The Motorbike Archives

You see, the motorcycle I'm referring to is Kawasaki's KDX175 enduro. And as you are about to read, it routinely works some pretty impressive miracles in the dirt. It lets—maybe it even makes—beginners ride like experts and experts ride like beings from some planet where everyone is Dick Burleson. Now, if that's not magic, what is it?

Whatever it is, the KDX175 oozes it from every nook and cranny. Take my word for it. Because after 300 miles in AMA national championship enduros and nearly 500 additional miles of WFO test riding on two of them, I know. I've tried my damndest to break them, to fall off of them and to make a fool of myself on them, but so far I haven't had much success. Matter of fact, these 175cc Uni-Traks are so good that people around here think that I actually know what I'm doing on an enduro bike. In that respect, riding a KDX175 has done more for my image than a personal press agent.

You might have read high praise for this motorcycle before, probably in tests of the original model earlier in the year. If so, you might be surprised to learn that the '81 version is even better. Not so you'd notice at first glance, yet Kawasaki apparently found a way to dip the new KDX into that special magic potion one more time, for it is, without question, a slightly better motorcycle in virtually every way.

Take the engine, for example, a 173cc reed-valve two-stroke that's been conspicuously improved with just a few inconspicuous refinements. Like the window that's now machined into the intake skirt of the piston, extending the effective open duration of the intake port and the booster transfer port without requiring any change in their actual dimensions. Translation: better performance from the middle of the rpm range upward. Additionally, the fat center section of the exhaust pipe has been enlarged in diameter to increase its interior volume. That also nets more power in the top half of the rpm scale. And although the compression ratio remains unchanged at 7.6:1, the squish band in the cylinder head is reshaped to improve combustion characteristics at all rpm.

What this means out on the trail is that anyone who liked last year's engine will absolutely love this year's. Not that the original motor drew much criticism; most people were amazed at how much power the "little" 175 produced at any and all rpm. It was just short of a trials motor at very low revs, typically enduro-torquey in the midrange and right in Motocross City on the top end. Yet Kawasaki claims the '81 engine has three more peak horsepower; and the fact that the new peak is at 9000 rpm, 500 revs lower than last year, is your first clue that the rest of the rpm range hasn't suffered because of that increase. The truth is, there's a noticeable improvement in responsiveness at medium rpm and slightly more crisp running at low revs.

I learned first-hand about the wonderfulness of those improvements when, after having logged hundreds of miles aboard a 1980 KDX175, I debuted an '81 in the Jack Pine National enduro. Time after time in that demanding 200-mile event, the powerful-but-tractable engine pulled me out of potential trouble when I made a riding mistake. Sometimes it lugged down to ridiculously low rpm like a good 250 when brain-fade made me use the wrong gear on a steep uphill; other times it continued to pull effectively at what sounded like nine million rpm when my flailing feet couldn't even find the footpegs, let alone the gearshift. No matter how unreasonable my request, the engine was willing to comply. Sure, the 1980 KDX had been exceptionally forgiving, power-wise, but the new engine has two-stroke compassion down to a fine art.

Don't, however, credit all of that to improvements inside of the engine; some minor changes in exterior systems, such as the carburetor jetting and the air filter, have done their part to boost the get-up and-go. The filter's cake-shaped foam element now offers more usable filtering area, even though it's more squat than before. The shortness keeps the circular part of the element from pressing against the inside of the left sidepanel, thus adding that area to the available filtering surface. And while the increase might not be discernible when the foam is clean and freshly oiled, the added breathing is readily apparent in the way the engine continues to pump out good high-rpm power when the element is wearing 100 miles of enduro grunge.

That broadened power curve also has effectively remedied one more flaw in the '80-model KDX: a sizable ratio gap between second and third gears. Last year's engine sometimes 'had trouble spanning that gap in heavy mud or up certain hills; but the wider powerband on the '81 usually handles it with ease, even though all of the ratios are identical to last year's. And if you do reach a point where one gear is a bit too low and the other a tad too high, you generally can urge the KDX up into a stronger segment of its powerband by slipping the clutch—in the taller of the two gears, of course—to gather speed. The most amazing thing is that the clutch accepts mile after mile of that kind of abuse without a whimper. I deliberately (and needlessly) used that tactic on just about every one of the many uphills in the Oregon National aboard a 1980 KDX, but the clutch adjustment didn't fluctuate even one millimeter all day.

