Lawson’s first few outings on the 1989 NSR suggested the paddock was right. Yamaha’s 1984, 1986 and 1988 world champion broke a wrist in pre-season testing and had another big crash at the second race. After two rounds he was behind Wayne Rainey (Lucky Strike Yamaha) and Gardner (factory Rothmans Honda) on points, his title slipping away.

Meanwhile grand prix rookie Mick Doohan, signed to partner Gardner in the number-one factory Rothmans Honda squad, was in even deeper trouble.

“The ’89 NSR wasn’t a good thing, that’s for sure,” recalls Doohan. “The first time I met Eddie he told me a lot of people can go fast on a 500 straight away. Then they have one crash, two crashes, three crashes and they take a big backward step. I’ve never heard a truer word. My confidence had been knocked about and I actually feared hopping on the motorcycle.”

Doohan and Lawson became friends, the rookie often confiding in the master.

“I remember Mick coming into my motorhome in ’89, going, ‘What do I do?’. He was practically in tears,” recalls Lawson.

Doohan did indeed have a horrific rookie 500 season, mangling himself in several grisly accidents. One journalist, concerned for his safety, nicknamed him “Dead by June Doohan”. Gardner’s year was also blighted by injury: a broken leg at Laguna Seca, which had him miss a third of the races.

Their problems forced HRC to direct its resources towards Lawson and Kanemoto, so although Lawson eventually became the championship’s fourth independent-team champion (after ‘King’ Kenny Roberts, Marco Lucchinelli and Framco Uncini), he ended up with better bikes.

Lawson and his pitlane guru stumbled on the first solution to the NSR’s problems during practice for round three, the US GP.

“Right from the beginning, Eddie’s comments were that the bike doesn’t turn,” says Kanemoto, who had already won three world titles with Spencer. “It wasn’t until the third race at Laguna Seca that I was able to relate what he was saying and what was happening.

“I walked down to the last corner [Turn 11], thinking maybe I could see why this thing isn’t turning well. I saw Eddie coming into the Turn 10 right-hander and I couldn’t believe it: when he turned in the bike wanted to go into the dirt on the inside, so he lifted the bike up, then when he turned in again he was way wide!

“I said to Toshi [Yamamoto, Kanemoto’s HRC engineer], it’s unbelievable, the bike is turning too quick! This was last practice on Saturday, so I said, get all the data from when we started testing, we’re going to look at it and then we’re going to make a change.

“I said, ‘This is what we should do, we’ll slow down the steering, but we better just go halfway because it’s such an extreme change from what we’ve been running’.

“The next morning Eddie came back into the pits during warm-up and I thought, ‘What are we going to do now, because we’ve probably gone the wrong way and made the bike even worse’. Eddie stopped in pit-lane and said, ‘This is the first time it feels like a motorcycle’.”

Next time out at Jerez, Lawson won his first race on the NSR, narrowing the points gap to leader Wayne Rainey. Then new parts started arriving from HRC and elsewhere at an astonishing rate, because HRC already knew that Gardner and Doohan weren’t going to be in the title fight.

The upgrades were mostly chassis parts: frames, swingarms, carbon-fibre handlebars and carbon-fibre wheels, plus AP Lockheed carbon brakes and Showa upside-down forks, both radical new tech at the time.

During 1988 HRC had reduced frame rigidity to improve grip and cornering performance, but they’d gone too far. At Jerez a revised frame arrived with extra bracing and a crossbar between the main spars, which had been removed in 1988. Also new were stiffer Showa upside-down forks.

But the bike still wasn’t right, so Rainey beat Lawson at three of the next four races, his Dunlop-equipped Yamaha YZR500 easier to take to the limit than Lawson’s Michelin-equipped NSR.

Kanemoto – who spent his first years in Second World War internment camps with 120,000 other Japanese Americans – remembers at least seven chassis during the 15-race season; so a new chassis every two races.

“We were trying to find a direction, just gathering more data, trying to make the bike more rigid, because a lot of the problem was that the bike wasn’t reacting quick enough to Eddie’s inputs,” he explains. “It was already understood that you could make the bike work better on its side by reducing the stiffness, but reducing rigidity in all directions makes the bike slow to react, so some of the frame stiffening did work.

HRC engineers were working towards their first understanding of tuned flex, which is still a crucial area in MotoGP chassis design. They were going too soft, then too rigid, gradually getting closer to the ideal combination of torsional and longitudinal flex.

“We were doing so much testing and trying so many things, so they started to understand what needed to be done next,” Kanemoto adds. “Since then we’ve seen the shape of frames and swingarms change, so that when the bike is over on its side the rigidity is reduced, but when the bike is upright it’s very rigid.”

Kanemoto rates 1989 as his toughest season, even more gruelling than 1985, when Spencer won the 500 and 250 titles. He went testing between most races, which placed huge stresses on his tiny six-man (!) team: himself, Yamamoto, mechanics Jim Wood and Hitoshi Kohara, parts man Glynn Redmile and coordinator Alistair Taylor.

