RE-71R experiment?

Z1NONLY

The new RE-71R "street tire" from Bridgestone seems to be running and more importantly wearing, like a race tire with a tread pattern...and a 200 treadwear rating to make it "legal" for the street-tire classes.

Many people seem to be reporting accelerated wear over previous street-tire offerings from various manufacturers. I would like to quantify this in an experiment.

I'm considering:

1)Fitting a Miata (small, cheap tire sizes) with RE71R's on one side and RE-11A's on the other.

2)Use a traction circle and a pyrometer to set appropriate air pressures for each pair of tires.

2)Constructing a symmetrical course and running it in both directions, repeatedly, with consistent drivers. (-making sure that each driver splits their directional numbers evenly)

3)Document wear with before and after tread-depth measurements and pictures.


*IF* there is a huge difference between two different tires that a single manufacturer has rated with identical tread-wear ratings, then I think it's fair to say that Bridgstone was incorrect with its treadwear rating process/number and the exclusion list should be considered.

If the RE71R's wear similar to the RE11A's, great. But if there is a gross difference in wear, the SCCA has an exclusion list and the RE71R should be on it.

I fear that allowing tire manufacturers to stamp "200 treadwear" on the side of a compound that isn't even close...without repercussions...will be bad for autocrossing.

So, before I bother to set up this process:

-Does anyone even care?

-What other variables should I try to control for?

Owen

Care.

Somehow you will need to try and control for camber.

O

Z1NONLY

I am considering getting the alignment checked before and maybe even after, but all I would be looking for is symetry from one side to the other.

The pyrometer should show what's going on with the contact patch.

chrischhorn

I care especially because I have an STS Miata but you are correct in previous driving done from other forums. The RE-71R is basically an R-compound with a 200 TW rating. PROBLEM is that the TW number is not regulated in any way or by any one other than the company themself. A 200 TW tire from bridgestone can mean 10k miles wear while a 200 TW tire from Michelin can mean 30k. Its just to compare to each manufacturers own tires so if the RE-71R's get 200 TW and get 10k miles. Their next tire like the S-04's can get a 300 TW rating 25k miles worth of wear.

Why do you think randomly once the 2014-15 rules were announced about the 200 TW rule for any Street class that all of a sudden the RS3's, the RE-11's, the Direzza's and the Toyo R1-R's all randomly became 200tw. They didn't change anything on the compound but yes I'd love to see some testing of how the RE-11's and the RE-71R's compare. I'm running RE-11A's on my Miata right now.

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j-rho

There's going to be enough people driving them on different cars, the real longevity story will be evident soon enough.

AK370Z

You want RE-11 vs RE-71R comparison?



If I had a pair of rear sports pack rims, I'd do it. I have a pair of extra front rims but no rear rims. The Re-71R just showed up on Friday.

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stuy486

TireRack already conducted a back-to-back test of these two tires.

There's no talk of wear in that test, but I don't think you're test is going to answer that question either. There's a lot of factors that go into it, I think it's a pretty car-dependent issue. On our STU 350 we're not seeing wear that's crazy. We've got ~500 highway miles, 3 TnT runs, 12 Tour runs, and 24 ProSolo runs on them and they're looking fine so far, we're confident they'll make it through the next Tour and ProSolo events just fine. Are they wearing faster than a Hankook would? Probably, but it's not as bad as people are making it out to be.

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j-rho

Got about 400 street miles and 14 Prosolo runs on mine, they look good. That's with a 3200lb. 370z on skinny little 245-18's all around.

My expectation for street tire wear - and what I used to get on my STS 240sx back in 2006 - was 10 ~60 second runs (or ~10 minutes on the clock) per 1/32" of tire. Will have to measure depth on these to see how they're doing, but so far they appear to be in that ballpark.

Z1NONLY

The time difference is similar to what Ruggles experienced between RS3's and the RE71R's.

It's huge.

However, the most recent pro solo didn't show the same disparities.

Robert Yuras

So which size is everyone using on the front? The 245/40? or the 255/35?

And why the heck dont they make a 295!? GRRRR. I want 265 front 295 rear!

PharmDZ

On the stock sport rims I'd run 275/35r19 square.

AK370Z

whoa are you guys on RE-71R too? or talking about RS3 v2? haha if you guys are RE-71R, we need to create a Potenza club! haha ..

My first event on them (RE-71R) this Sat. They are at 0 miles right now. Just curious, what tire pressure did you guys end up with? I was thinking 38F/35R?

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cjwsrt6

I ran these psi settings on my 285/35 rivals and have already torn off chunks of tread off the outside of the fronts, I wouldnt recommend these tires to a stock 370z with the little camber we have. going to try the new kumho when it comes out if the re-71r wears too fast

FPenvy

I was just looking into these since they seem to offer the sizes I want 265/305 19

if you know Japanese it may help......

クãƒ*ホタイヤジャパンæ*ªå¼�会社 - タイヤラインナップ - ecsta V700

the sizes it shows are:

225/40/18
245/40/18

235/35/19
245/35/19
265/35/19
305/30/19

also in 17, 16, and 15 as well.

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FPenvy

blog post on the kumho as well for any interested. just copy paste into Google translate. all in Korean.

금호타�어 블로그 Dr_tire

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