The Indy Curb: Road Course Can Run In Both Directions

MotoGP 2014 Indy

Elbow skimming the new curbing, Marc Marquez leads Andrea Dovizioso last year at Indianapolis Motor Speedway. The Honda rider won, while the Ducati pilot was seventh.

Last year, I wrote a story for CycleWorld.com about new curbing installed at Indianapolis Motor Speedway. The bi-directional design was used initially in May, 2014, for the inaugural Grand Prix of Indianapolis IndyCar race and, later, in August, for the Red Bull Indianapolis GP. The road course portion of the 16-turn track was repaved, as well.

After the MotoGP race, I asked Yamaha factory MotoGP rider Jorge Lorenzo, who finished second, for his take on the changes. “Compared to the previous track,” he said, “it has more consistent grip, there is no change of tarmac, and most of the bumps disappeared.” Because MotoAmerica is making its first appearance at IMS, I thought it appropriate to re-post this story for the benefit of competitors, some of whom raced on the previous configuration, and fans alike.

When MotoGP invades Indianapolis Motor Speedway August 8‑10 for the seventh annual Red Bull Indianapolis Grand Prix, Round 10 of the 2014 FIM Road Racing World Championship, riders in the three GP classes—MotoGP, Moto2, and Moto3—plus the AMA Pro Vance & Hines Harley-Davidson series, will find three significant changes: 1) a new 92-foot-tall scoring pylon with greater functionality; 2) a mildly reconfigured and completely repaved 2.591-mile road course promising consistent grip through all 16 turns; and 3) bi-directional permanent concrete curbs.

To learn more about these modifications—the unique curbs, in particular—I phoned Kevin Forbes, director of engineering at IMS, who designed the original 13-turn, 2.605-mile Formula 1 circuit (the Speedway hosted F1 from 2000 to 2007). “When we redesigned this course last fall,” he said, “we were doing two things at the same time: We were completely reconstructing the MotoGP road course, and we were creating a road course for Indycar.”

Historically, road courses are one direction, but when Forbes and his crew began work last fall, plans called for May’s inaugural Grand Prix of Indianapolis to run clockwise like F1. MotoGP, meanwhile, would continue to run counterclockwise—same as the oval-only Indianapolis 500 and Brickyard 400. “Every time you say one is clockwise and one is counterclockwise,” he said, “the curbs are automatically bi-directional.”

Further complicating the situation, the FIM changed its spec for curbs. “Used to be the entry and apex curbs were smooth,” Forbes said, “and the exit curbs were serrated. Smooth curbs are easy to deal with and maintain, and you can put them in quickly. Serrated curbs are a lot more difficult.” Now entry and exit curbs are supposed to be the same.

Indy Curb 2

New curbing, fresh pavement: Work done last year at IMS greatly improved rider opinion of the 16-turn road course.

When he realized IMS was ultimately going to have to redo all of its curbs, Forbes cringed. “We’ve got 12,000 feet of serrated curb to put in,” he said, “and it’s not easy to do.’” For MotoGP, IMS also employs temporary metal curbs between turns 4 and 5, and at the exit of turn 16.

Before new concrete curbs could be installed, several bends had to be reworked and new asphalt laid down, a $6 million bid to eliminate riders’ greatest concern: an inconsistent racing surface. While reigning series champ Marc Marquez said last year he “enjoyed” the bumpy, slippery pavement, Casey Stoner was openly critical of the track. “I’m not going to beat around the bush and say something is great when it isn’t,” the Australian said in 2011. “This facility could be unbelievable, with the history and everything.”

Forbes acknowledged the problem. “Not only did we have multiple surfaces,” he said, “but we didn’t have confidence in that old surface. The front stretch was one texture. Turns 1 through 4 were a different texture, and then between 4 and 5 was a different texture. Five through 16 was yet a different texture. Now, it’s basically two: the front stretch and everything else. That’s going to be one change the riders are really going to enjoy.”

