Full rain track tires - acceptable tread depth?

[adouglas]

Spent some time this weekend pulling together stuff for the track day season, and was inspecting my rains. They're my first, so I have a basic question for anyone who might have direct experience specifically with rain race (non-DOT) tires.

They have no wear indicators. What would be an acceptable tread depth on full wets for continued use? Of course the more the better... but how shallow would you go before pulling the plug?

Thanks....

[Sirref]

I've raced on DOTs in the rain, here are my thoughts

The most important thing is the quality of the rubber, sometimes rains die before the tread is gone due to long term dry rot. So long as this isn't an issue the rubber should be good.

The tread determines one thing, how deep of a puddle you can maintain traction through. Beyond that it doesn't mean all that much so there's no set amount. I'd replace at 1/3rd wear personally

[adouglas]

Makes sense. Thanks.

If you ever get a chance to ride on real rains, prepare to be amazed. The only time I ever have, or ever will, pass a BMW S1000RR.....

The tire guy laid some wisdom on me: "With rains you can lean as far as you want, accelerate as much as you want and brake as hard as you want. The trick is that you can do only one of those things at any given time."

The biggest problem with doing slicks-plus-rains is the hit-or-miss weather we get up here. They absolutely paid for themselves this past year, but I did wind up riding on a drying track with them fitted a couple of times. Didn't want to risk losing it on the slicks.

[bruce71198]

Rains aren't designed to heat cycle like a dry weather tire. If you ran the tread down in the dry or semi dry condition i am going to guess you put more heat into them than they are designed to take. At this point the quality of the rubber is in question. If they have only been run in the wet and the tread is worn down to a point where you are questioning it, they are most likely done.

[Panda]

Wouldn't you be better off just running street tires instead of rains and slicks? Or do you find yourself out riding the performance of your street tires?

I've never ridden on slicks so I don't know the difference.

[csmith12]

Hmmmm.... good question Mr. Fist. One that I do not know the answer to. Honestly, I go by what my bumm tells me and visual inspection.

Rains are amazing... you will never truly know until you ride on them. Everything that you know and see will tell you can't go fast but the bike and feel will tell you that your wrong. I have raced the perilli rains in the soaking wet to semi dry conditions. I have even altered my line to run on the WET part of the track to keep the tires from getting too hot. Heat is the enemy of rains. Ask the track vets if the race line is dry, if so... time for dots. I NEVER run slicks in the rain, not no way.... not no how.



Bruce's comment is well taken, watch the dates on rains. Unless you're a hard core racer, they will not get used very often. Old rains suck pretty bad, so when you throw on your first set... make em earn your trust. And for Pete's sake, don't overheat them or run em in the dry.

Dan's comment also holds water too (puns ). Too each their own with tire choices but many, many riders cannot outride modern performance oriented tires. The power cups, the q3, the gpa's are all street legal tires and will carry sooooooo many riders into the A group of track day orgs. However, it is not my $$$$, if a rider wants to spend the money on the tires they want, I will not comment unless there is a safety concern like, running slicks on a rain day or super hard slicks without warmers on a cold day. Otherwise, it's fine by me.

Again, rain tires are a different animal, and the first time you drop a knee through a water puddle your outlook on what you can do at a wet track day changes. Best part about it isn't even the riding... wet track days clear the track. Me and one other rider have been the only riders on the track before. It's awesome to have the whole track to yourself. You will just have to trust me on that.

One other note. Mid-Ohio has been identified by race orgs as an "unsafe" track to ride in the wet, rain tires or not.... For the average rider, I would tend to agree. BUT.... the surface of the track does offer a wet line that will get you through safely if you have your wits about you. Moral here is, despite tire selection based on the many factors before you ride, be mindful that the tires much earn your trust. Build up slowly, don't go out and find the limit on the first few laps, it will NOT end well.

Happy splashing!!!!

[tgold]

Before our last endurance race of 2016 in an early practice I went out on rains to get an idea of what they were like and I wasn't really getting a warm and fuzzy feeling with them. After the practice I spoke to one of the tire vendors and he said that the pressures need to be higher than dry tires so that the water is forced out from between the tread blocks. So I took his advice set the pressures around 33 psi (a lot higher than the Pirelli DOTS I run)
We started with Pirelli DOTs as the track was dry with the possibility of rain and we were doing quite well until my second stint on the bike when it started to drizzle and I backed off as the track started getting wetter. I didn't back off quite enough though and the front end let go easy as pie in a sweeper and I surfed to a stop. It took us about 20 minutes to get the bike in and repaired and switched to rains. As I went back out I gradually increased the pace and the feel was awesome eventually getting my knee firmly down in several corners and making up a ton of time on our competition. After the end of the race the tires looked like they did before the race. (They were used and came with the bike)
Taking into account the confidence I got from the right pressures, the negligible wear, and the low hp/weight of the 250 Ninja I'l be much quicker to switch to rains at the slightest hint of rain in the future. To that end, I'm working on our bike setup to get tire swaps to under two minutes.

Bottom line: Rains are awesome if you use them right.

[adouglas]

Yeah, rains are amazing and far far superior to street tires in the wet. I'm running at 33 psi front and rear on them BTW.

Feeling the rubber and looking more closely I think I can get one or two more rainy days out of them, but this will definitely be the last season on this set. I don't actually know how old they are... they're used Contis that have no date code on them. They worked spectacularly well last year.

The bottom line really is the ability to channel water away and even the most-worn part of the tire still has nice deep grooves in it.

[Swann]

FIM rules state the minimum tread thickness for a track useable tire should be 2.5mm. The rule is about dry tires, but it's the closest I've read about for this topic.

[Swann]

2 minutes?

I am very interested in a system that can do that, if you're in the mood to share...

I have a set of spares wheels, a couple of guys and we take at best 10-12 minutes for a front and rear wheel swap.

Originally Posted by tgold

To that end, I'm working on our bike setup to get tire swaps to under two minutes.

[adouglas]

10 minutes sounds about right. But if you must have quick changes, go here:

http://www.fastfrankracing.com/

Basically you have to spend a lot of money to do this stuff. Special axles, captive spacers, captive rear calipers, brackets that allow wheel swaps without caliper removal, special spools and corresponding paddock lifts if you want to get race-quick swaps, etc. etc.

The one thing I am going for is captive spacers. A close second (on my bike) would be a captive rear caliper, but I've figured a decent workaround for aligning the bracket that replicates the function of an alignment tool.

[Swann]

Aw nuts... nothing for N300s, but the prices are mind numbing.