Almost lost it in the wet Turanza ER592

[Entice]

umm..no

From my knowledge-base a tyre deforms under load. you want the contact patch to be at a maximum when braking hard, Ie, under load.

Tyre pressures are sometimes increased for safety reasons.. ie, to increase the contact patch and prevent deformation under load

[snshami]

umm..no

From my knowledge-base a tyre deforms under load. you want the contact patch to be at a maximum when braking hard, Ie, under load.

Tyre pressures are sometimes increased for safety reasons.. ie, to increase the contact patch and prevent deformation under load

It was my impression that tyre manufacturers go to great lengths to make that happen through the construction of the tyre. It is one of the reasons for having a soft sidewall so that sideways loading does not cause the contact patch to be lifted.

[93_Clubman]

What does everyone else say.

That wasn't already said here: viewtopic.php?f=18&t=45648

[Entice]

perhaps my comments were a tad perplexive.

What I was inferring is that a slight overinflation will allow the contact patch to increase under load as it deforms to do so.

At for want of a better word, "normal" pressure increased load will create a deformation that will decrease the contact patch.

in a straight line, with a softer sidewall, this becomes even more important.

[ZR]

Anyone know who stock the jap re001 in sydney?
I rang up my local bridgestone they only got the thailand one

[Guran]

Anyone know who stock the jap re001 in sydney?
I rang up my local bridgestone they only got the thailand one

I think you mean Taiwan (not Thailand).

The country of origin varies depending on the size you're after. All 185/60R14 RE001s are from Taiwan. However, the 205/50R17 RE001s on our Volvo V50 are from Japan. What size are you after?

[ZR]

lol.. yes i meant Taiwan sorry
I'm after 185/60/14.
Can we fit 195 on stock NA8 wheels?

[Guran]

Sure thing. Your rolling diamater must be within 15mm of OEM 185/60R14 diameter to be street legal. This means you can go with 195/55R14 (7mm smaller diameter), 195/60R14 (12mm bigger diameter), or 205/55R14 (4mm bigger diameter). Be warned that if you go with 195/60R14 your speedo will read very close to the true road speed, so you've got less "margin for error" with speed cameras.

[snshami]

I have an update. Last night was the first opportunity I had to drive the car in similar conditions that existed on the day that started this thread. Since then I had the wheel alignment done.

The car behaved very differently. Like on the previous wet day I was driving the car with the kind of care one takes on a wet day but this time the car did not step out even once.

So while it does not totally exonerate the tyres from blame it does point to the critcality of a good wheel alignment for our favourite roadster.

I think this makes my course of action clearer. I will prioritise my limited funds towards a rollbar, then do the 200,000 service, followed by RE001s.

Clarity is such a wonderful thing

[93_Clubman]

Clarity is such a wonderful thing

Indeed!

[manga_blue]

Clarity is completely unacceptable on this forum.

[93_Clubman]

Just picked up a new set of RE001s for the other car from Tyrepower. Made in Japan in Oct 2010.

I'm beginning to develop a theory about why people have such mixed opinions with these tyres. On my car they must be kept soft. Grip starts to fall off rapidly when I go past 28psi. 32psi seems to be about the absolute limit of driveability for public roads (though track pressures can be higher if you get them hot and sticky). Above 32psi they're pretty average in the dry and scary in the wet. In other words they work best at placarded rates of 26-28psi.

From an earlier topic here about what tyre pressures do you run there seems to be a trend that those who liked higher tyre pressures had bad experiences with RE001s. Maybe they just put too much air in them???

Phil, another RE001 recent experience at top of page here:
viewtopic.php?f=30&t=33410&start=240

[manga_blue]

Yes but I reckon track is different, Paul. For road use, where you can't get them hot, then around 28 psi works well. Go higher and it gets worse. For track use, even damp track, you can build up heat in tyres and they get stickier, so 36 psi is fine there.

Whatever, for my purposes (which are punting the car over very B-grade mountain/coast roads with a fair bit of fog and rain) I keep them soft and they're cat-like, wet or dry.

I tried dropping the ute tyres down to 36 psi (from 40 front and 40-55 rear) just to see what happened. It was horrible, wallowed everywhere and I could barely keep it in a straight line at 100 k. So going soft certainly doesn't work for all cars.

[snshami]

Yes but I reckon track is different, Paul. For road use, where you can't get them hot, then around 28 psi works well. Go higher and it gets worse. For track use, even damp track, you can build up heat in tyres and they get stickier, so 36 psi is fine there.

Whatever, for my purposes (which are punting the car over very B-grade mountain/coast roads with a fair bit of fog and rain) I keep them soft and they're cat-like, wet or dry.

I tried dropping the ute tyres down to 36 psi (from 40 front and 40-55 rear) just to see what happened. It was horrible, wallowed everywhere and I could barely keep it in a straight line at 100 k. So going soft certainly doesn't work for all cars.

55psi in the rear of a ute . That thing must skip like a flat rock on a lake.

[manga_blue]

55psi in the rear of a ute . That thing must skip like a flat rock on a lake.

55psi is actually the placarded pressure for full load. Load it up with 2 sets of wheels, spares, tools and a couple of weeks luggage and towing a 400Kg trailer with the 5 on board then 55 feels about right.