24 minute read
COVER STORY: YELLOW PERIL
By Kenny Roberts, Mitch Boehm and Patrick Bodden
It is without a doubt one of motorcycling’s most notorious and legendary happenings. And in the world of dirt track racing, America’s original contribution to world motorsport, it is undeniably the biggest, baddest story in the sport’s century-plus history.
It, of course, is “King Kenny” Roberts’ superhuman performance at the 1975 Indy Mile on the legendary Yamaha TZ750-powered dirt tracker, a motorcycle so powerful, so brutal and so potentially dangerous to human existence — not to mention Harley-Davidson’s all-conquering XR750 — that the AMA eventually banned it from competition.
YELLOW PERIL
The real story of Kenny Roberts, Yamaha’s TZ750 ’Miler and the 1975 Indy Mile
Photos by Dan Mahony
It’s an AMA Hall of Fame freight train, with TZ750mounted Kenny Roberts leading the XR750s of Corky Keener (62) and Steve Morehead (42). It’s a sight the Milwaukee contingent would see very little of, as the AMA banned the TZ at the end of the 1975 season.
The story of AMA Hall of Famer Roberts and the TZ750 dirt tracker at Indy is one of those culturalphenomenon tales that gets tossed around and regurgitated so often that it ends up taking on a life of its own. Everyone’s heard a version, but over time the facts lose their edge and the story gets muddled.
Luckily, there’s quite a bit more red meat here than simply the race reports, rememberances of folks that were there (or said they were), or Roberts’ oft-quoted quip after the race that, “They don’t pay me enough to ride that thing.” Which he meant quite seriously.
Many moons ago, back when print magazines ensured that motorcycle enthuiasts would get both good information and good writing about their sport (regardless of whether you liked a particular magazine’s angle or tone), I asked my friend and threetime 500cc world champion Kenny Roberts to write a series of articles about his life and career, and do so with racer, architect and Motorcyclist contributor Patrick Bodden — another old friend.
Kenny agreed, and the collaboration generated several year’s worth of insightful and insanely interesting features — 14 or 15 in all, I believe, and all from The Man himself — chronicling KR’s life, from childhood to retirement. Naturally, we called them the Roberts Chronicles, and they were a huge hit with Motorcyclist readers between 2003 and 2007.
The most popular piece by far, of course, was the one Roberts and Bodden wrote about the 1975 Indy Mile. No surprise, really, as that event, that particular motorcycle and Kenny’s performance on it that night has taken on
Built by joining a pair of TZ350 cylinders on a common crankcase, the TZ750 engine was a simple but brutally effective weapon, winning nine straight Daytona 200s between ’74 and ’82. Mated to a Champion frame, the brutality would continue.
mythic proportions over the decades.
Roberts’ take on that race and the motorcycle he used to stage what is perhaps the wildest, last-to-first victory in history is supremely interesting for a whole lot of reasons, not the least of which is the fact that it’s his take on what happened between him, Jay Springsteen and Corky Keener that night. Roberts, who was just 23 years old at the time (let that sink in for a minute), was the only person in the world on that motorcycle that evening, so his words and descriptions carry significant heft.
Between originally editing the piece for publication in 2004, proofing it several times during ship week and then re-reading it over the years for fun, I’ve probably read the Indy piece 25 times. And every time it generates goosbumps and awe. That’s the sign of a truly great story, and great stories are meant to be retold, reconsidered and re-enjoyed. And that’s why we’ve included it here, along with some commentary from Springer, Keener and Kenny himself.
Enjoy the time-capsule trip back to August of 1975, folks!
KENNY ROBERTS
— Mitch Boehm
The Race
Even today, people will walk up to me and say, “I was at the race” or “I was at the mile.” They don’t have to say anything more or explain what they mean. They know I’ll know exactly which race they’re talking about — the Indianapolis Mile in 1975 on the Yamaha TZ750-powered dirt track racer. To be honest, I hadn’t been exactly enthused at the idea of building this thing, this overpowered dirttrack miler that used a 750cc four-cylinder twostroke engine from a 170-mph Yamaha roadracer. For one thing, there were only a limited number of mile races on the AMA schedule. I wanted to retain the number 1 plate I’d won the previous season, and thought we — Yamaha — should build a proper dirt track racer, which meant building it around an engine designed for the job — not the XS650 production-based engine we’d been using. But Yamaha wasn’t going to do that. They didn’t disapprove of the TZ project, but they didn’t provide any real support, either. I guess you could say we were on our own, looking for a way we might be able to beat the Harleys, which did have proper dirt track engines and were constantly improving.
