FOLKLORE: HONDA’ S DIRT TRACK RACERS
The most unlikely dirt track bike, and the one that won.
In the 1970s Harley Davidson had the American Grand National Championship sewn up. They were winning on Sunday and selling on Monday. Honda took note and wanted a piece of the action, much to the chagrin of the Milwaukee milers…
Between 1965 and 1981, U.S. motorcycle registrations increased from 1.4 million to six million. Honda got the lion’s share of that increase, but that growth was not dependent on racing success. That’s because American Honda didn’t have a concerted or comprehensive AMA racing program, although some of the company’s American employees ran ‘back-door’ racing teams. That was how Honda won their first-ever AMA dirt track race in 1974, at the season-opening short track held in the Houston Astrodome. Mike Gerald, known locally as the ‘Cajun King of Short Track’, rode an Xl350-powered single to the win in front of a huge crowd.
In the late ’70s Dennis Mckay, who controlled American Honda’s small racing budget, funded a back-door flat track team with bikes made by Jerry Grith, who had previously worked on Kenny Roberts’ Yamaha flat track bikes. Thanks to promotion from Camel cigarettes, the Grand National Championship figured on popular TV such as Wide World of Sports. American Honda had to admit that a #1 plate would be a marketing boon. That meant building a competitive flat-tracker. Harley-davidson had worked the bugs out of the XR750 over the previous decade, and shown that V-twin power was the way to go.
It made sense to tap Grith for that assignment. What didn’t make any sense at all was Honda’s decision to use its only existing V-twin, the new CX500, as the basis for a race motor. The porky water-cooled, shaft drive tourer was an unlikely starting point for a racer.
‘We knew we couldn’t compete with the Harleys… but Honda didn’t have a 750 twin, they only had fours. So that was all we had to work with,’ Grith once told me. ‘It was a sorry deal.’
Sorry or not, Honda gave Grith a CX500 motor. He turned it 90° in the frame and grafted on a sprocket, but with exhaust and inlet ports pointing outwards the rider’s leg had to go between the carburettors, and locating the radiator was tricky too. The CX500 was homologated for AMA competition in 1978.
It was at least 10mph down on top speed, and not really competitive at all, but Mr Irimajiri [the legendary HRC engineer who created the oval-piston NR500] came to the San Jose Mile in ’79 or ’80, watched it run and liked it so much he got his picture taken sitting on it.
With Irimajiri’s support and some assistance from Honda’s Racing Services division, Grith punched the CX500 out to 750cc, justifying the NS750 designation. He sorted out a chassis for the more powerful motor and got five frames made up at dirt track chassis specialists C&J. Grith hired Ted ‘Too Tall’ Boody and Hank Scott as development riders – both men had already won AMA Nationals and were destined for the AMA Hall of Fame. They worked some of the bugs out of the NS750 without attracting too much attention by racing a bunch of nonNational Miles between Kansas and Ohio.
As the project gained momentum Grith drafted aces: Gene Romero who’d already won the Grand National Championship in ’70; Mike Kidd who would win it in ’81; Terry Poovey, who helped develop the first monoshock
‘Griffith got one that he chopped and changed a bunch of stuff on. It shook like a dog shitting a peach stone, but it hooked up’
XR750 and Scott Pearson, a stalwart privateer. Most of their feedback was negative.
‘The problem wasn’t a lack of power. In the end, we got 90-92 horsepower out of it,’ Grith told me. ‘Its biggest problem was they’d bored it out so big it didn’t have enough room [in the water jacket] around the sleeves. It would get steam pockets in it, overheat and slow down. If we could’ve run anti-freeze it wouldn’t have boiled, but the rules specified water only (anti freeze messed up the dirt if it leaked out).
In the end Scott Pearson won one National on the NS750, in 1982. Admittedly it was a bit freakish, Grith attributing the win to Pearson’s holeshot ability and the Louisville track’s narrow groove, which Pearson was able to defend as the NS predictably lost power late in the race. ‘It was Scott Pearson who won the race,’ Grith told me, ‘not the motorcycle.’