“When we had a weekend off we’d do the maintenance and assemble the bikes, but then we’d get to the next race and there’d be a load of new parts from HRC. The dedication of those guys was incredible, so the success was very much a team effort. You couldn’t run a Moto3 team with what we had then!”

Round eight at Rijeka was the other big breakthrough; not the race itself, where Lawson finished third, behind Rainey and winner Kevin Schwantz (Pepsi Suzuki RGV500), but another test session.

“I asked Eddie if we could test the day after the race, but he was so disgusted by the race result that he wanted to go home [to California]. Anyway, he agreed to test because Michelin had brought a new 16-inch front slick. He tried it and the profile helped the bike a whole lot. Eddie always put in the effort, no matter how bad things were. To see what he went through to win that championship; most people would’ve crumbled.”

A month later at Le Mans, Lawson achieved his first pole/victory result, while Rainey was beaten into third by Schwantz.

The next two races were on back-to-back weekends: Donington, then Anderstorp. Going into these two races Lawson had reduced Rainey’s lead to just eight points, but Kanemoto wouldn’t let up. HRC air-freighted a whole new bike to Europe, which Lawson tested at Donington a week before the British GP, while another NSR was driven to Anderstorp.

After testing at Donington the team flew to Sweden to test again, then flew back for the British GP, while the Anderstorp bike was returned in time for practice, so Lawson started the weekend with three different bikes in his garage.

Schwantz dominated Donington, like he usually did, while Lawson beat Rainey once again, moving ever closer to the title lead. Just three races left: Sweden, Czechoslovakia and Brazil.

Lawson had the momentum and fought a thrilling duel with Rainey at Anderstorp, which ended when Rainey crashed out, putting Lawson ahead on points for the first time. Two weeks later at Brno, he again bettered his rival and another three weeks later was crowned champion at Goiania in Brazil.

The chassis and engine work that Kanemoto, Lawson and HRC did during 1989 set Honda on the road to championship domination in the 1990s and began the process of transforming 500s from malevolent bone crunchers to arguably the greatest race bikes of all time.

In 1990, when Lawson returned to Yamaha after failing to agree terms with Honda, the NSR500’s even-spaced 90-degree firing configuration was replaced by a 180-degree configuration, which fired cylinders in pairs to improve traction. This was the first step towards the big-bang engine of 1992.

“During 1989 the engine character caused a lot of what people thought was a handling problem,” adds Kanemoto. “We got a big gain with the 180, because the power hit wasn’t so abrupt, so the rider could start to open the throttle when the bike was leaned over.

“A lot of that was down to Eddie, because he’d ridden the Yamaha, so he knew the engine could be more friendly. I remember saying to him at the start of 1990, ‘You left one year too early!’. HRC had its eyes opened – they realised that this handling thing isn’t just the chassis, it’s engine character too.”

Lawson only took one more GP victory after 1989, when he won the rain-affected 1992 Hungarian GP with Cagiva. Honda meanwhile refined the NSR into the most successful 500 of all time. The final piece in the jigsaw was the seminal big-bang engine configuration, unleashed in 1992, when Doohan ran away with the championship until he mangled a leg at Assen. He came back from that to win five consecutive titles, from 1994 to 1998. The NSR won seven of the last eight 500 titles.

Lawson’s take on the Honda

During 1989 Lawson never criticised the NSR500, even when it was obvious that the bike wasn’t right. He had criticised Yamaha’s YZR500 – largely due to ongoing carburation problems – but remained fiercely loyal to Kanemoto and his HRC engineers. This is what he told me about the bike a few years ago…

“The bike wasn’t bad. It wasn’t as nimble as the Yamaha, but it was stable and didn’t do anything really bad. And it was a rocket.

“Between Erv and I we made a lot of changes: chassis stiffness, suspension and so on. Honda kept telling us the chassis needs to bend like a tree. No it doesn’t! [He’s since been proved wrong on this.] So we went off in the complete opposite direction to Gardner, and the chassis kept getting better and better. So HRC went, ‘Wow, Eddie knows what he’s talking about!’.

“If we made a change to the bike I was never afraid to say it’s worse or I don’t know if it’s better or worse. I think a lot of riders ask for changes, then they’re like, ‘Oh man, it’s worse; I can’t tell them it’s worse!’. It’s not that I knew that much, it’s just I wasn’t afraid to tell them exactly what was going on.

“With the Yamaha we had kept making the crank heavier and the engine kept getting better, so at one point I thought this thing needs a heavier crank. By then HRC would do anything I wanted, so Erv asked HRC to make a heavier crank. I went out for practice at Hockenheim and the engine was a turd, it wouldn’t get out of its own way! So I said sorry, ‘I screwed up!’, and the HRC guys laughed. But they were happy with me because I told them it was bad.”