Bench Racing Ammo: Tire Testing
Thursday, February 21, 2013 | 11:30 AM
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“This is the third loop with this front tire,” says Pirelli North American Off Road Manager Josh Whitmire. “We spent a lot of time in the off-season with the rears, but we’re always working on fronts. We’re going to try something new that can race this weekend in Atlanta.”
“Loop” is Pirelli’s term for each version of a new front tire. This is the third generation of a prototype tire, and when the brand’s main research and development partner, JGRMX, decides they’ve finally found the perfect front, that tire will go into production. Thanks to the R&D learned in the first two loops of this tire, this third-gen test will be a little simpler. They know what direction they want to go; now they’re into the details.
It’s a Wednesday at the JGR test track in Mooresville, North Carolina, and it rained yesterday. But track builder Mark Barnett recently redesigned the track, so it’s fresh. The track is well engineered for drainage—the entire track is elevated above the natural surface (even the bottom of each jump transition sits about three feet higher than the ground) and there’s an elaborate drainage system, too. Wednesday sun does the rest, and Justin Brayton is able to roll out on his YZ450F and cut laps early in the afternoon. First, Brayton goes out on his current race tire to make some baseline notes. He cuts lap after lap to put some lines into the fresh track. Then he heads to the shop so they can swap in a new front.
Brayton starts the day churning laps on the tire he races with each weekend.
Then JGR R&D man Spencer Bloomer steps in to put on the new hoop.
Brayton then logs more laps. Pirelli has been working on stiffer sidewalls and knobs, which pays off in corners like this.
Weigandt photos
The SX tracks this year have been pretty hard and slick, so you’d think traction is the main issue here. But Brayton and the rest of the Pirelli-shod riders have been satisfied with grip. (The other Pirelli riders include JGR teammate Josh Grant, and BTOSports KTM’s Matt Goerke. Kyle Chisholm is riding for JGR while Grant is out with an injury. And now Andrew Short is on board with BTO, and he was trying tires in California this week.) For Brayton, this test session will be as much about the tire’s impact on suspension performance and feel as traction.
Tire companies are always chasing a moving target. For one, track surfaces are constantly evolving. East races like Atlanta and Indianapolis used to be known as rutted, tacky, sticky affairs. Often now, they’ve become dried out, hard and slick. Tat Kimsey, Pirelli’s MX/SX technician, notes that a Monster Jam event just took place in the Georgia Dome, so the dirt has been sitting in the building for awhile, getting drier and drier.
Today, Pirelli has a few new front tires, and each will help determine what direction they ultimately want to go. Brayton does a bunch of laps on the first new tire. He likes it, but during the debriefing with Kimsey and Whitmire, he says it feels much different. “With the tire we’ve been running, you can feel the rut in those whoops,” he says. “With this new one, you can’t feel anything. It’s not quite wallowy or mushy, but I just don’t even feel the rut.”
Brayton is sensitive to how a front tire works in ruts—he tends to run a narrower front tire because of this. Three years ago, JGR was testing with Pirelli in anticipation of switching to the brand for the 2010 season. The tires worked well, but Brayton and the team weren’t sure about the selection of narrow fronts at the time, so they stuck with Dunlops. For 2011, the team switched to Pirelli, and Brayton and Davi Millsaps worked hard in tire testing to help them develop a new generation of tire (Whitmire says the production Pirelli tires now are based on what they learned from Millsaps over the last two years).
When JGR brought James Stewart on board in ’12, Pirelli stepped their program up further. They were working so quickly, they were literally stopping their production line in Brazil, producing prototype tires, and overnight shipping them (from Brazil) to California. The cost for that shipping bill? 60k! Another time, Kimsey was testing in California, and needed to try a tire that was back at Pirelli’s U.S. HQ in Georgia. So he sent his son to the airport with two plane tickets—one from California to Atlanta, and then another one to come back, in the same day. “He flew home, grabbed the tire, and went right back to the airport,” he says.
“It got to the point where we were literally going to airports and buying tickets at the counter,” says Whitmire, as they tried to race on the West Coast, work in Atlanta, and produce in Brazil (the tires Brayton was testing on this day even had shipping tags in Portuguese, the native language of Brazil).
Straight out of 'Brazil!
Brayton and JGR Team Manager Jeremy Albrecht chat with Pirelli's Tat Kimsey (left) and Josh Whitmire.
Then it's back to more test laps.