So at the time, I more or less said, “Go ahead and build it. I’ll ride it.”
The idea to build this TZ-powered ’tracker was actually Doug Schwerma’s. Doug was the owner of Champion Frames, which produced excellent dirt track racing frames, including some of those we had used on our XS650 racers. So Doug built the first TZ ’Miler for Rick Hocking. Hocking rode it at Ascot, which wasn’t an overwhelming success. But he demonstrated enough potential that several more were built: Terry Sage built one for Bud Aksland’s brother, Skip; Randy Cleek had one built; Yamaha Canada built one for Steve Baker. And Kel Carruthers built mine.
With a good 100 horsepower at the rear wheel there was no question the thing was going to be fast...on the straights, anyway. But all that fourcylinder, two-stroke roadracing power comes in with a big rush and it was going to be difficult for the rear wheel to put it to the ground. The bike was also fairly light, which only made the traction problems worse. Naturally, there was quite a bit of experimenting with tires, trying to find a combination that would work. At the time, the only good dirt track tires available to us were 4.0-inch x 19-inch Goodyear DT’s, which weren’t good enough for this bike. Eventually, we came up with a workable tire, 18-inch Goodyear roadracing tires with hand-cut treads. In fact, these tires worked so well that they became the basis for the tires that are used today. [True at the time, but things have evolved tire-wise on the professional circuit — Ed.]
As for modifications to the engine — to try to get the rear wheel to hook up in the turns — there weren’t any, really. I did have Kel fit a kill switch directly into the grip that would cut the ignition on the number-three cylinder. I would push it on going into the turns, and then let it off when I felt the time was right. Trouble is, there would then be an instantaneous extra 33 horsepower delivered to the rear wheel. Basically, regardless of what we tried, the thing just wanted to spin the rear tire everywhere and go sideways. When it did hook up it was fast — like 145-150 mph fast down the straights, a good 25 mph faster than the Harleys, maybe more!
The first time I ever even sat on the TZ750 dirt track racer was before practice for the Mile at Indy. Practice was exciting, to say the least. What became immediately clear to me was that someone was going to die riding such a bike...or cause someone else to die. I wasn’t interested in either option, so I spent practice trying to figure out how to come to grips with this situation. I was at the top of my game in those days, but I really had to wonder what I had gotten myself into.
The heat and semi races were no less exciting. When I managed to pass other riders going into a turn, they would often get past me coming out, and I had to ride like a madman down the straight to pass them back and put enough distance on them so that they couldn’t pass me again in the next turn. Basically, the TZ and I clawed our way to a 4th in the heat and in the semi we just barely transferred to the Main. Had I not figured out during the semi that I needed to shift up into 5th — instead of riding the entire track in 4th — I would never have made it to the Main. The big fun was about to begin. I would be starting from the last row and still didn’t really know how to get the bike around the track.
When the flag dropped for the Main the thing just about sat there, spinning the rear tire. I was dead last off the line. When I did finally get the bike launched I passed about 10 riders when I hit the straight for the first time. The next five laps were nothing but a blur. Even at the time I wouldn’t have been able to say exactly what I was doing. I was just riding on pure instinct.
As the field spread out things became a little less crazy. I could experiment with different techniques. For the next 15 laps, lap after lap, I worked at finding a way to get the TZ to hook up. How fast in, how fast out of the turns; precisely where to position myself just before the apex. Use the
KENNY ROBERTS
Roberts contemplates his mortality as a tech readies the TZ for battle, while Yamaha Canada’s Steve Baker (background) wonders about his chances aboard the ferocious two-stroke.
Roberts, surrounded and sideways on the spin-happy TZ750 ’Miler. Yamaha’s Kel Carruthers fit Kenny’s TZ with an ignition-cut switch (for one cylinder) to help the thing hook up, though when released, all 100-plus horsepower came alive in a rush.
kill switch, don’t use the kill switch; throttle position in each case. There were a lot of variables to get just right, and it required a lot more precision than you might think. Of course, the whole time, the tires were chunking, so there had to be a kind of conservative/aggressive approach to the whole deal and knowing when to be which, and under which circumstance.