Paving was completed last fall, but new curbs—1,000 cubic yards of concrete—couldn’t be poured until earlier this year, after what Forbes called “the worst winter in Indianapolis history.” Knowing his team was going to have an extremely short window for the installation, Forbes devised a plan. “We built forms inside a warehouse and practiced,” he said, “so when the weather broke, we could hit the ground running.

“We figured that out in February when there was 16 inches of snow on the ground and the temperature was 10 below zero. We had to have 200 feet of curb every day. That includes weekends. And the very first day we had a section ready, we formed and poured 500 feet of curb. We thought the curbs would delay the project, but we finished three weeks ahead of schedule. The work we did in the winter really paid off.”

Indy Curb

Another view of the Indy Curb, unique for its bi-directional design. The 10-level Pagoda in the background is centered at start/finish.

Forbes applied what he’d learned from his F1 experience, as well as work he’s done for other tracks during his 23-year tenure at IMS. “With Formula 1,” he said, “we tried to place the concrete curbs against the asphalt—the rough, uneven edge produced by the paving operation. This time, we over-paved the width of the circuit by about six inches. Wherever the curbs actually touched the track surface, which is everywhere, we sawed six inches off that asphalt. So there is a perfect, clean vertical edge that we placed the concrete against. We dug down about 14 inches and placed seven inches of crushed stone and seven inches of concrete. Where they meet the track, the curbs are perfectly even.

“Over the three-and-a-half-foot width, they gradually form this up-and-down serrated shape. So at the outside edge of the curb, where the form was placed, we laser-cut steel forms with that exact shape. We put the concrete in and shaped the concrete to that steel edge. Even though it was handwork, we had a precise guide, so the resulting shape matched that laser-cut edge.”

A full-scale mockup of the new curb was built in Europe to make sure the design was acceptable. “We spent a great deal of time with FIM Safety Officer Franco Uncini and other rider delegates,” Forbes said. “So even though they haven’t ridden on it, this curb is not a stranger to them.”

Forbes is pleased with his team’s latest work. “I designed the original Formula 1 circuit,” he said. “I redesigned it for MotoGP, and now, I’ve redesigned it a third time. I think we finally got it right this time.”

MotoGP 2014 Indy

Elbow skimming the new curbing, Marc Marquez leads Andrea Dovizioso last year at Indianapolis Motor Speedway. The Honda rider won, while the Ducati pilot was seventh.

Last year, I wrote a story for CycleWorld.com about new curbing installed at Indianapolis Motor Speedway. The bi-directional design was used initially in May, 2014, for the inaugural Grand Prix of Indianapolis IndyCar race and, later, in August, for the Red Bull Indianapolis GP. The road course portion of the 16-turn track was repaved, as well.

After the MotoGP race, I asked Yamaha factory MotoGP rider Jorge Lorenzo, who finished second, for his take on the changes. “Compared to the previous track,” he said, “it has more consistent grip, there is no change of tarmac, and most of the bumps disappeared.” Because MotoAmerica is making its first appearance at IMS, I thought it appropriate to re-post this story for the benefit of competitors, some of whom raced on the previous configuration, and fans alike.

When MotoGP invades Indianapolis Motor Speedway August 8‑10 for the seventh annual Red Bull Indianapolis Grand Prix, Round 10 of the 2014 FIM Road Racing World Championship, riders in the three GP classes—MotoGP, Moto2, and Moto3—plus the AMA Pro Vance & Hines Harley-Davidson series, will find three significant changes: 1) a new 92-foot-tall scoring pylon with greater functionality; 2) a mildly reconfigured and completely repaved 2.591-mile road course promising consistent grip through all 16 turns; and 3) bi-directional permanent concrete curbs.

To learn more about these modifications—the unique curbs, in particular—I phoned Kevin Forbes, director of engineering at IMS, who designed the original 13-turn, 2.605-mile Formula 1 circuit (the Speedway hosted F1 from 2000 to 2007). “When we redesigned this course last fall,” he said, “we were doing two things at the same time: We were completely reconstructing the MotoGP road course, and we were creating a road course for Indycar.”

