Cycle News - Archive Issues - 1970's

Cycle News 1979 08 22

Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles

Issue link:

Contents of this Issue


Page 47 of 47

11 is possible to do things to the geometry, however, that may cramp the rider's position, Arnold indicated. The rider has his own feel for the motorcycle, Arnold said, and so there are compromises to be made in determining how much travel is needed in the forks and what type of damping to use for a particular track to suit the rider's style. To keep suspension in tune, Honda has relied more on outside vending because they have had some problems in the past with their own suspension company, according to Arnold. "So I have experts I am allowed to call on out in the field who can tell me what the optimum shock ratio is for a new shock, and I can set up my motorcycle per his recommendations," Arnold said. "1 can make his recommended shock absorber work very well on my motorcycle according to shock geometry and swingarm length. All I would have to do during the course of the year is change spring rates a little bit, and keep the shocks rebuilt. That's usually how I handle setting up the suspension. "We don't have access to a shock dyno here at Honda. The company gave me specifications for the front forks only. So we've experimented with going to much less compression and a higher spring rate to get rid of that square·edge hydraulic situation that develops during high piston speeds. We could cut on the piston to give it more flow passage at something like five meters per second, yet they can take the same parts in Japan and put them on their good shock dynos to get a good indication of what's going to happen." Arnold also .says more and more stock is being placed on the type of tire being used now because on any given din bike, there are only so many factors that induce traction. Only so much horsepower can be put through a tire patch that is sitting a few square centimeters on the ground. On tracks with a lot of composition, the secret, says Arnold, is going with a deeper tread that's got a harder rubber compound which digs down into the surface a little bit. But on a hard Southern California track, he would have to use rubber compound that was much softer and much more pliable to the ground. But such a tire will probably wear out twice as fast so that it would have to be changed between motos. Arnold related the story of Jimmy Weinert's mechanic once putting a paddle tire on his rider's bike when they came upon a sandy track. The whole outcome of the race that day was dependent upon how much traction you could get in the deep sand. Since there was no rule infringement, Weinert's bike clearly had tile mechanical advantage that day. In between races, Honda is building project bikes to test out various chassis. swingarms and shock as a test program for the Nationals, says Arnold. There are many options, he said, and that's one way of trying them all, even if testing at the races is not conducive to winning championships. But what pans out in the field may very well go into production machinery. "The factory is always thinking a year, or two or three down the line in production," conceded Arnold. "Besides being used for racing, our bikes are development tools for Honda's production bikes. You can't really take the same motorcycle you had last year and prepare it for the next season because it will JUSt be obsolete," Arnold justifies. "The sport progresses so fast, the stuff you had the previous season usually isn't very much good to you the following year." According to Arnold, the racing effon by Honda, until recently, has been mostly a sales·oriented outlet. "The company decided to race motocross," he begins to emphasize with analogy, "so t/ley called the guys in Research and Development and said 'build us a motocrosser.' They get a group of engineers who are working on lawnmowers, air compressors. and whatever else, and for maybe three or four months they concentrate on the motocross effort, designing a motorcycle and shipping it to us, and then they go on to something else. Well, if problems develop with the motorcycle, or something out of the ordinary happens, you have basically nothing to fall back on in the case of an emergency. They're probably building snowmobile by that time. "At present, we have a fulltime race project in Japan. which is something Yamaha has always had. Honda has finally decided in recent years that they're going to get serious about 'the motocross effort. So th y're building the machines all year aound and keeping the same group of engineers so they don't forget what lhey've learned last year." The engines that Arnold builds for Marty Smith are based on production machinery, bUI they definitely do have special parts in them, Arnold acknowledges. and they're essentially stronger. He indicated one engine could possibly go to the Before Marty Smith can do well on the track. Arnold has to have done his job well. off the track. Nationals, but he 'Usually relies on two. With replacement parts, they'll go the season, but Arnold takes the engines down every week. He'll get perhaps eight or 10 hours on a set of seals before changing chern, but after three weekends he changes the main bearings and seals, regardless. "It's not very practical to have both bikes running, in my opinion," says Arnold. "If both are running. the rider is going to take them out for a test ride and reach the conclusion that one has a better engine, or maybe one has the better forks, so it actually creates more