1972 Suzuki RH72
1972 250 World Champion
In relative terms, the 1972 RH and RN works Suzuki’s are arguably the most advanced motocross bikes ever built. They were the pinnacles of research & development from a project to build a world championship-winning bike that began back in 1965. In 1968 after attempting to hire Torsten Hallman away from Husqvarna and Joel Robert from CZ, Suzuki hired GP veteran Olle Petterson to aid in further developing the bike. By 1970 the RH250 was refined into a GP winner and it was then that Suzuki’s checkbook came out and they added Belgian world champion Joel Robert and fellow countryman Sylvain Geboers to the team for their first official attempt to win the world title.
In January of 1970 Joel and Sylvain flew to Japan to tryout the brand new RH70. The two GP stars had nothing but praise for the lightweight, precise handling, good power band and excellent peak power of the bike. One of the first things Joel commented on was how the bikes light weight reduced rider fatigue and how easy it was to control. Nothing like this had been built before, as the RH weighed only 187 lbs., which was 35 pounds lighter than the Husqvarnas and CZs that dominated the championship. The RH70 had an advantage never experienced before. Both Joel and Sylvain believed that the bike was so much better than anything else they had ridden, that they would easily win the world championship.
Just before the start of the 1970 grand prix season, Suzuki team manager Ishikawa was asked if the 250 Suzuki RH70 could take the title. “Without fail,” he answered. It was a bold prediction but Ishikawa’s confidence was not misplaced. Very few machines have so completely dominated a motocross season like the RH70 did in 1970. By the end of June that year, after taking 7 of the first eight races, Suzuki had the manufacturers cup clinched-this, with 4 more grand-prixs to go through September on the brutal European circuit. Further, by seasons end, Joel Robert and Sylvain Geboers, two of the three man Suzuki team, had locked up first and second positions in individual standings. Olle Petterson added sixth place to cap an outstanding year.
The success of the RH70 had everyone scrambling. Compared to the much smaller European manufacturers, Suzuki had unlimited funds therefore making it all but impossible to compete with. 1971 was a repeat of 1970 as Suzuki dominated and the 1971 RH was more even refined. Suzuki also expanded their efforts and entered the 500 class, hiring Roger DeCoster and winning immediately.
In 1972 motocross went bananas. Husqvarna figured that throwing money at the sport was the recipe for success. The Swedish company built titanium-framed works bikes with specially built compact motors to challenge Suzuki, just as BSA had done earlier. The 1972 works 250 Husky was said to weigh just 176 pounds-the research and development cost must have been staggering to the small firm. Imagine the horror the proud Swedish engineers must have felt when they saw the RH72 weigh in at 168lbs. at the first GP near Barcelona Spain!
To the rest of the world, the Suzuki’s became mysterious and awesome. The Japanese engineers were so secretive that rumors and legends spread quickly throughout the racing world. The bikes were covered almost anytime they weren’t on the track or being serviced. What were they trying to hide? The bikes were said to be all titanium, magnesium and other inaccessible space-age materials. Suzuki even ran ads stating that the bikes cost $15,000.00 each. As expensive as that was, in reality it was many times more and to this day no one knows exactly how much Suzuki spent on the bikes. Curiosity about the RH turned into outright lust and then to jealousy.
The commotion over the $15,000.00 Suzuki’s reached a climax by the end of 1972. Both Joel Robert and Roger DeCoster had been unbeatable in their respective classes and the jealousy that ensued had political repercussions. A group of small European companies led by Maico pulled all the political strings they knew how. They claimed the works Suzuki’s were an unfair advantage and that there was no way they could compete with all the aerospace materials Suzuki was using. They claimed that the bikes were unsafe and used the example of a horrific crash Torleif Hansen had in Switzerland when the titanium frame on his works Husqvarna broke in half after landing from a jump.
Just before the 1973 season began, the FIM acted and implemented a minimum weight rule. Any motorcycle competing in a 250GP could weigh no less than 196lbs. and titanium was banned on frames and axles. This was devastating to the Suzuki team. The RH73 was already built and was now 30 lbs. under the limit. At the last minute the bikes were fattened up artificially and did not respond well to the changes. The magic of the RH72 had disappeared.
The bike featured here is the RH72 that the great Joel Robert used to decimate the competition with in 1972. Two bikes were issued to him at the beginning of the season but he only elected to use this one. When asked why he never rode the second machine. Joel’s response was, “This one was good enough, I never rode the second machine, it was brand new in the truck as a spare.”
One of the most amazing things about the RH72 is how simple it is. Every single part on the bike was designed to be a part for an RH72 and to be as light and functional as possible. For example, the rear wheel spacer that has absolutely no load or pressure on it is made from nylon. The lower rear shock fasteners are titanium pins with cir-clips holding them in place.
