Four-Star Showdown
FOUR-STAR SHOWDOWN
Comparing the Honda CR250R, Kawasaki KX250, Suzuki RM250C2 and Yamaha YZ250E
CYCLE WORLD TEST
Motocross racing is the game and Replica is 1978’s name. For the 10 years or so that motocross has been a major sport in the U.S. and a major market tbr the big factories, most of the time there has been one make ruling the roost and everybody else scratching along behind. The popular thing has been for the champion to whip out copies, more or less, of the winning machines and let private and amateur and beginning racers fight it out with what the pros were using last season.
Often as not. these copies weren’t too close to the work machines. For a time we even had two brands not making competitive motocross bikes, while the other two swept the races and the sales contests.
And now. wow. For 1978 Honda. Kawasaki. Suzuki and Yamaha each have competitive MX weapons. Two. from Honda and Kawasaki, are new. Suzuki and Yamaha have improved versions, with some of the improvements edging toward creating a new model. All four are in the 250 class.
A logical choice. The best 125cc racers are lightweight berserkos, able and willing to keep the little screamers on their raucous pipes all race long. Open class racers have more power than any rider short of Expert status can use (although that doesn't keep beginners from buying them).
The 250 class has room for all.
So. We have the closest competition in years. Not to slight the smaller companies, but the Big Four brands tend to control the market through size as well as product. Thev have the money to invest in a racing program, the sales volume to allow production at lower prices and dealers enough to put a racing bike in the hands of everybody with the down payment.
It will come as no surprise that CW views this situation w ith pleasure. To have a choice of fine machines is great. To have an excuse to compare these fine machines is better still. A comparison test is a useful way for us to analyze the strengths and weaknesses of the for-sale versions of each model, to subtract the skill of each team’s riders and w renches from the equation.
Next, we can add to the equation. Before looking at the bikes under review it's worth noting how similar they are to each other.
Big factories don't take big chances. At this time the tw'o-stroke has an edge and a Single works better than a Twin. Telescopic forks with leading axles are virtually required, as is a swing arm in back.
There are some good privateers working with four-strokes and even wanning. There are doubtless demon tweakers building motocross Twins, leading link front sus-> pensions and parallelogram rear suspensions as well. Instantly any of these demonstrate a clear advantage over what's in production now. that idea will become production. Until that happens, the main men will build what's working now and that means they'll be building pretty much what the other leaders are building.
Thus Honda. Kawasaki. Suzuki and Yamaha have 250 motocrossers with twostroke Singles, reed valves, long-travel suspensions. etc. As is shown bv the charts on these pages, the four rivals are close to each other in terms of weight and wheelbase. ground clearance, seat height and myriad other dimensions.
There are clear trends, year to year. As a sample, three of the four bikes in this group have . . .
. . . full-floating rear brake . . . backset handlebar mounts . . . aluminum swing arm . . . single front downtube . . .and air-pressure front forks.
(The exceptions, in order, are Yamaha. Honda, Honda, Yamaha and Honda.)
Dumb people don't work in the racing department. The general outlines of the rival racers are close because the outlines work.
And they are different because each team has its own thoughts on the matter. Each engine crew has its opinion of the proper balance between low-end torque and top-end power. Each department has its limits w hen it comes to spending money to reduce weight. Each staff' of test riders and racers uses its own judgment in picking spring and damping rates, front/rear weight balance and the like.
So each bike is different while each bike is like the others.
This is important as well as interesting. The winner's edge is bound to be narrow and it’s bound to be hard to find.
All the better. The standard comparison test comes down to numbers and opinions. Sometimes this is a matter of points, that is. so many for speed, so many for price, so many for seat comfort.
Inappropriate here. These are racing bikes. While price and ease of maintenance are worth thinking about, the reason anybody buys a racing bike is to be as quick as possible. Winning, or failing that having a machine that w ill let you do the best you can with the talent you have.
So. The winner will be that bike that turns the best lap times.
Unlike the ball-and-stick games, winning will not be the only thing. No two tracks are alike, nor are two racers alike.
Along with which bike goes around the track fastest, we’ll be determining how and why and w here.