No matter what, there was no way I could run in the same groove with the Harleys. I thought, “Different bike, different track.” So for lap after lap, I created my own track, building my own groove, pushing the dirt — the berm, the cushion — farther and farther out, making it bigger and more solid so I could get a decent drive off it. By then, I was way out there, far from the rest of the racing going on. When I say far, I mean far — all the way to the edge of the track. I was clipping the hay bales with the rear of the bike hard enough that the bike came in from the race with straw wedged into it and baling wire embedded in the exhaust pipes! Looking back on it, it was not the smartest thing I ever did. If I had ever seen Kenny Jr. or Kurtis doing such a thing, I would have tried to have the race stopped...or I would have just left so I wouldn’t have to watch something so crazy and dangerous.
Anyway, running my own race on my own track was paying off, and I finally settled into a pattern. But I had to hit every point on the track within 12 inches so that the bike was in the groove, working as well as possible, and turning the fastest possible lap times. Lap after lap, I was passing rider after rider and moving forward.
Eventually, I came up on Gary Scott and Mert Lawwill who were battling for third entering a turn. Keep in mind, because of all the extra power I had, I was closing in on them into the same turn going at least 25 mph faster. Lawwill decided he could take Scott on the outside and swings out to pass him. Holy shit! I can’t pass Scott on the inside, because he’s right on the guardrail. I can’t pass Lawwill on the outside, because...well, because I just can’t turn the thing. But Lawwill swings just wide enough that I make the pass between him and Scott, completely sideways with no room to
spare between all of us. I really had no choice in the matter and it was really a question of a split-second educated guess that turned out to be correct.
But just how many times was I going to get away with guesses? And how many times were other riders going to get away with them as more TZs showed up? Just picture it…six, seven or eight of these things mixing it up with the Harleys, but going 25-30 mph faster on the straights and going into the turns. A rider would have to guess right each and every time to avoid disaster. Pitching it into a turn at 150 mph, you’re not going to stop. These things didn’t have any brakes to speak of. You’re not going to turn, as it’s already sliding sideways to scrub off speed. If someone changes his line and moves into your path, that’s it; you’re just going to hit him at full speed. As it was, I was lucky I had fit between Lawwill and Scott when I blew by them.
Then there was me, by myself, with my own line at the edge of the track. Had I misjudged, jumped the berm and hit the hay bales, I would have cleared the concrete wall on the other side. No problem there; I would have just been pitched over the wall and into the catch fence designed to catch sprint cars, which meant it was heavy duty, which meant hitting it at speed would be like going through a cheese grater. And going through the narrow gap between the pairs of I-beam posts that held up the sections of fencing? Well, I think you can imagine. Like I said, the whole thing was a surefire recipe for disaster.
So far, I had avoided disaster…by inches in some cases.
Five laps from the end of the race I could finally see the leaders, Jay Springsteen and Corky Keener. They were racing each other down the straight, with Keener having the advantage on top speed. I started to think I hadn’t been riding my ass off and risking life and limb for nothing. It looked like I was going to get 3rd, and I wasn’t sure I could do any better than that. But it wasn’t over yet.
Going into the last turn, I closed right up on them. Coming out, I don’t know what happened, exactly. I shifted up into fifth and that thing got a drive like it had never gotten during the entire race. It was like God himself decided the TZ was going to get traction coming off that turn! I was doing my part, straining every muscle in my body as hard as I could to get the bike to hook up. When I nailed the throttle, the bike didn’t go sideways…it accelerated so hard and so straight that, for an instant, I thought I was going to hit Springsteen. But I didn’t, and just blasted past him, thinking, “Great, I’m gonna get second.” But I didn’t stop there. The next thing Keener saw was my yellow and black fuel tank, and he saw it too late. I mowed him down with that TZ750 racer and beat him to the finish line by inches.
The place went insane! I’ve never seen anything like it. Ever. It was complete chaos. The whole crowd was on its feet, everybody out of the bleachers, yelling and screaming and jumping around. Even people who weren’t there remember that race... and the comment I made afterward. I understood what had just taken place and I said, “They don’t pay me enough to ride that thing.” It was spectacular. But it was just too crazy...really, really dangerous. Even the AMA — an organization I didn’t often agree with — understood that. They knew that with more development the TZ750 dirt trackers would become missiles, and soon. And they understood that, even if they managed not to kill anybody in the process, they were for sure going to kill HarleyDavidson. The next year they were banned. You could say it was over before it ever got started.
