Sunday 15 November 2009

Kenny Roberts Yamaha TZ 750

I found these pictures on the web at the website.
The pics were taken by Mike Studzinski at the AHRMA vintage races at Sears Point in May 2000.

Here is a version of the Kenny Roberts story I pasted from the jj
By Eric Johnson

Motorcycle racing is full of myth, folklore and larger than life legends. However, in the eyes of plenty, one of the greatest stories ever told took place in the summer of 1975 on a mile-long dirt oval in Indianapolis, Indiana.
That year, Kenny Roberts was dong his best to beat back a number of beastly Harley-Davidsons that were trying to steal away his Grand National number one plate. Far more powerful, the Harley XRs were
omnipotent and all seemed lost. Or was it? Before the race scheduled for the Indy Fairgrounds, Roberts and his mechanic took a huge gamble and shoehorned an engine far too powerful and potent for the bike into the spindly frame of his Champion Yamaha 750. When his mechanic asked him how fast he needed to go to win, Roberts replied, "About one thirty should be enough.”
The 25-mile main event all came down to the final white flag lap. Having come from far behind, Roberts astride an evil-handling, ill- tempered motorcycle had taken huge chances and rode with extraordinary courage to reel in the two leading Harley-Davidsons of teammates Jay Springsteen and Korky Keener. With just three turns to go, Roberts rode the rim, pinned the throttle to the stops and was actually skimming the concrete retaining wall and skipping off hay bales.
"I still remember seeing hay scattering in the air as Kenny came out
of turn four,” reflected Robert’s’ mechanic of that night.
Roberts refused to lose and at the finish line, won the race by two feet. When he caught his breath and his hands stopped shaking, he uttered the words, "They don't pay me enough to ride that thing.”

A recent contributor to the discussion on the jj added some interesting insight to this. A person who was actually there.
Here it is
I lucked out and ended up at Indy that Saturday night. You could actually see a puff from the back wheel of Roberts' bike on the last turn. Because we were higher in the stands we couldn't clearly see the finish line, we could see the rest of the track though. We thought Roberts got second - which was incredible in itself.

The shame of the "legend" is that it leaves out the fact that there were four other TZs and three or four H2 Kawasakis, a few from Irv Kanemoto, with all of them pitting together in a general area. Only Aksland and Roberts did ok on the TZs and Don Castro ran second (I think) in the Trophy Dash (consolation for non-qualifiers), passing two Harleys on the straights and being repassed on the turns. Castro never quite figured out the line as Roberts did.

The other shame is that the story ignores the story of WHY and HOW for the Champion TZ. This story is told in the January 1976 Cycle World article (have it right here at hand) about and test ride of the Champion TZ750 mile bike. D. Randy Riggs rode Steve Baker's bike and wrote the article. Riggs and Baker (the first World GP champion from the U.S. in the 750 class) felt the ban was premature and not well thought out, that the bike had incredible power, but power to be respected and controlled. It wasn't the uncontrollable bike that the later legend made it out to be... otherwise Roberts probably wouldn't have ridden it again at Indy in 09.

The key points from Schwerma's opinion, were the good dependability and safety record of the TZ in roadracing and that many privateer AMA Grand National circuit riders had them. He saw the potential for a rider to have a reasonably competitive mile bike for the cost of adding a rolling chassis to their stable rather than a whole bike. After all the AMA GN points payout included roadracing, mile, half mile, short track, and TT racing and a privateer needed to get as many points and make a living.

Yamaha ignored the late Doug Schwerma's rerquest for a bike to use, even the offer to buy the bike and do all the work. He obviously eventually got one and built SIX chassis. They went to Roberts, Skip Aksland, Randy Cleek, Steve Baker, and Rick Hocking. He built the bike to use as much of the roadrace gear as possible, with the consideration of the privateer AMA grand national rider at the center of thought. The stock pipes, radiators, temp gage, and electrics came off the roadracer and on to the rolling mile chassis. The bike had been tested on half miles by Hocking, but the engines had never really had any sort of tuning mods for ridability, which could have boded well. Kind of a shame.

That ban took out EVERY multi-cylinder engine with 3 or more cylinders. It took out the H2 Kawasaki, the Suzuki GT750 (Ronnie Rall ran one), the Triumph/BSA triple, and any future 3/4 cylinders from ALL competition. Even now there is a bit of its effects on racing. You poor flat track enthusiasts out there don't ever get to hear the wonderous sound of the Tridents or any of the two strokes even on the Vintage circuit. The AHRMA didn't allow any 3/4 cylinder engines either. The closest I've heard was Rick Hocking on the TD2 at Ashland several years back - incredible. The sounds of Indy that night signaled the end of an era of development of new sources of power, ushering in the XR750 domination for the next 35 plus years. (Of course there was the RS750, but the AMA screwed it up adequately to quash it too. Heaven forbid the breed be improved.) The excitement was greatly diminished for me.

I guess you can tell I really liked what I saw that night and not so much the single brand racing that resulted from the ruling. Because Roberts was such a competitor, he ran the bike to the limits to win at almost all costs. Also because of that and his comments another dozen or so riders were denied the ability to have a reasonable ride in their pursuit of the AMA GN title after the ban. The fact that no one was injured or killed in the testing and racing of the TZ750s or the H2s kind of speaks volumes about the validity of the claims of those opponents along with the skills and talents of the racers who rode them. You'd have thought these bikes were going to be put in the hands of some squid stunter the way it sounded.


  1. I did, in fact, ride Steve Baker's TZ on the Corona, Calif. half-mile, a hard blue-groove surface that was not the ideal place for this motorcycle. But in typical Champion frame fashion, the bike handled beautifully, was predictable and it's an experience I will never forget. I was extremely disappointed when they outlawed these machines because I feel with time, the tuning could have been modified and racing would have been far more exciting than the Harley parade that was taking place.
    Doug Schwerma was a genius in his craft and I miss him to this day.

  2. Thanks for the informative comment. Cheers

  3. The bike next to the TZ750 is just as interesting. It's a TZ 350G engine in a modified Champion frame, built in the early '80s by Ray Abrams of A&A racing. It was a Harley-Killer on the mile as soon as it was built. Unfortunately it too was banned for being too "exotic". And in fact the "G" engine was almost impossible to get in the US -- the original in this bike came from KR himself.

    Everybody knows about the overpowered 750. But the 350 was a successful bike and in some ways more interesting, since it was less powerful than the Harleys, also lighter, and fully competitive. A&A retrieved and restored this bike in the last few years. A&A also built the 750 that KR rode last year. Rochelle at A&A says that both the 750 and the 350 had such abrupt powerbands that they required the rider to have the engine already "on the pipe" at mid-corner in order to get a drive on the exit. The difference was apparently that the toggle-switch power of the 350 would win the race, whereas the toggle-switch power of the 750 made keeping the bike on the correct side of the fence a heroic trial.

  4. Exellent information, Thank You. Great to hear about the 350 In the background.

  5. Don't forget the great 450 Honda twin that was featured in Cycle World as a legitimate Ascot weapon. I hated Hondas on the road at that time because they looked Japanese but this 450 was damn cool.

    Jupiter Wheels builder, CO Dave