Historically, road courses are one direction, but when Forbes and his crew began work last fall, plans called for May’s inaugural Grand Prix of Indianapolis to run clockwise like F1. MotoGP, meanwhile, would continue to run counterclockwise—same as the oval-only Indianapolis 500 and Brickyard 400. “Every time you say one is clockwise and one is counterclockwise,” he said, “the curbs are automatically bi-directional.”

Further complicating the situation, the FIM changed its spec for curbs. “Used to be the entry and apex curbs were smooth,” Forbes said, “and the exit curbs were serrated. Smooth curbs are easy to deal with and maintain, and you can put them in quickly. Serrated curbs are a lot more difficult.” Now entry and exit curbs are supposed to be the same.

Indy Curb 2

New curbing, fresh pavement: Work done last year at IMS greatly improved rider opinion of the 16-turn road course.

When he realized IMS was ultimately going to have to redo all of its curbs, Forbes cringed. “We’ve got 12,000 feet of serrated curb to put in,” he said, “and it’s not easy to do.’” For MotoGP, IMS also employs temporary metal curbs between turns 4 and 5, and at the exit of turn 16.

Before new concrete curbs could be installed, several bends had to be reworked and new asphalt laid down, a $6 million bid to eliminate riders’ greatest concern: an inconsistent racing surface. While reigning series champ Marc Marquez said last year he “enjoyed” the bumpy, slippery pavement, Casey Stoner was openly critical of the track. “I’m not going to beat around the bush and say something is great when it isn’t,” the Australian said in 2011. “This facility could be unbelievable, with the history and everything.”

Forbes acknowledged the problem. “Not only did we have multiple surfaces,” he said, “but we didn’t have confidence in that old surface. The front stretch was one texture. Turns 1 through 4 were a different texture, and then between 4 and 5 was a different texture. Five through 16 was yet a different texture. Now, it’s basically two: the front stretch and everything else. That’s going to be one change the riders are really going to enjoy.”

Paving was completed last fall, but new curbs—1,000 cubic yards of concrete—couldn’t be poured until earlier this year, after what Forbes called “the worst winter in Indianapolis history.” Knowing his team was going to have an extremely short window for the installation, Forbes devised a plan. “We built forms inside a warehouse and practiced,” he said, “so when the weather broke, we could hit the ground running.

“We figured that out in February when there was 16 inches of snow on the ground and the temperature was 10 below zero. We had to have 200 feet of curb every day. That includes weekends. And the very first day we had a section ready, we formed and poured 500 feet of curb. We thought the curbs would delay the project, but we finished three weeks ahead of schedule. The work we did in the winter really paid off.”

Indy Curb

Another view of the Indy Curb, unique for its bi-directional design. The 10-level Pagoda in the background is centered at start/finish.

Forbes applied what he’d learned from his F1 experience, as well as work he’s done for other tracks during his 23-year tenure at IMS. “With Formula 1,” he said, “we tried to place the concrete curbs against the asphalt—the rough, uneven edge produced by the paving operation. This time, we over-paved the width of the circuit by about six inches. Wherever the curbs actually touched the track surface, which is everywhere, we sawed six inches off that asphalt. So there is a perfect, clean vertical edge that we placed the concrete against. We dug down about 14 inches and placed seven inches of crushed stone and seven inches of concrete. Where they meet the track, the curbs are perfectly even.

“Over the three-and-a-half-foot width, they gradually form this up-and-down serrated shape. So at the outside edge of the curb, where the form was placed, we laser-cut steel forms with that exact shape. We put the concrete in and shaped the concrete to that steel edge. Even though it was handwork, we had a precise guide, so the resulting shape matched that laser-cut edge.”

A full-scale mockup of the new curb was built in Europe to make sure the design was acceptable. “We spent a great deal of time with FIM Safety Officer Franco Uncini and other rider delegates,” Forbes said. “So even though they haven’t ridden on it, this curb is not a stranger to them.”

Forbes is pleased with his team’s latest work. “I designed the original Formula 1 circuit,” he said. “I redesigned it for MotoGP, and now, I’ve redesigned it a third time. I think we finally got it right this time.”