How Are RE-71Rs In The Wet?
 

I'm looking to get some Bridgestone RE-71Rs for street class autocross. Does anyone have experience running them in the wet? The tire description mentions reduced hydroplaning resistance, but the TireRack survey gives them a good score in the wet. I'm trying to figure out whether I can leave them on the car for the autocross season, or have to switch out rims/tires for each autocross event (yes, I'm a lazy SOB).

I live in the Pacific NW, so there would be plenty of wet-weather driving involved, both at autocross events and just daily driving to/from work.

Lets put it this way. my time with RE71 was only .16 sec faster in the afternoon than my morning session with stock tires. both sessions were wet as hell.

similarly, Annie Gill is running with her MPSS instead of RE71s on a wet day.

Do you daily drive on the RE-71Rs at all, or just put them on for events? I'm also curious about whether they're safe to daily drive in a wet environment like the NW.

they heat cycles out really quick so i dont daily mine. like you i swap them on when i get to the event. im in WA, so i know the feeling.

I run RE71Rs on my FRS and I've had them in the rain. I was concerned as well about Bridgestones wet driving warning. I only have 1 track day on these tires and about 9,000 street miles. Hydroplaning has not been an issue for me.

Actually, I found the wet grip to be pretty good, with no odd surprises when they let go. The grip seems to fall off more in cold temps than it does in the wet. They would be fine for PNW daily driving but it is worth considering using them as a 2nd set for autocross/track only.

What do you mean by this exactly?

They're fine in the wet. You may run into issues if you're low on tread and go through puddles, though.

So true but wouldn't that be the case with any tire choice?

They're called cheater tires for a reason: they're incredibly good in everything except snow and ice. The drop off between dry and wet (read: wet, not puddles) is not much from all the top folks I've talked to. However, they do drop off quickly so tire life is an issue but fresh tires to fresh tires, they're insanely good.

Especially if your driving is fast and quick right off the bat as opposed to building up over time.

They are great in the wet as long as full or near full tread.

With conventional tires, you usually judge how much life it has left by looking at the treads. The Bridgestone RE71Rs is a special compound tire, where it not only depend on the tread life, but also the amount of heat cycles. usually the tire loses its peak performance after a certain amount of heat cycles, this is the case with many high performance tires, including MPSS(but you may not notice unless you put the car into a competition environment).

Heat cycle is when the tire warm up to the design temperature and cool back down to ambient. The rubber compound loses its "stickiness" as it pass the optimal amount of heat cycles and become hard. RE71R is notorious for that, which is why right before the SCCA Solo National Championship, veterans are getting rid of their "older" RE71Rs even when they only raced 2-3 events with them. So if you daily them, you are putting it thru the cycles, and by the time you get to the track, its not as effective.

At least this is how i understood it by talking to the pros. hope it made sense.

All true points, but with regards to daily, I sincerely doubt you're able to get enough heat into the rubber just driving around in the city where you would actually heat cycle out the tires, so this shouldn't be a concern unless constantly doing canyon runs in between track sessions where you actually work the tires.

I have a set on my FRS 265-35/18, and here is my experience.

1. At low speed, and with wet pavement but no standing water, they are very good. I imagine the compound is the important part in this situation, and it is excellent in the wet.

2. As speeds increase and the layer of water gets thicker,(as in even the shallowest of puddles) the tread shape and ability to channel water becomes the key, and then they are pretty bad. This tread shape makes a lot of compromise in order to maximize dry grip.

3. If I was dailying my car on the freeway, I would get another set of tires for the wetter months, but if I was only driving a few miles on side streets I might just try to get away with it.

In my experience the RE-71R is fine for normal wet roads and puddles. I have not tried driving in standing water with them (such as minor street flooding, shallow stream fords, autox in torrential downpours, etc) but I used them as my daily tire for most of the summer and during plenty of rainstorms. And I've autocrossed with them in the rain, and found them to be predictable and grippy. This is on a tire with plenty of tread remaining, though.

Sorry to digress from the topic. But I have always wondered, can this "stickiness" of the compound be quantified? Perhaps by using a tire durometer?

I am currently using the RE71R as a daily as well, have ran them through torrential storms on the highway (no standing puddles) and they hold up pretty well. Not at very high speeds of course.

Pretty much. As long as you have some tread and you're not stupid you should be fine.

Thanks for all the responses, folks. Based on what I'm hearing, I'm going to go ahead and daily drive them. I have a short commute on city/surface streets (after 10 months, my car has less than 4,000 miles on it), so it should be fine. If I do hit the freeway in the rain for any reason, I'll take it easy.

We all wish that it could.

Tire durometers can tell you how soft the compound is, and that is often used to evaluate "stickyness" but that only gets you in the ballpark.

If there was a tool that could accurately measure potential grip, we wouldn't all have to go out and test tires every spring, we woud just go to the tire store and measure them.

Was pondering over what slyphen said regarding the tyres hardening over heat cycles and whether a durometer can "measure" that. Not so much over how much potential grip the tyre has. Apologies if it was interpreted differently