The Harley Road Racers




The early RR250
Image: Classic-motorbikes.net



The words, 'Harley Davidson' and 'road racing' just don't seem to fit together. There's a good reason for this. From 1969 until 1981 Harley was owned buy the misguided bowling alley manufacturer AMF. In 1981 Harley was bought by a group of 13 investors led by Vaughn Beals and Willie G. Davidson for $80 million. One of the first things they did was design a new engine. Realizing that they weren't all that well equipped to do it on their own, they turned to Porsche for help. This partnership resulted in the new 'Evo' engine. The new engine looked and performed similar to (that was the intention) the old ones, but there was one big difference, it was reliable!



A water cooled RR350


It was a smart move, and another smart one was the decision not to take part in the technology battle of the other manufacturers. Harley believed that there was a substantial market for a traditional 'raw' motorcycle and they were right. They also realized that there was no real competition in this sector and went on to become the sales success they are today. Only now are they experiencing the only serious competition they have had since their early history, from the same manufacturer, Indian.



Walter Villa won 3 World Titles on the 250 and one on the RR350


This is all a round about way of saying, they don't need to go road racing, but this hasn't always been the case. In 1960 Harley decided that they needed some smaller capacity bikes to compliment their range of big v-twins and they purchased a 50 percent share in Italian manufacturer Aermacchi. H-D acquired the remaining 50 percent in 1974. It was felt that road racing would be a good way to promote the smaller range so they formed a four man race department to build a bike.



A Bimota Harley Davidson

The two strokes

They built two! Working out of Aermacchi's lakeside factory at Varese, Italy, the understaffed race team built the RR250 and the RR350. The 250 was basically two 125cc motocross engines, joined via a common casing and the internals were mainly Yamaha TR and later TZ parts. The RR350 was simply an over bored and stroked 250. The bike was lighter than the Yamaha and by the end of 72 Renzo Pasolini had finished 2nd in the 250-world championship and 3rd in the 350-title. The following year Pasolini was killed at the Italian GP in a tragic accident that also took the life of up and coming superstar Jarno Saarinen.

Water-cooling was added in 1973 along with cast wheels and disc brakes. The front Campagnola wheel had the disc inside a conical hub and looked like a small drum brake, but it seemed to work ok. A Yamaha styled monoshock was also added but in 1976 they went to a Bimota frame with twin Marzocchi rear shocks. In 1974, Italian Walter Villa took the RR250 to the first of three consecutive World Championships and in 1976, added the 350 for a double.

Buy 1975 Harley had wanted a presence in the premier class so the race department was called on to try and come up with something, they did, and the bike was called the RR500. It was a 488cc water-cooled reed-valve 2-stroke parallel twin with four carburetors, yes, four. It had a 12:1 compression ratio, weighed 124 kg and put out 89hp at the back wheel. It used a Bimota chassis and was potentially a bit of a weapon. It competed in the 500cc World Championship in 1975 but the four-cylinder power of the Suzuki's, Yamaha's and MV Augusta was just too much, and it was scrapped in less than a year.

In 1977 an attempt was made to sell replica RR250 and 350 production racers to the public but they were much more expensive than the Yamaha offerings, and by this time, not as good. Harley slowly faded from the GP scene, never to be seen again.



The XRTT 750
Image: Silodrome

Formula 750

Meanwhile, away from the world of Grand Prix, there had been another form of competition developing, called Formula 750. The bikes were supposed to be derivatives of a road bike, a bit like Superbikes today, but it evolved into what seemed to be, 500 GP racers with an extra 250cc. Yamaha brought out their TZ 700 4 and somehow managed to convince the controlling body that it was based on their RD 350 road bike, it's just that there were two of them! Some big money venues like Daytona and Imola were behind the formula and for a while it looked like it could overtake the 500s as the premier category.

One very popular series for Formula 750 bikes was the Trans Atlantic Match Races or Trans Atlantic Trophy, held each year at Easter on three different UK circuits. A team of the best UK riders would be assembled to take on the best from the US and the series drew worldwide attention. In 1972, the brilliant Harley Davidson factory rider, Cal Rayborn, convinced the reluctant management to let him take the antiquated XR750 to contest the series. The pushrod, cast iron head engine of the XR750 came from the Harley dirt trackers and had been the same for years. They had no real serious competition on the flat tracks, but international road racing was a different deal altogether. No one gave it a chance against the three cylinder two strokes from Kawasaki and Suzuki and the BSA and Triumph four stroke Triples. The UK also had star riders like Phil Read, Ray Pickrell, Peter Williams and Tony Jefferies who knew the UK short circuits like the back of their hand.