The collective we covers a wide span. The riding for the track times and special stages was done by four men. Because this is a test of machines rather than men. the ruling times will be those turned by the professional racer. Next in skill came the Intermediate, then the Junior. Both riders have experience in motocross and off-road competition, both are good riders but are not (yet?) good enough to race for money. The fourth man has done no racing and doesn't plan to do any. He’s a cowtrailer. enlisted for this venture as a control: howtricky are these Replicas to ride? Can they be controlled and enjoyed at less than competitive speeds?
About Replicas: Each of the models here are close to what the factories race. None of them are true works bikes. Instead they are as close to pure team machines as it's practical for their makers to produce.
Two areas of difference. One is engine tuning. The factory teams have more power. When you have a van full of fresh engines, you can afford to build two-moto grenades. You can't afford to sell them to customers. The team mechanics and tuners can add to this difference, and they do. If they didn’t, they'd be looking for new jobs.
Second comes weight. Less weight is like more power, in that it costs money. Raee teams work to a limit, usually expressed in the number of dollars they can spend to lose each pound. A normal racing ratio is $100/1 lb. If the legal minimum is 206 lb. and the works bike weighs 21 1 lb.. $500 is worth its weight in titanium or even unobtanium. But a 21 1-lb. production bike for $1500 retail is a better deal than a 205-lb. bike at $2000.
Those areas and running changes aside, what we see here is near as dammit to what we'll see come out of the factory vans this season.
This comparison test took some thrashing. Each entrant is entitled a complete test, which was done w ith the RM250C in CW for October. 1977. and with the CR250R in CW for February. '78. The KX250A4 and YZ250E are tested in elsewhere in this issue. And so quickly does the art of motocross change that we've just received the RM250C2. which gets an update of its own.
THE CONTESTANTS
For the record and to refresh our collective memories, each model now comes up for a brief review.
HONDA CR250R
The CR250 is the biggest surprise of the> sale. Ther
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KAWASAKI KX250A4
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has the largest `n er~of~fnall te en exIr~ tho'ught. as drilled contro counter-sunk heads, ne sitim i e o~F~r brands have a i~ m The~ auufu~ the best th~' bik `Ii v~b~iiIt with extf 1~~b:jIt1
SUZUKI RM250C2
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YAMAHA-YZ250E
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CONTESTS
At itS s~mp1t m tOCr~)sS~l, - fl$ist~ èf c ratit~ç~. bra~ , t ind ssing hu*~ps"?~için~ r' -k~p giant op~ñ~utbj~ the time, the bikes are doing two or more of these tasks simultaneously, that is, they are crossing stutter bumps under power, whoops under braking, turning in mud holes, etc.
In order to isolate these modes so they can be compared separately, the four test bikes were timed and measured for acceleration, top speed and sound level.
The drag races were held on damp ground that contained some gravel. The area had a consistent surface texture and each start was made from an undisturbed spot. Three runs were made at each distance with each bike. They were allowed to cool after each run.
Top speed runs were done on a hard packed dirt road in the desert. A radar gun determined top speed after Vs mile with the rider in a racing crouch. All speed testing was performed with stock gearing.
Noise tests were conducted using a sound meter. A full throttle, second-gear pass at 50 ft. was repeated three times and the highest reading logged.
All the bikes were loud. Strangely enough none had repackable silencers. We think all bikes should have repackable silencers and that they should be repacked often. Noise is one of motorcycling’s w orst enemies, even at the race track.
The results (see box) are not especially conclusive. If the results prove anything, it’s that gearing is as important as power and using the right technique is as good as the correct gears. The Yamaha had the most top speed, and was slowest in first gear to the first marker, while turning the best elapsed time to the second marker, starting in second gear.
The actual track testing told more, if only because that’s where the various virtues and shortcomings of each model matter.
No two tracks are the same, so it follows that one track wouldn’t be a fair test. The track sessions followed heavy rains and our choices narrowed to two: a smooth and sandy track being groomed while we were riding on it. and a hilly, rough, swampy, mean and nasty track that doesn't get groomed for weeks at a time. Terrible place.