The NS750’S overheating problem was unsolvable and Honda faced the fact that it wasn’t going to win without a new motor. For years, the story has circulated that Honda merely bought a Harley-davidson XR750 motor and reverse-engineered it to create the RS750. But that’s not what happened.
Honda were developing their first 750cc cruiser, the Shadow. It was a 45° V-twin with offset crankpins, three valves and two spark plugs per cylinder. And shaft final drive. The Japanese sent one of their 750cc prototype motors over to Grith to see if he could adapt it to flat track racing. He and Gene Romero immediately saw that although it had been designed as a full 750 it was too wide, the sump was too deep and, overall, it was too heavy to be useful. ‘We would be better off racing what we have,’ Romero told Grith.
The Yanks wangled a trip to Japan hoping they could convince Honda to create a purpose-built engine. Honda weren’t about to go that far but, in the spirit of always travelling hopefully, the two caught a glimpse of a secret project: a 750cc twin with a narrow V-angle that was being developed for the Paris-dakar race.
‘It had a two-valve head, but it was perfect,’ Grith recalled. ‘I said, “We need this one here, with a full-circle crank and a four-valve head.”’
That was the genesis of the RS750 that appeared in 1983. It was no XR750 clone – if it had been one it would have worked better right off the bat. The first few iterations didn’t exactly have Harley-davidson’s riders shaking in their steel shoes. Honda’s factory team practiced with new RS motors to develop them, but raced with the old NS ones which, for all their overheating, were still faster. Honda sent one RS750 prototype after another over to Grith that first season. He tried them, modified them, and sent them back. Finally, Grith got one that he chopped and changed a bunch of stuff on. It shook like a dog shitting a peach stone, but it hooked up and Hank Scott won the Du Quoin Mile on it. Grith immediately crated the mill and flew it back to Japan with the request – more like this, please.
‘They copied that one and sent a bunch back to us.’ Grith laughed, as he recalled it. ‘They were firebreathing sumbitches. Once we’d worked the bugs out the RS annihilated the Harleys.’
At that point – Honda being Honda – someone high up told Grith it was time to go and win the Grand National Championship. He then had to point out that there were three Harley-davidson riders they still could not beat over a full season. The three riders were: Scotty Parker; Ricky Graham and Bubba Shobert.
‘We couldn’t get Scotty, but we got Ricky and Bubba,’ Grith told me. ‘I will never forget the day we went to the Sacramento Mile with Ricky and Bubba. Down the back straight, they were gone. I thought the fans aren’t going to like this.’
And the fans weren’t the only ones who weren’t keen – as far as Harley-davidson were concerned, that ‘RS’ stood for ‘Restrict it!’
Ricky Graham won the Grand National Championship on an RS in 1984 and Bubba Shobert took over and won in ’85, ’86 and ’87 before making the transition to road racing. After the 1986 season the AMA introduced new rules requiring the Hondas and Harleys to use a 33mm restrictor plate in each inlet tract. The AMA presented this change as a way to increase reliability and control costs because tuners would have to do fewer engine rebuilds. But, the real reason was that restrictor plates would slow Honda’s RS750 more than Harley-davidson’s XR750.
Honda felt unfairly penalised, but anger at the rules committee was not the only reason they disbanded their factory flat track team. The mid-’80s was a particularly challenging period for Japanese manufacturers, and Harley-davidson had successfully lobbied for tariff protection. Honda sales were contracting and unsold inventory crowded dealer floors, which is never a good thing; the Shadow, which was presumably the model Honda wanted to promote with its flat track program, failed to meet sales projections.
Despite being hamstrung by the restrictor plates the RS750 remained popular with privateers who liked them because motors were delivered fully assembled and ready to bolt into a frame – conversely Harley-davidson’s XRS arrived as a collection of disassembled and barely finished parts. And, the Hondas had much longer service intervals – many privateers only rebuilt them once a season, whereas the XRS needed almost weekly attention. Ricky Graham won the RS750’S last championship, as a privateer, in 1993.
‘They were fire-breathing sumbitches. Once we’d worked the bugs out the RS annihilated the Harleys’