INDIANAPOLIS -- The earliest ones, the ones made of canvas and later of pressed paper that are on display in the Speedway Museum, take your breath with their flimsiness.
But in 1911, when Ray Harroun was tooling around the Indianapolis Motor Speedway at 74.6 mph, no one was very worried about how the head gear worked.
All Harroun and company wanted was something to keep their hair out of their faces.
It wasn't until 1935 that helmets were considered mandatory equipment.
Now, as Al Unser Jr. and his peers whip around this same 2.5-mile oval at average speeds of 228.001 mph, the helmets are artistically stunning, in their slickness and color designs.
And they are technically revolutionary in their aerodynamic safety designs.
Bell was the first manufacturer with the latest changes, introducing its "Feuling SS", which created enough down force to hold a driver's head steady.
The front of the helmet came down below the chin and curved out slightly, like a lip or a duck bill, and served the same purpose as a car's front wing, creating downward force on the helmet.
A thin strip of rubber around the crown, called a wicker, acted like a rear wing, creating more downward pressure while redirecting the air over the rear of the car, instead of down behind the driver's head.
"They simply stabilized the helmet in the car," said Rick Mears, a four-time winner here who has no problem remembering how his head bounced around during a race. "Whether you are driving 35 mph, 65 mph or 220 mph, the farther ahead you can look, the better off you are. Now, guys can see clearly where they're going."
Arai Helmets introduced "winglets" on the side of Nigel Mansell's helmet during testing at Phoenix last January.
Two weeks ago, here at Indy, Simpson Helmets introduced its latest design, a helmet with an outer, fly-away shell that maintains the integrity of the inner helmet.
It is much the same concept used in the car design. On impact, the race car flies apart, but the tub, in which the driver sits, remains undamaged.
The new helmets weigh about 3 1/2 pounds, but the redesign adds 10 to 12 pounds of downward force during races to make them unshakable.
One of the biggest problems drivers had faced at high speeds was the continual buffeting of their heads.
"There you were driving over 200 miles an hour, and you can't hold your head still," said Robby Gordon, who drives the Valvoline Lola/Ford. "I felt like someone was straddling my car and trying to pull me out of it by my helmet.
"You want to know how good this helmet is? Well, I picked up 1 1/2 miles an hour the first time I wore it. My head never moved all the way around the track."
Before Bell, in 1955, and Simpson, in 1974, began making helmets, Hal Minyard and his friend Johnny McMurray made history in 1952 when they invented the McHal helmet.
In those days, most of the fatal injuries in motor racing were temple- and basilar skull-related. "The Hats" the drivers wore were made of plastic and looked like the bowl used to give Prince Valiant haircuts.
"It took us four months before we came up with a hat that worked," said Minyard, who at 69 is out of the helmet business, but still works for the Speedway.
"I wanted to make one just for myself, something that would come down around the side of the head and low across the back of the head. When I wore it for the first time at a midget race at Phoenix, everyone wanted one.
"It was the first full coverage helmet."
A.J. Foyt wore a McHal in 1964, when he won the second of his four 500s.
Minyard smiles at the memory and explains one of the nice things about his helmets was that they could be resized to better fit the drivers.
"Some guys had narrow faces, others were wider," Minyard said. "We could put the helmet in the oven in the track cafeteria, warm it up and either stretch it wider or make it smaller.
"I remember in 1965, when A.J. came back to the track, he'd put on some weight and we had to warm it up and stretch it out."
By 1967, all 33 drivers in the Indianapolis 500 field wore McHals.
Sunday, there will be three kinds of helmets in the field: Simpson, Bell and Arai.
Four drivers -- Nigel Mansell, Jacques Villeneuve, Hideshi Matsuda and Hiro Matsushita -- wear Arai.
Gordon will wear the newest Simpson, and eight others will wear a similar style, minus the fly-away parts.
The other 20 drivers in the field will wear Bell editions.