The smooth track came first. Before times were taken, the four riders took each bike around in turn. When they knew the mounts and the course, they recorded their impressions:
HONDA
Pro: “Oh, it's plush. Soft and it goes beautifully over the bumps. Seems to oversteer, you need to crank in more steering than you think it needs, but that may be getting used to the bike.”
Intermediate: “Seems pipey to me. Front wheel seems to skate. Shifting is stift', although that may be because the bike is new.”
Junior: “The engine works fine. Tractable for me. The bike feels light and corners well.”
Beginner: “Nice. Everything works the way it should except the shifter is so close to the cases that I can’t always hit it first try. There is a pow;erband but the engine pulls all the time and doesn’t quit on you. This one seems the lightest of the four.”
KAWASAKI
Pro: “I rode it like a Husky. The power comes on hard and the front end is light. Back brake locks. Front is fine and it may be getting your foot used to the rear. The engine doesn’t feel especially powerful. Shocks are still stift'and the back end kicks. (Note: This disappeared after a few hours of riding.) Turning is excellent, goes just where you point it, like a 125.”
Intermediate: “This one’s neat. Forks are smooth and it turns precisely. The brakes work well although the back chatters some. The engine w'orks all the time.”
Junior: “It didn't make much of an impression. Must be lighter than the others and it is willing to turn when you want.”
Beginner: “The KX is the easiest to steer, I guess because of the weight and the height. I had to work keeping the power in control and the back brake is touchy. I locked it once so completely that I killed the motor. Could have been me. This one feels the stiftest of the four.”
SUZUKI
Pro: “1 don’t know w hat to say. I race one of these so I can't give a first impression. The C2 is better than my C 1. especially the suspension.”
Intermediate: “Forks are good and the shocks are just right. I bottom when I land after the highest jump, which is what’s supposed to happen. It isn’t as pipey as the Honda but in the whoops the Suzuki dances around. The Honda has better brakes.”
Junior: “I had trouble with the engine. It comes on the pipe hard and there isn’t the brake control the Yamaha has.”
Beginner: “Best grunt so far. The carb seems rich on the bottom but it will pull. Suspension seems stift' to me, but I think that's because I rode the lighter two bikes first.”
YAMAHA
Pro: “The monoshock is different. It has a higher center of gravity and you can tell. The bike wants to lean outward in the turns. It feels heavy, compared to the others. The suspension works in the straights and they have cured the kick in the back the first monoshocks had.”
Intermediate: “The front end doesn’t push the way the Honda’s does. The pipe burns my leg on right-hand turns. The front is> heavy and this bike is harder to wheelie.”
Junior: “After the Suzuki, the Yamaha feels heavy. It steers slower. Good brakes. The engine isn’t as peaky and I think the Yamaha is the easiest to ride.”
Beginner: “I rode the Yamaha first and it seemed to work fine. Not as much work keeping it in line, more stable in the sand. Maybe the slow steering is easier for me to deal with. This thing is still 40 lb. lighter than my own bike. I'm having a terrible time with the engine. Can’t ride it slowly, not at all.”
The lap times were more conclusive. With all machines checked out and working well, the four riders swapped bikes, riding for times on each.
HONDA
FRONT FORKS
Showa leading-axle fork
Showa’s latest forks excel in all areas. The cartridge-type damping unit provides rates which take full advantage of the long travel, yet the forks do not bottom or top. These non-air forks are adjustable by changing oil viscosity and/or spring rates, but most, if not all, owners will like them as is.
REAR SHOCKS
Showa gas shock, non-rebuildable
These pressurized gas/oil emulsion shocks are unusual for several reasons, among which are length (17.5 in.) and damping. Dyno curves show the valving to be mainly blow-off type, similar to older Girling units, and well suited to the 1.9:1 swing arm ratio. For this test, the softest of Honda’s spring options was installed, but the middle spring rate seemed to work best in pur original test.
KAWASAKI
FRONT FORKS
Kayaba leading-axle fork
At 9 in., travel on these KYB forks is adequate, but not exceptional. With the stock oil, damping was insufficient, however, and allowed the forks to bottom prematurely. An improvement in action was realized by using 10 wt. oil in lieu of the original.