Weigandt photos
They also spent a ton of time at Stewart’s compound in Florida. At one point, Stewart even joked that Kimsey had pretty much just moved into his house. It has been a lot of work, but there’s a reason. Globally, Pirelli is known as a high-end tire maker, and they’re the official spec tire of Formula 1 and World Super Bike. They’ve also had great success in motocross on the GP circuit, with Jeffrey Herlings and Tony Cairoli bringing home the 2012 MX2 and MX1 titles on the tires.
In all, Pirelli has produced a staggering 720,000 racing tires for series around the world. But they’ve been considered a bit player in Supercross compared to traditional powerhouses like Dunlop and Bridgestone. With JGR and BTO, they have a chance to prove their worth. They’ve even developed a relationship on the amateur end with JGR, as just last week, the team announced that they’re handling Pirelli amateur support, and have begun accepting resumes.
Brayton giving us a good view of the tires.
Weigandt photo
The hope is that the lessons Pirelli has learned working with Stewart and Millsaps in the past, and with Brayton, Grant and the BTO riders now, will help improve the product.
Brayton rolls out on another new tire, and this time he finds what he likes. “I feel like I can drive into the turn in so much harder,” he says. “I was driving in extra hard on purpose and it just stuck.”
“The tires we have been working on now have extra-stiff sidewalls, and a lot of work going into reducing flex in the knobs,” says Whitmire. They can bake a little flexibility back in via the rubber compound, but overall, Brayton seems to like the stiffer design. He goes back to the old tire just to be sure, then tries the new one again. He selects the new one for Atlanta. Today, the team will ride for press day in the Georgia Dome, so Brayton will try it again. If all goes to plan, he’ll race with the new tire on Saturday, another step forward in the evolution of the program.
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josh, I thought I was looking at bp for a sec in that picture!
but its good to see that you are doing well!
Good job Jason, very interesting story on tires and timely too, with all the traction issues we have been hearing about. Any thing from the Dunlop side, since they are the official tire of Supercross?
Love that Carolina Clay!! This time of year doesnt get any better !
To your existing formula Add 30 gms more Code1, 50 grams more NOLO {Natural Rubber} and 30 gms more Urbanine, 100 gms more Carbon black x7101 and you will get in the ball park.. adjust the heats on the banbury 20c up and mix 20 seconds first stage more ... on stage 4 add your oils for the intial mix
I know I worked there ! I developed formula's .........
Glock you never cease to amaze!!!
Nice read, really complicated figuring it out when you have a tire you like but then go to a new track and change suspension setup, motor characteristics, gearing which affects the handling and then maybe that tire is not the best anymore....lots to figure out...very interesting.
Tires I love tires, especially when they are brand new and at the shop on the tire rack! Almost as good as the old VP leaded race gas! I was so tire pecky that I had different tires for different tracks. Sometimes I would even change tires before the 2nd st of moto's. In the early days I liked the original Metzler Moto tire, bothe front and back. For mud or deep loam I would run a hard compund Treleborg on rear and the old Barum front tire that came on the CZ's, I liked the knobs on the sides so I could climb out of ruts. CZmark should remember that tyre as I think they were the stock tires on the CZ's.
Then I found the Dunlop 752's They were great front and rear untill late in the day in Texas then I would change to the Bridstone M23's. They stuck like glue.
I dont know what tires are nowdays since I retired in 95 I think?
Yes this was a good article and very interesting. I really did not like it when the promoters started useing concrete starting pads because I could see $$$$ floating away on every start!
@ Glock---- Locked and loaded! Just as we shold be, Long Live the @nd Amendment, I just hope bama does not ruin it!
Looks like Pirelli is trying to improve their dirt line ...which they REALLY needed to do....you might want to test on some crappy concrete like dirt instead of that nice looking clay....hey heres an idea have JGR haul some practice track dirt to the stadiums...then your tire works and we can see more lines of racing..win win...lol
@BD25 give me a clue that only I would know if you have been around as long as I have? I raced in TX for all of the 80's Knew a couple of fast people? I even won a race once! It was at Chicken licks raceway. That is what Jody called Mosier Valley.
I remember Trellborg! They had an orange line around them. I bought one once and that tire had more traction than I ever had it my life, but the knobs started chunking off. I fell in love with Michelin Mh2's because they fit MN soil the best all around.
Very cool that Pirelli is going for it. I would LOVE to see a Brayton win
Welker I was never a fast guy, but I have been around the sport since the 74. My first trophy came from Ponca, 4th in the 250 novice class. I had a friend named Eddie McDoniel, who used to race at Moiser Valley, as an Intermediate in 77-78 on a Kawasaki 250. Being from Oklahoma I was around when Trey Jorski was dominant, Clay Hoenshell and John Baker, whom I sponsored, used to chase him around 59th an Douglas. I enjoyed nationals and Trans Am's at Whitney watching all the greats of yesteryear race, even managed to meet a few. I watched as Cooper and Reynard's careers took off and have had them at my house, riding my track while they were factory guys..I have met, talked with and interviewed a lot of riders over the years and have been a fan of all of them...Motocross and Supercross has been the one constant source of enjoyment in my life ..At 55 I can say I have been very lucky to have seen what I have seen and met those I have met and I am not done yet!! So have I been around as long as you have???