Rayborn hadn't seen any of the tracks but went out and won three of the six races and was second in the other three, setting new lap records as he went. The Harley wasn't meant to be that fast and it really wasn't, Rayborn's brilliant riding made the difference. Rayborn had won two consecutive Daytona 200 races in 1968 and 1969, but that was over three years ago and the bike was considered outdated then, it hadn't changed much since. No one expected him to win.



Cal Rayborn on the XRTT750


Towards the end of 1973, it was apparent that the Harley-Davidson team could no longer provide him with a competitive motorcycle for road racing, so Cal accepted an offer to race for the Suzuki factory. In December he was invited to ride at the New Zealand Pukekohe Park Raceway. This was to be the scene of tragedy. Again Cal was riding an uncompetitive bike, as the only one available for him was the TR500 twin, not the three cylinder 750. The bike was hurriedly converted to run on methanol (allowable then) and seized, throwing him into a wall, killing him instantly.



A non factory, XR1200 by Shaw Speed and Custom

The Superbikes

There was no more factory involvement in road racing until 1986, when HD CEO Vaughn Beals attended a race at Laguna Seca. He was concerned by the lack of Harley owners present and set about doing something about it by introducing a plan for racing a Harley superbike. They didn't have anything suitable to use as a base bike, so they needed to build something from scratch. An air cooled v-twin was first proposed, but Erik Buell, then operating independently after working as an engineer for Harley from 1979 to 1983, suggested developing a modern liquid-cooled V-twin with double overhead cams, fuel injection and four valves per cylinder.



The VR1000 Superbike


This was the road they chose and they started with a clean sheet in 1988. Buell was hired to develop the chassis and also drew up some blueprints for the engine. HD designer Mark Miller was to develop the engine with engineering input from Cosworth, Roush Industries and Jerry Branch from Branch Flowmetrics. Miller designed a unit construction bottom end with dry sump lubrication based on Buell's specs. Steve Scheibe, an engineer and experienced road racer who had already done contract work for Harley, was later brought in from Roush. He became an influential force in the project.
Engines were built using sand cast components and the first gearbox design was based on a modified XL five-speed unit. A 60 degree vee layout was chosen at the expense of the primary balance of the engine. The lack of balance would later trouble them.



The V-Rod engine was a developement of the VR1000


The Cosworth engineers had suggested that one of the best ways to get power out of a four-valve engine was to feed it as much air as possible. There wasn't much room for a large airbox though, as Buell had designed a twin spar aluminium frame to house the narrow angle twin. Buell then came up with the idea of using the big twin spars as a fuel tank, utilizing a pump to get the fuel up to the injectors. An idea he was to later use on his own bikes.



The VR1000 had many variations in its quest to become competative


It seems that the initial bikes put out 116 hp at the back wheel and weighed around 200 kg. The bike had a multitude of variations over the course of the campaign in an effort to make it competitive with the Ducatis that were the benchmark of the class. A six-speed gearbox with a counterbalance was fitted and later versions had a frame designed by Mike Eatough, which was built by Harris. Riders raved about the handling but the bike suffered from lack of power and poor reliability.

Titanium, magnesium and carbon fibre was used to cut the weight to around 170 kg and reliability gradually improved. The VR was producing around 140-150 hp when it was first raced, but that was at least 10 horses behind the competition. Some sections of the management had not been keen on the project from the outset due to the costs, and the needs of the race department were not top priority.

Production began in 1994. The first 10 examples were built at Roush Industries. To be legal in AMA Superbike racing Harley needed to produce a series of 50 somewhat street-legal machines for homologation. This was going to be difficult as there were no real provisions for making the machine street legal beyond slapping on lights, turn signals, and a starter. A certain executive at the company put it bluntly to the team: "Go somewhere in the world and get us a homologation certificate." A lone VR1000 was given a certificate of homologation for sound and emissions in Germany. That proved to be good enough for the AMA.

The bike was campaigned from 1994 to 2001 in the hands of such riders as Miguel Duhamel, Doug Chandler, Chris Carr, Pascal Picotte and former World Superbike champion Scott Russell. The effort yielded one pole position, two second-place finishes and a handful of thirds, but victories remained elusive. A combination of unsatisfactory results, in house power struggles and the acceptance of the fact that they were spending a lot of money on a category that was not aligned with their road bikes, spelt the end of the superbike program. With the current real threat to HD's market dominance from Indian, there is possibly a glimmer of hope that we might see Harley back on the tarmac sometime in the future.



Written by Paul Harmon, 28-1-18
References: odd-bike.com
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