work. You also have to log all this stuff down on paper, like how much time you have on your engine and crankshaft, gearbox, and forks. All you~ special parts and best pans are on the race machine, and it's difficult to tally' everything if you divide it all between two machines. So if I get two bikes, I usually take one apart so I'll have a spare frame if Smith cracks one, because you cannot change motorcycles in the course of competition that day." Arnold can just about ask for any power curve he wants from Japan. He'll play a little bit with flywheels and with port timing, and if he can't get the power he desires, he'll ask for improvements. Arnold revealed that he works closely with Daryl Bassani in building experimental pipes for Smith's machines. "With an Open bike, I would say you can get away with a lot of seat·of·the·pants testing just to get that rideability out of it. Bassani will make me three or four pipes, then we'll go out and run them to find the right combination. We depend more on feel when tuning a motocrosser, rather than dynotuning, which is pretty much the case with roadracers. " To develop that "feel," Arnold rides the test bikes. Being able to do so, he says, helps his communication with the rider. "When you go out and ride the machine, you can feel exactly what it is the rider is talking about. I can't ride at professional speeds," Arnold will admit, "but I can go Intermediate and Expert speeds on a local level. " Arnold claims the riders don't know enough about the mechanics of a motorcycle to come back and tell him, for example, that the machine is unequivocally locking up under square·edge bumps. But they know enough to mention that the machine feels rigid. Arnold says he can't actually rely on the rider that much to tell him exactly what the machine is doing, because he claims the rider will tell him plain terms that it's JUSt not working. "Smith is not really all that concerned about the motorcycle, anyway," Arnold reveals. "He likes to work on his practice bikes a little bit, but let's just say I would nen'r let him touch a race bike. He has a tough lime; I think a lot of them (racers) do. Marty more or less leaves the mechanical considerations up to my judgment. He worries about resting and getting ready for the next race, He doesn't stand around and watch me," What Smith does do, Arnold's wife disclosed, is play backgammon with her between motos in their motorhome. If he doesn't beat her, he becomes a trifle 'u pset. according to her report, and then another game has to be played quickly before race time, "Sometimes I let him win," she says. Part of the overall psychological conditioning program, you might say. For Marty Smith's main attribute as a rider that would set him apart from all others, in Arnold's estimation, has to be physical conditioning; and with physical conditioning comes mental conditioning. "You develop an awful lot of confidence in yourself when your body is in good condition. Marty is a smart rider, and he doesn't take a lot of chances. But he's avery, very fast and consistent rider. He won't take unnecessary chances where he doesn't need to and pay for them later. If it means taking a second in this moto, then he'll make it up in the next." Fitness has never been a problem wilh the 22·year· old former champion. It has been for a lot of riders, but Smith seems always in excellent shape. For one thing. he works out quite often in Jim Brown's private club in Carlsbad. He also lives on a hill above Point Lorna in San Diego, and he runs up and down the hills around Sea World. He'll ride three times a week for at least a couple hours at a time. So how is it, Arnold was asked, Smith got edged out so easily while at the top of his form? "Burgett has always been a real talented rider; ,he just wasn't very consistent unlil last year. I would say during 1978, his body shape had been better than it ever was. I think the Yamaha racing manager may have called him and said it was either that year or nothing, so he got into real good shape, He also got a trainer to go around with him to make sure that he stayed in shape, Along with that physical conditioning, I think it really helped his mental attitude out a lot. He was much more consistent in the racing; he just wouldn't show a good moto and then a bad moto." In spite of the attributes of Smith as a rider and the caliber of Arnold as a tuner, it has been Bob Hannah ruling the Supercross series. Why doesn't Smith do as well? "I know Marty doesn't like the Supercross races as much as the outdoor races," Arnold commented in reply to the query, "He's just flat scared of stadium racing; a lot of riders are. In stadium racing, there is more of the go· attitude, with no real pace to the race, and a lot of chances are being taken. It's all because the tracks are set up for the spectator.s, and you can't really discredit it, because that's what it has come to. You c~n draw a much bigger crowd. There's a whole new generation of riders bred to this sort of racing. Bob Hannah won the Supercross series agaIn, and it's very important to Yamaha," Arnold added. thinking, no doubt, about Yamaha's sales camp,ugn. Pity is, before Arnold went to work for American Honda, he applied for a job with Yamaha, bUI was told he had n experience working on rac b:kc. Besides, his hair was too long. Doesn't seem to have affected Hannah's performance, Or Arnold's, for that matter, • 15

Articles in this issue

Archives of this issue

view archives of Cycle News - Archive Issues - 1970's - Cycle News 1979 08 22