Ah nothing like new sneekers for you scoot. Maybe they can come up with the first stadium tire for that asphalt they have been racing on.
@BD25-"At 55 I can say I have been very lucky to have seen what I have seen and met those I have met and I am not done yet!! So have I been around as long as you have???" So true, we are very fortunate!
Welker-you can still buy Barum tires today, new old stock of course. Mostly for show, otherwise those knobs would rip right out.
Love articles like this RacerX!!!! Thank you for posting this. I live in Mooresville and regularly see Brayton around town with his Yz450f in the back of his tundra. Maybe you guys could start doing more stuff like this on how the teams test different parts (at least the ones they will let you see) because personally I love reading about setups and how they improve how the bikes work through different things. Thanks again!!
Oh and Weigandt, wanna go to lunch sometime your in Mooresville?
Any one remember the Tera-flex rear tire? It was a clod throwing son of a gun on the back of my RM 400...
I used to ride and race mosier valley in the late 70s and 80s was sad when politics shut it down
@ BD25
Heade thru Wichita on 70 headed to KansasCity.. LOL Ran into an Hottie friend Mary-Rachel Redman from KOCO-TV(ABC) in Oklahoma City, Now over at KSN Sports she would do SX-Mx real proud !
@ DB25 Remember Trelleborg ! Well I need them today for the car ! LOL..
Winter Friction Studded Tires
During a trip last year I had a rain- and snow-filled trip to Oregon, I took a set of Trelleborg’s Winter Friction studs along for a wintry-weather test ride. They don’t have to be strictly used on ice; some riders back home have been swearing by them in the red clay mud of the Southwestern Oregon woods for years. Just as I geared up for the ride, the skies let loose with a rain-snow mix, making for perfect sloppy-snow conditions.The clay at lower altitudes was pretty slick when it rained, but the studs gripped the soggy ground better than any standard tire with fresh knobs on a perfect day. Places where I normally had to be very careful with the throttle to not spin out were blasted through like I was on a rail. On hillclimbs that would have otherwise required a run, I could stop and start again without spinning the wheel. And those treacherous logs-the ones that have the bark stripped off and are nearly impossible to ride over when they are wet-were no problem at all. It was almost as if I had spiked tires. Wait a second, I did have spiked tires.As I climbed 3000 feet into the mountains, the rain turned to snow and the soil was frozen in spots. The ground was loamier and rockier higher up, too, but the studs worked just as well there, especially on frozen ground and packed snow that has melted down a bit and refroze. The only place they didn’t work extremely well was on the big, imbedded slabs of rock. There they slid unexpectedly under braking, and they did kick more than standard tires when impacting a stone of decent size.Mounting was a little more difficult than with a standard tire because the sidewall is stiffer and you have to be careful not to tear yourself up on the studs. I wore gloves and still had a few scratches when I was done. I was impressed with how well they wear; I put about 80 miles on the set in snow, ice, rocks, mud and even a few unplanned miles on asphalt without a sign of wear, not even a rounded knob. Some of my rider friends get about three winters (November through April) out of the Trelleborgs. Remember, these guys are economically minded and take it easy when riding over roads and rocks-and rightfully so. At $259.95 for a front, $336.95 for an 18-inch rear and $359.95 for a 19-inch, you’ll want to get as much time out of the studs as you can, too!
@ Welker
I'll give you a bone to naw on Raced Cycle-Rama San Antonio, TX - 125MX & 1975 Omaha Moto Park Herman, NE
I had a couple of friends I was from Ohio Pa arrea then but knew and raced against Glen Johnson Houston and Mark Harrington Amarillo, TX
'
were some real bad asses LOL !
Interesting part I found in this article is that they said the soil in Atlanta is getting dried out from sitting around in the stadium. Hope they drag out a hose and wet that stuff down or we're going to be hearing the same complaints as the first six weeks. Dried out hard pack soil should not be an issue in Atlanta. Someone get on it!
Pretty good Pirelli ad.
One element lost in the whole traction/track break down is soil and dirt maintenance, and I'm not talking about getting out the water truck or skid steer.