Indeed, that 125-mile enduro was one I'll never forget, although for reasons having nothing to do with clutch free play. For one thing, while several hundred of us were following little red arrows through the Oregon woods, Mt. St. Helens was blowing her stack for the first time just right down the road. Nothing like a volcanic eruption to commemorate your first enduro in more than eight years. But as awesome as that spectacle was, the KDX175 showed me something almost as impressive that day. It showed me that all of this business about 175s being too small for big people to ride competitively is pure bull. By mid-event I had lost over 40 minutes in two massive bottlenecks, and yet—at six-foot-one and over 200 pounds at the time—I was able to get back on schedule and zero the last three checks. Not because I'm one of those Burleson-clone riders. Not because I cheated or cut the course. But because the motorcycle I rode that day was, as I said before, magic.

I hear some scoffing and snickering out there. Meaning that, obviously, you've never ridden a KDX175. If you had, you'd know what I'm talking about. You'd know that this innocuous-looking little Kawasaki is one of the finest-handling and most-forgiving enduro bikes ever to leave its knobprint in the woods. So much so that you or I or virtually anyone can get seriously and outrageously berserk on one and live to brag about it. And that's why I was able to make up so much time in Oregon. In fact, the worst thing about my maniacal ride on the KDX that day was that I couldn't stand at the side of the trail and admire myself while I was getting away with such uncharacteristic craziness. Like I said, it's a magical motorcycle.

There are, of course, numerous reasons why. One is that the KDX has an unusually long wheelbase that helps give it the straight-line stability of a Greyhound Scenicruiser. That's mostly because the rear ends of long motorcycles tend to do things slowly—things such as skitter and sidehop. Better yet, the KDX does them not at all. Furthermore, the bike is comparatively front-heavy; and while that, in conjunction with the long wheelbase, makes wheelies more difficult, it also discourages the front wheel from being easily deflected off-course.

Not that the KDX can't react in a hurry; it most assuredly can, for the steering geometry is very quick and the center of gravity—due, in part, to the physics of the Uni-Trak rear suspension—is relatively low. So although the KDX is stubbornly prone to going in a straight line when acted upon by outside forces, it will change direction immediately when ordered by the rider.

I experienced the bike's entire range of handling versatility in the Jack Pine, where one minute the drill was to zig-zag between closely spaced trees in low gear, and the next it was sandy whoop-dee-doos at the top of fourth and fifth gear. These examples represent the extremes of the enduro-handling spectrum, yet the KDX dealt with both conditions exceptionally well. When the situation called for full-lock steering, the bike seemed as though it had been specifically designed for it. But it also felt ideally suited for high-speed rough-riding, for it absolutely refused to get sideways or out of shape on the cobbiest and fastest of trails.

Not to be overlooked, though, is the contribution the suspension makes to the KDX's good trail manners. Basically, things in the leading-axle fork and unreservoired-shock department are almost the same as last year, but there are some improvements. The fork, for instance, is now fitted with air caps, and while everything else about it is unchanged, the air-assist allows a greater range of tunability to suit various riding conditions and styles. The Uni-Trak shock, too, offers the same rates of springing and non-adjustable damping as the original KDX175, but there's a new shock body and single-rate spring that are lighter in weight. Lighter and stronger also is Kawasaki's description of the bike's imA "torque arms," as they're called, the vertical struts that connect the steel swingarm to the beefy rocker arm beneath the seat.

Despite the improvements, I was able to bottom the rear end of both bikes on some of the more horrendous whoops and bumps, even after I had starved myself down to 185pounds. That bottoming was for a reason, though, since the rear spring rate was selected to accomodate average size 175-class riders—those between about 125 and 165pounds would be my guess. Otherwise, the rear ends on both bikes behaved impeccably on all types of terrain, ranging from the stutter of little chops to the slam of giant moguls. My sole displeasure with the 1980 front suspension, too, was its tendency to bottom on occasion; but pumping about four to eight psi of air into the '81-model's tubes left me with nothing to snivel about, fork-wise.