Fine by me. Riding that TZ750 ’Miler was a hell of an experience, though, and I will always remember the race at Indy in 1975 as my most significant accomplishment on a dirt tracker. I’m just glad I lived to tell the story! — Kenny Roberts with Patrick Bodden
Springsteen and Keener were so involved in racing each other that they hadn’t noticed I was coming up. Until three laps from the end, which is when Springsteen heard something and looked back as I was closing in. I’m sure he must have looked back several times during the race and seen no one. This time was different. There I was, and coming up fast. Springsteen decided he had better signal Keener. So he pointed rearward with his thumb, then held up his finger to indicate number 1, which was me. Keener got it wrong. He assumed Springsteen was indicating that no one was behind them and that he was going to win the race since he had the faster bike. The two of them continued racing as they had been, Keener thinking he could relax a bit. Bad idea.
Jay Springsteen
The AFTERMATH
Roberts talks about the crowd going “insane” in the aftermath of his dramatic, come-from-behind victory, and from what I’ve heard from folks who were there (industry folks, primarily), he wasn’t wrong. Despite the fact that a lot of dirt track fans rooted for the Harley-Davidson factory and the many privateers that ran its superb XR750s, Roberts — who was the reigning Grand National Champ, after all — was a fan favorite on his yellow Yamahas.
The TZ750’s wicked, high-pitched wail didn’t hurt the energy level at the racetrack, either. Few aural experiences in motorcycling can match the sound of a TZ750 at full snarl through its expansion chambers and narrow stingers. There’s simply nothing like it, and it’s a prime reason folks went berserk in 2009 when Roberts was reunited with the TZ at Indy — and even did a couple of laps on it.
After the race and in the years that have followed, both Keener and Springsteen have commented on how the race went down from their perspectives.
“On the front straight we made a bit of a show of it,” Keener told an interviewer, “for the fans. Springer and I were messing around, pinching each other on the leg as we passed one another, that sort of thing, but we were racing hard and going for the win. When Roberts passed me at the flag I thought it was Jay at first. I was thinking, ‘Man, that’s a stubborn SOB… couldn’t even let me have this win!’ I didn’t know it was Roberts until I saw Jay pull up next to me.”
Still, Keener hasn’t let the oft-asked question of “how he let Kenny Roberts by at Indy?” get to him. “How many guys can say that even in a loss they are talked about that much?” Keener told journalist Scott Rousseau. “That’s one of the times where everybody remembers who got second!”
At his AMA Motorcycle Hall of Fame induction ceremony in De“I shifted up into fifth and that thing got a drive like it had never gotten during the entire race. It was like God himself decided the TZ was going to get traction coming off that turn!”
KENNY ROBERTS
As this Dan Mahony photo shows, Roberts’ best method for getting the TZ ’Miler around a Mile or Half-Mile oval at competitive speeds was to stay high, out in the loose stuff and up against the straw bales, maintaining momentum and hoping the rear Goodyear would hook up.
After his two-lap “demonstration” at the 2009 Indy Mile (where he looked more like a current competitor than a retired AMA Hall of Famer), Roberts celebrated with Valentino Rossi, Kel Carruthers, and announcer Scottie Duebler.
cember of 2018, Keener added this: “Kenny Roberts was on that scary four-cylinder thing at Indy…and I’d like to thank him for making me the best-known second-place finisher in history!” Nice.
Springsteen saw it this way in an interview from 2018. “Me and Corky [Keener] were going at it up front for the lead, and I remember looking back at one point and saw that we had a pretty good gap on [Roberts], but I was trying to tell Corky that number one — meaning Kenny — was coming.”
“We were going back and forth,” Springsteen continued, “and I didn’t see Kenny again until we crossed start-finish, and he was going 20 or 30 mph faster than we were! He was back there just far enough that we didn’t hear him. To this day, Corky says he never knew Roberts was back there. Corky and I were exchanging hand signals during the race, but Corky was probably thinking that we were just flipping each other off, which we did a lot in those days! [Laughs] I remember telling Kenny later that it was me who made him so famous that day!” — Mitch Boehm “I’m just hoping it’ll come back to me,” he said with a laugh as Carruthers and Edwards looked on humorously, “cuz if it don’t, there’ll be a yellow speck down in turn one, probably.”