REAR SHOCKS
Kayaba remote-reservoir shock
The KX's rear end feels much too soft, a condition which is reflected in the very low~ spring and damping rates. Even with its mild 1.6:1 wheel-shock travel ratio, the 55-lb. primary spring rate was insufficient. A 65-70 lb. rate would be better. Rebound damping, at 56 lb., also is insufficient, causing rear-wheel kickback and instability. A set of ac cessory shocks is in order here.
SUZUKI
FRONT FORKS
Kayaba leading-axle fork
Forks on the 250C2 are the same as those on the RM400, and work extremely well. Long travel and engagement combine with good spring and damping rates to provide a soft, controlled ride, with no adverse handling traits.
REAR SHOCKS
Kayaba remote-reservoir shock
These adjustable reservoir shocks from KYB should satisfy the needs of virtually all riders. Damping rates are quite good, and offer maximum control over most surfaces. Spring rate, a bit soft for the RM400, is spot-on for the 250C2.
YAMAHA
FRONT FORKS
Kayaba leading-axle fork
The YZE is equipped with the long KYB legs, offering much travel and engagement. Damping and spring rates are excellent, as is the very low static seal friction component. The result is a high level of control with no sacrifice in comfort.
REAR SHOCK
Kayaba DeCarbon monoshock
The DeCarbon monoshock on the Eseries YZ has been changed only slightly, but with good results. The rearwheel kickback of older units is gone, and control has been improved. Adjustable damping (in 32 increments) and preload of the single-rate spring allow a high degree of fine tuning.
First thing we did, though, was throw out the beginner’s times. They were so slow and inconsistent that they proved nothing.
Except perhaps that a 1978 motocross machine is a recreational device like, say, a hockey stick, a utensil for serious play, while a PE or KL or XL or IT is a recreational device like a tennis racket; you don’t have to play well to enjoy using one.
Best times on the smooth track were:
Well. The quickest rider on the slowest> bike could beat the >lowc-t rider of¥ the quickest bike, 'fhe.se ¡our mals are^ Jose in speed and speed potential as they are on the specification charts. This came as, a •surprise, mostly because they do feel different from each other. Turns out the four faetones have slightly different wavs of arriving at competitive results. More ort that shortly.
The smooth track was used for another drag meet. There's a fast, sweeping turn leading across stutter bumps to an uphill with a jump. Each bike was clocked from the turn's exit to the iip of the jump, the purpose being to measure drive and traction on rough ground. Lv, .. ' J J
The,Honda covered the distance in 5.5 sec. TlVe other three tied, at 5.6 sec.
The second track was dreadful. If YOU rounded up 500 demon Wlcers and ‘told them to teaf.Ywit into-the hills after a rain so they could rip the place up. if that's w hat's meant by natural terrhm. well, this’was natural terra in', The ‘beginner went out and Tode, just to prove he could gef-around the course. He did. Barely. And the times of tfie Junior were discarded. He was so far Qtf the pace, halt' a minute behind on a trayk that could be covered in less than two inmates, that the times meant nothing. The two remaining riders of record JKI:
Turns things around some. (Tur Pro said * he didn't exactly doubt the times, but that the clocks didn't show the ctreumstaheey. The track was changing minute to minute. If he'd had to guess, he'd have; said he'd done best on the Kawasaki. As we've seen from the drag races, the four.contestants have fairly equal power. In the mud with low c.g. and steering prevision counting for maximum, the Kawasaki felt best, he said, because it steered best.
The. intermediate was consistent with> that, because he did his fastest time on the Honda and Kawasaki, close as we could measure, and slowed down on the other two. Took practice, by the way. He also races an RM but after getting used to the bikes and the rough track, he did better on the Honda.
SPECIFICATIONS
HONDA
$1498
SUZUKI
$1579
KAWASAKI
YAMAHA
$1568
All four bikes turned out to be strong as anvils. At the conclusion of three full days at wide open throttle, jumping six feet in the air, churning through mud and the like, the damage was:
Honda. Chain tensioner roller wore out. front brake cable popped out of holder, front cable guides bent.
Kawasaki. Brake anchor arm bent, presumably against a rock.
Suzuki. Rear brake cable guide bent. shift lever loosened and fell off.
Yamaha. Tank decals fell off, all three chain rollers wore out, spark plug fouled (rider error?).
