Indy 500 drivers voice tyre concerns after vibrations, cording in practice

As teams have been aggressive in chasing performance, running cars with high degrees of camber, issues have arisen with blistering seen on tyres removed from some cars, with drivers complaining of vibrations and cording of the rubber.

The compound used by Firestone is essentially the same as used last year, although the tyres now incorporate a synthetic rubber created with recycled butadiene, a monomer produced with recycled post-consumer plastic waste.

“I think it's just because the left sides are softer,” said Team Penske’s Will Power after practice this week. “They just degrade easier. I haven't had a set without a vibration yet. I've had a couple that have been massive and you have to pit.

“It's left-side, left-front [or] left-rear. Depends which slides more. If you get an early one, it’s like almost to the point where you can't drive it. If it's a left-rear, you get that early, have a big moment early, you're going to be pitting on about lap 18 I feel like. You might be able to hold on for a couple more, but it's on the edge.

“I think it makes for better racing - it needed some deg. On a good hot day, I think it'll be a good race. Colder day would be pretty tight.”

Conor Daly, Ed Carpenter Racing Chevrolet

Photo by: Jake Galstad / Motorsport Images

The weather forecast at Indianapolis on Sunday is for temperatures in the 24-26C range during race time.

Ed Carpenter Racing’s Conor Daly, who needs to fight his way through the field from 16^th on the grid, is focused on gaining places at the end of a long run.

“The end of the stints could be the most important, I think some people really struggling with the tyres,” said Daly.

“I’ve seen cords on the tyres for some teams, I’ve had several vibrations myself, even one of the McLarens were cording and blistering a set in four laps of qualifying.

“I think some interesting stuff will go on with tyre wear, that’s what I’m most interested in for the race.

“If we can be consistent and take advantage of those last five to eight laps on stints, and when you get the chance to take tyres, I think everyone will take them.

“With the extra downforce, and extra load, maybe with the high-grip surface we have here. It’s not an issue with Firestone, but making these cars faster means more load on the tyres.”

When asked by Autosport about his tyre deg situation, 2019 winner Simon Pagenaud said: “I think that’s our strength. I think my qually run was the most consistent in the paddock and, while we didn’t have the first-lap speed, my car was the only one that was consistent across the four laps, so we can do it.

“To be on top of the tyres, this could be my game on Sunday. Hopefully it stays green and we have long stints, and I can use it to my advantage. When it gets hot, the downforce goes away, tyres get hot and nightmares can start for a lot of people!”