KENNY ROBERTS
The reunion
Nearly 35 years after the fact at the 2009 Indy Mile, Yamaha helped reunite Roberts with the exact machine he rode on that amazing night back in 1975, which had been rebuilt and restored by the late racing historian, author and restoration guru Stephen Wright. It was one of those grand racing weekends, the crowd larger than usual thanks to the MotoGP circus happening at the Speedway, and several MotoGP heroes in attendance, including Valentino Rossi, Colin Edwards and AMA Motorcycle Hall of Famer Kel Carruthers.
“It’s pretty exciting being back here again,” Carruthers said during the evening’s festitivites. “I mean, I’ve been looking after [Roberts] since he was about 18 years of age. So we’ve been together a long time.”
Roberts, who was to do a couple of demonstration laps during opening ceremonies, had mixed feelings about the evening and the ride.
“I’m just hoping it’ll come back to me,” he said with a laugh as Carruthers and Edwards looked on humorously, “cuz if it don’t, there’ll be a yellow
When Roberts was re-inducted into the AMA Motorcycle Hall of Fame as a Legend in 2011, noted motorsports artist Tom Fritz was commissioned to paint something appropriate — which he did in just five days. Fritz’s painting of Roberts scattering straw at Indy is titled, appropriately, So Woefully Underpaid, prints of which are available from Fritz at fritzart.com, tom@ fritzart.com or by dialing 805.499.1639.
speck down in turn one, probably. I haven’t rode a motorcycle in a year,” he added, which caused Edwards to ask, “Really?” Roberts nodded, adding, “I’m either gonna make it or I ain’t gonna make it!”
Once darkness fell, Roberts suited up, climbed aboard the storied yellow beast and rolled out onto start-finish, revving the motor to the stops and sending that ear-splitting TZ750 shriek ricocheting off the grandstands — just as he’d done 34 years earlier.
What followed was pure, undistilled Kenny Leroy Roberts. America’s first world champion motorcycle racer pulled up to the start-finish, pinned the throttle and blasted off the line, the rear wheel spinning as it had in ’75 and the bike fishtailing luridly as he headed to turn one. Once there, Roberts pitched the thing into a big, nasty slide — without one bit of practice. There’s a reason the guy is a 3-time world champ. The crowd went nuts.
Immediately afterward, KR was clearly jacked up. “It came back to me!” he said just after pulling his helmet off. “I was a little bit nervous. Had my bone doctor on standby! [laughs] I didn’t practice before I rode it. I was going make a fool of myself, or make it look like I knew what I was doing. I wanted to go faster. It was almost like being there in ’75. Very moving for me. Very cool.”
“I’m thrilled to death that the people enjoyed it,” he said a bit later. “Cuz basically, that’s what we do all this stuff for anyway. I won world championships, was the first American to win a 500 Grand Prix title, and the only guy to do it first year out. But when you think about your best individual rides, and I’ve said this before, I’d have to say mine was the Indy Mile on the TZ750. The thing had not been raced before. The fans obviously didn’t
know what they were in for. I spent a couple of laps in last. Worked my way up. Kept going wide as it didn’t like the groove. Kept going higher and wider. During the last two laps the back wheel was just tapping the haybales. I thought I was gonna get third, and I got a drive, which I couldn’t believe. Two feet before the flag, I’m thinking, ‘I gonna win this thing!’ People were jumping out of the bleachers, the straightaway’s full of people screaming and yelling. And the quote about them not paying me enough? I meant it!”
I spoke to KR for this story, and he had this to say about looking back at what happened 46 years ago. “It’s still very cool,” he said, “to have folks come up to me and say, ‘Hey, I was at the mile.’ And we all know what that means. At the time, back in ’75, I didn’t think about it much. It was just another race. I put everything I had into that race, on every lap, just like always. But other than that unique motorcycle, it was just another race.”
Then I asked about the reunion in 2009. “It was great!” he said. “The modern Dunlop race tire hooked up so well that night, something that never happened back in ’75! I got off that thing and thought that if we’d been able to develop proper tires for that thing in ’76 and ’77 and develop the bike some more, we’d have won every Mile on the schedule. Harley would never have seen where we went!”
“It took a lot to win that night,” he added, “more than anyone realizes… pushing that cushion out, farther and farther every lap, being really precise, carrying momentum, all of it. It all came together. All my experience, and all that I learned from when I was 14 until 1975, was put into those 25 laps. It’s something that lives inside of me. It’s very special.”
Very special, indeed. — Mitch Boehm