We also compiled opinions in re likes and dislikes, and summed up the models as they had impressed us after the riding and testing.
The Honda’s strong points are its engine and its suspension, with some reservations. The engine is tuned for top-end power.
which it has, and the CR250 is fitted with a relatively heavy flywheel. This doesn’t give torque, but it does give momentum; the bike will slog through the mud and isn't as likely to fall off the pipe as it would otherwise be. A good idea.
The suspension limits have to do with its advantages. All that soft travel makes the CR tops on the jumps and whoops. The bike is agile and it turns well, unless the ground is soft. The plush suspension then becomes a vagueness at the bars. The tires are biting but the rider can’t tell. Further, the long travel gives maximum pitch and thus the steering geometry varies with the machine’s attitude. Figure you're up 6 in. in back and down 6 in. in front. You’ve got a nearly vertical front fork and you've got a problem.
As minor gripes, the exhaust pipe scorched two of the riders and all said the shift lever was too close and too short.
The Kawasaki felt lightest and steered with the most quickness and the most precision. The powerband is broad and the forks were just about right for most of the test conditions. Flighest points were awarded for the super precision the KX provided in the mud. The KX did seem closest to a works machine in detail work.
DIMENSIONS
(in inches unless noted)
FEATURES
Weak point in general was the suspension. both in terms of wheel travel, which is limited, and by the rear shocks, which didn’t have enough control on rebound. Despite the full-floating brake, the rear wheel spent time in the air. The brake system is adequate, but there is too much leverage and not enough suspension for the floater to do its best. There were some personal complaints about the high bars and fat grips, but both are things the buyer can change for himself.
Odd about the Suzuki. Not many months ago the RM250 was the best model on the market. It’s been improved but what with all the newer competitors, the RM somehow has become one of a group.
Which isn’t exactly fair. What the RM has most in its favor is the engine. Because of the case feed reed valves and the way they broaden the powerband. the RM will pull all the way from idle. Western tracks tend to be fast, and all the grunt goes unnoticed. Eastern racers need just this sort of engine.
The RM is probably the most comfortable to ride. All our men gave it high marks for controls, shifting, sense of balance. the rubber-mounted bars and the Suzuki's w illingness to slide. On the minus side the RM's rear brake hopped, the shocks let the brakes get away with it and the seat was too shallow and too hard.
The Yamaha is clearly different from the other three. It’s the monoshock that does most of it. The 1978 version has been tamed and softened and the YZ no longer kicks back. It has good traction, lots of power at the top of the band and w hen it’s on the pipe, it'll drive out of turns with the Honda.
The penalty is weight and a high center of gravity . The weight that keeps the frontend steering when the others are pawing the air makes jumping an effort. And the YZ doesn't turn as quickly as the others. For some riders, this is good. The Honda sometimes doesn't tell you what it’s doing. The Kawasaki will do the wrong thing if you tell it to. And the Yamaha will go its own way and keep the slower rider out of trouble.
It does feel heavy and it can get clumsy in bumpy turns. More vital, it doesn't have power beloyv the peak and if the engine falls oft'its band, you'll have to row back up w ith shifter and clutch.
Now. a hedge for the conclusions. Each of the four rivals builds a competitive motocross racing bike. Each can be tuned and improved. In the right hands, any one of the four can and will win. A racer looking for the best bet would do perfectly we 11 buy ing on the basis of dealer service and support and parts supply. Remember, our Pro could beat our Intermediate no matter w hich bike either man was on.
But. Some of the bikes yvere quicker than other of the bikes. Just because you can’t buy. say. a Honda and w in automatically doesn't mean you can't buy a Honda and trim a couple flabby seconds off your best time on the old yvhatever. If two seconds moves vou from 3rd to 1st. great.
If the winner of this comparison test is determined by kip times, then the Honda got one best time of day and the Yamaha got one best time of day and the Kawasaki came in 2nd on both days. Score that as you please.
For a subjective scoring, our test man yvent to each rider at the end of the second track day. When he was sure the other riders couldn't hear the answers, he asked “If prices were equal, which bike would you buv?”
Each man said. “The Honda.” E9
