.

But I do speaketh the truth

[Lawsy]

But more surface area also = more grooves, and tyre companies put deeper channels in there wider tyres to compensate for this. The groove design plays a massive role in how a tyre performs... Tyre companies aren't stupid. Your comments (though its not your intention) indirectly is saying that they are for making larger tyres for non supercar applications.

With todays brakes, ABS, etc, you will be hard pressed to find any car that has its stopping distance increased by having more traction. Infact, excluding stupid examples (like a dato with drum brakes), I don't think you'll find even 1... And even the dato will probably stop better.

I mean, seriously, its just not feasable. The only thing limiting the stopping distance in a once off, (so rediculous heat buildup, brake fade, peddle feel are NOT the issues) emergency stop from 100km/h, is not the brakes themselves, but the lack of traction. So ABS has to kick in early...

With more friction, you can apply more braking force before a loss of traction and the ABS kicks in later... The brakes will get hotter in this second test (meanig they are disipating MORE energy), so anymore than 3 stops like this might be detrimental (knowing the poor quality of hyundia's brakes), but I don't know of anyone who needs to do 4 or 5 emergency stops one after the other in an exel...

Also, weight might play, oh, 5% in the braking equation... It plays a massive roll in overall handling, but not strait line braking... The brakes would hardly tell the difference...

I've always thought the sudden, complete loss of traction due to the tyres not having full contact with the road, is aquaplaning... Not just a crap load of water, but still having control of the car...

[Turbo6man]

  Lawsy said:

But more surface area also = more grooves,

<{POST_SNAPBACK}>

NO IT DOESN'T. How can more surface area possibly equal more grooves? By definition a groove is A GROOVE. Grooves do not contribute anything to the surface area. Surface area is the contact area of the tyre on the road surface. Where do grooves make any contact???

Also aquaplaning is a very different concept to what you seem to believe it to be. I refer you to my previous post on this to save others the boredom of repetition.

[Lawsy]

  Turbo6man said:

  Lawsy said:

But more surface area also = more grooves,

NO IT DOESN'T. How can more surface area possibly equal more grooves? By definition a groove is A GROOVE. Grooves do not contribute anything to the surface area. Surface area is the contact area of the tyre on the road surface. Where do grooves make any contact???

Also aquaplaning is a very different concept to what you seem to believe it to be. I refer you to my previous post on this to save others the boredom of repetition.

lol you totaly miss understood what I was saying.. I should have been clearer. Such a simple miss type. What I meant is that the wider the tyre, the more grooves you can fit on it. I must have just stuck surface area in there (which is true depending on how you look at it still) in my rush to get out...

The wider the tyre, naturally, the more grooves the tyre company is going to put accross the surface area. that's what I was getting at. Tyre manufacturers don't just increase the tread pattern by 20%, no, they change the groove pattern completely. They model the pattern differently to suit the width of the tyre. The tyre will be designed to disperse the same, if not a higher, volume water per cm of width...

Hope that explains what I was getting it....

It should all make sense now!

[ExAreSix]

  Lawsy said:

lol you totaly miss understood what I was saying.. I should have been clearer. Such a simple miss type. What I meant is that the wider the tyre, the more grooves you can fit on it. I must have just stuck surface area in there (which is true depending on how you look at it still) in my rush to get out...

The wider the tyre, naturally, the more grooves the tyre company is going to put accross the surface area. that's what I was getting at. Tyre manufacturers don't just increase the tread pattern by 20%, no, they change the groove pattern completely. They model the pattern differently to suit the width of the tyre. The tyre will be designed to disperse the same, if not a higher, volume water per cm of width...

Hope that explains what I was getting it....

It should all make sense now!

Ok, I think T6Man knows what you're getting at... And like he said, you're wrong.

They don't model the tread pattern differently to suit the width. Whether you have a 205 V104, or 275 V104, the tread pattern is tha same.

And looking at my 245 and my 265s, the tread spacing is the same on both.

Forget grooves. Think of the pressure per sq inch the tyre is laying down on the pavement. The more pressure per sq inch you have, the more force you have acting downward, and thus forcing (dispersing) the water along the grooves.

The bigger the footprint, the less force per sq inch you have as the same weight is spread over a larger area.

Two tyres, same design, different width.

The wider tyre will not disperse the water as well.

[iTec]

  cdm said:

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??

The Hancooks are not a bad tyre, its just constantly pushing them in highspeed turns that they really dont like. I have been looking at tyres aswell for when these ones die and am tempted by some I saw on a US website made by General that look pretty impresive.

[cdm]

  iTec said:

  cdm said:

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??

<{POST_SNAPBACK}>

The Hancooks are not a bad tyre, its just constantly pushing them in highspeed turns that they really dont like. I have been looking at tyres aswell for when these ones die and am tempted by some I saw on a US website made by General that look pretty impresive.

<{POST_SNAPBACK}>

How much? Any more details?

[Guest mercurysteve]

whilst this is all important and good chatter, can we get back on the topic?

Pics, experiences, would you buy again, are you happy etc

[cdm]

  cdm said:

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?

<{POST_SNAPBACK}>

Jusy checked.

Goodyear Eagle F1 = $435 ea about a year ago.

Once again. Great tyre, highly recommended.