Suzuki did not just make every part as light as possible and making the bike unsafe as claimed. The front forks for example, are much heavier than even some production forks of the day. Suzuki used very thick and strong metal for the fork tubes to reduce flex but made up for some of the added weight by machining very thin fork sliders. The frame is the same way. It is made from very high quality chrome moly tubing and therefore thinner walled tubing could be used to save weight. The frame weighs in at just over 15 lbs.
The swing arm is another part that got the lightweight treatment. Made from aircraft quality aluminum the shock mounts were machined from billet and heli-arced in place. The unit weighs just over 4 lbs and to top it off, it was held into the frame with an aluminum swing arm pivot bolt capped with an aluminum nut.
Inside the engine, everything is so simple it looks like parts were left out yet every part has a function and no unnecessary brackets or hardware is used. The result of this engineering is a 250cc grand prix engine weighing in at 35lbs.
It is obvious by the way the bike was constructed that it wasn’t even remotely considered for production. This bike was made to last two forty-minute plus two lap motos and that is exactly what it did. Parts were changed often, as the bike would be returned to the European Suzuki headquarters at Nimag in Holland where it would be completely disassembled, inspected and rebuilt for the next GP.
With the implement of the FIM minimum weight rule for 1973 an era in motocross technology had ended. The secrets of the RH72 remained secrets until it was discovered and began a one-year restoration. Thirty some years later it is still hard to conceive that a GP motocross bike that weighs 168 lbs. is even possible let alone was actually built. That coupled with what some say is one of the greatest riders of all time made for one of the most dominant seasons ever.
1972 Suzuki RH72 Photos
Joel Robert’s comments:
The Suzuki works bikes from 1970 were mostly the result of Olle Petterson’s work with the factory. From 1970 thru 1972 they were refined mostly from the Japanese engineers. We did not do as much development work as some people think. Most of this was already done by the time we got to Japan to test the bikes. The bikes used very simple engineering and were not as exotic as everybody thought. Yes they did use special materials but it was the design that was so unique. The shock bolts were titanium but instead of using a nut they used a cir-clip to save weight, things like that.
Most of the time the bike was perfect right from the start; We would be at the test track and there would be all these engineers with different bikes, frames, cylinders, and everything you could imagine. I would adjust the bars and go out for the test laps and everything was good. They were very surprised when I would come back and say “It’s good; give it to me like that and I will win.” On time I was in Japan testing and I pulled off at the back of the track to have a cigarette. When I came back the engineers said “Hey what happened to you.” I told them I had a big crash. Later that day we were at the factory and the engineers were watching film of the test session. I didn’t know they had cameras all over the track. They got to the spot where I stopped and they said “Is this where you had your big crash?” It was pretty embarrassing but everybody laughed.
The Suzuki RH72 was also very reliable. I broke the frame in half one time in Czechoslovakia on the last lap while I had a one-minute lead but still got second. The frame broke right below the steering head so the clutch cable was the only thing holding it together. Every time I went over the bumps the clutch was pulling in and out.
The main advantage to the RH72 was the weight advantage. It was so light and took very little effort to ride. The suspension was very good too. You could really feel the advantage at the end of a 40-minute moto, rider fatigue was greatly reduced because of the weight. Another advantage the weight gave was you could put the bike anywhere on the track you wanted, as it was very responsive to rider input.
The engine made a lot of power, but it made real good power and had a very good power-band for motocross.
Overall the bike was fantastic. The lightweight, suspension and power were a well-balanced package.
With four grand prix’s to go I clinched the world championship in the Soviet Union. It was the first time I handled my own travel arrangements and it ended up being a weekend where I had border crossing problems, I ended up in jail for a brief time due to a conflict with a Russian guard and finally got to the track on Sunday just about when practice almost over. I had not slept for nearly two days and my few practice lap times were not so good. I remember the Japanese mechanics looking at their stopwatches and shaking their heads when I got back in the pits.
Just before the race started, the heavens opened up and it started to rain. It rained so hard that in minutes the track turned into a quagmire. I was known as a good mud rider and I knew then that I had an advantage. This gave me some added adrenaline and motivation and I ended up winning both motos and was crowned World Champion for the sixth time. This was one of the most memorable moments in my career.
I really enjoyed my time at Suzuki and working with so many people. The people at Suzuki were like family, we all got along and I think this was in part what led to the huge success we had there.
Joel holeshots with the incredible RH72. That's Hakan Andersson in second on the works Yamaha.
The great Joel Robert on the RH72 for the first time during Saturday's practice before the Spanish Gran-prix 1972. This is the very bike in this collection.