In Weege's interview with Rich from DW he said the dirt for many of these SX tracks is the same dirt used every year, and it's usually "stored" piled up at a trucker's lot. The track dirt sounds neglected. Before it's put into "storage" each year they should mix in some manure or compost and add in a few hundred earth worms to the mix. The soil nutrients in manure and compost will be broken down and spread throughout by the worms, enriching the dirt. Improved track dirt would hold moisture better and not turn into the slick hard pack we're seeing lately.
If they've been using the same dirt for years, that explains why all the tracks are breaking down so bad.
@bd25 Ya I knew Clay Hoenshel and Cooper now Hawthorne is in OK Dennis had some hidden practice tracks that were pretty tough. also in the 70 I raced ecpert pro or "A" class in the midwest. Did ok. Moved to TX in 78. At first I was working 2 jobs so I raced in the intermieate 125's for a while, those 13 year olds were fast! I have some pretty good stories thogh. In 81 I started racing open Intermidiate when we still raced 8 laps. It was easy and did not have to work on the bike much. So I kinda cruised for a few years till I turned 30 then raced over 30 Expert. I did manage to win a race once in a while though.
I never got my Pro Liscense cause of some problems but raced a lot of big money outlaw races in the midwest and as far away as I could to try to make some money. Had a full time job since I was 15. did some Pro Am stuff also.
@ welker you ment Glock lol!
@ Glock26 (love the name...)
I'm from Amarillo & have known Mark Harrington (& his family) since I was 10. We were both sponsored by a local Suzuki dealership for a couple of years. Mark's about 7 years older than me.
If fact, I just talked to Mark on Monday. I founded a group (FOBA) a few years ago of guys & gals who rode & raced during the 70's & 80's.
https://www.facebook.com/pages/FOBA-2013/175368202506312?sk=wall
Without a doubt, Harrington had world-class speed. He finished 3rd @ the '73 125 World Cup GP in St. Louis on a BOX STOCK Penton 125. That man could absolutely...defy Physics on a scoot.
Yes, Dennis is up here now and has owned the over 30 and over 40 class,last few years. I think he turns 50 next year..Cooper turned 50 this year, joining Jorski, Thomas and Bridges making the old man class pretty fast...I can see I will still be mid pack, but with a smile on my face ..lol
Glock to bad you won't be in Wichita for the Arenacross this weekend. I am going up there to help a young new talent..could use your expertise...Be careful and enjoy Atlanta...maybe we can say howdy if I make St. Louis ...
This has to be the most civil message thread in the history of the website. I actually read all of them.
In the Willamette valley in Oregon, the IRC M5B reigns supreme for some reason. It is almost as good as a fresh trials tire, and if you take the extra time to stud it, loop outs are a real possibility even on the gorilla snot days. Obviously, the studs are verboten on the track, so keep that in mind. Something about the extra long knobs, and the relatively high durometer of the knob rubber mated with a softer sidewall beats most motocross tires, and we have done side by side tests. It is crazy how some old and dated designs work amazingly well in certain types of dirt. While front tires seem to be a point of debate, the IRC M5B is what all of us coast range hillbillys can agree on.
On the track, the M5B is soft and wallowy, but it does hook up, even when you wish it didn't. Using an 18" hoop with the wide version running 5-7lbs is stunning in the total gorp, while the 19" at 8-9lbs (120) is a good compromise between feel and traction if you are splitting your time between offroad and the track.
One caviat - the bike will turn better on a fresh one since the sidewalls break down quickly and the tire profile turns squarish. You can get more than a year out of a M5B with solid results, but when you finally swap it out, all of a sudden you feel like you can corner like a pro (which you cant, but it feels like it)
I am willing to bet that they are purposely adding ingredients to the soil to make it harder. If they wanted to, it is easy enough to add ingredients and churn the dirt up to make a softer base. It isn't all because the dirt is old and has been packed down by monster trucks. I think Feld wants tracks that don't rut up so that bigger jumps and rhythm sections can be used. They think big jumps are more exciting than great back and forth racing. Leave the crazy jumps for FMX where they still are even kinda boring these days.
Those Barum wedge tires sucked, I worked hard to find a way to make those things turn, thinking all those side knobs with such a huge contact patch when laid over would make for a sticky front end, but surprisingly on hardpack it washed out like a sand road in a tsunami. Felt like my front end was strapped to a four-wheeled dolly. I got best results from a Metzeler front tire and even the IRC Metzeler Replicas, which had a little bit harder rubber, same pattern, not quite as much traction but lasted twice as long.
few years ago we would ride with a couple guys that ran the Tera-Flex tires on CR500's, I learned not to follow, quickly!!