The resultant ride, therefore, is plush, but I do have one complaint about the bike's overall comfort: The distance between the handgrips and the footpegs is too short. That's easy to understand, since the KDX175 is, essentially an overbored KX125 motocrosser. Today's motocross machines have very short gas tanks and extreme forward riding positions to keep the rider's weight on the front wheel for better steering; and that situation is further complicated on 125cc MXers by the fact that the average rider in that class is quite small. And so my long-limbed body is never completely at ease when it's up on the pegs, especially when going up steep hills. I have to devote a lot of energy to just hanging on that would be better used to steer the motorcycle. If you're five-foot-eight or less, though, forget everything I just said.

Truthfully, the stand-up position is my biggest gripe about the new KDX175. Oh, I could whine about how the long torque arm on the full-floating rear brake is vulnerable to damage or that the brake itself is a bit too touchy. I could point out that the brakepedal ought to have a folding tip like the gearshift's. And if I wanted to pick a few ISDT-caliber nits I could note that the KDX's wheels aren't exactly of the quick-change variety. But when I weigh the importance of these few items against the utter competence of the bike's overall performance profile, I haven't got the nerve to really complain about them.

Besides, it's not as though Kawasaki hasn't made an honest attempt to improve the KDX. To help extend chain life, for instance, there's now a plastic chain and on the swingarm to keep the knobs from slinging dirt on the No. 520 DID. And to prevent the shift lever from being sawed in two when the chain does develop excess slack, the lever has been reshaped for more clearance where it passes under the chain. There's also a wider plastic skid late a longer and wider rear fender, and even a toolbag behind the seat—not a particularly good bag, but better than no bag at all. And Kawasaki even found a way to keep the stickers from peeling off of the plastic gas tank.

If those improvements seem trifling to you, if things like windows in pistons and shorter filter elements and stickers that stay stuck leave you with the impression that the 1981 KDX175 isn't much better than the 1980 model, you're right; it isn't. But that's not a put-down of the new bike; it's a tribute to the intelligent design of the original. Which proves that if it's done right in the first place, it's hard to improve the second time around.

Make no mistake, then: Kawasaki did it right the first time. That's why the KDX was and is magic. That's why in more than 450 consecutive miles on them, including both National enduros, I didn't fall down once. And believe me, I do fall down. A lot, at times. But aside from when I laid the bike on its side once to help another rider, the handgrips never touched the ground. And with me riding, that's magic.

In all fairness I have to admit that "magic" almost is a cop-out in this case, a word that describes what the bike does, not what it is. But there's another single word description that tells you everything you need to know about this motorcycle. When you consider all of the things the KDX175 can do how well it does them and the incredibly wide range of riders for whom it can do them when you take into account all of the offbike factors such as price and reliability and the like, the picture—in my mind, at least-is crystal clear: The KDX175 is the best all-around enduro motorcycle built. And not just at the present time.

Ever. 

RIDE REVIEW

Little bikes are for kids as far as I can see. And anything less than a quarter-liter is usually less than enough for me. Normally, I wouldn't even seriously consider a 175 big enough for my 190-pound frame, so imagine my surprise at liking the KDX. From the first day in the workshop when I threw a leg over the tall saddle I felt at home. The bike was light and manageable, but somehow it didn't feel at all like a kids' machine. The first ride was just as impressive. This was not kids' stuff but an adult toy that dragged me everywhere I wanted too. From the steepest hill to the tightest trail I enjoyed a second childhood.

So much pleasure could not come from a single source. Neither the frame nor the motor alone would have been enough to convince a grownup like me that 175s are not solely for kids. The KDX convinced me with a perfectly balanced package. The engine pulls like no 175 I have ever ridden, and the clutch will absorb just about any abuse. Better still, the suspension will not pass along any abuse to the rider. It doesn't even give cause for concern, because at any speed the KDX is stable. Even in the woods it is manageable.

After a few days of hard riding I am prepared to admit that there is some measure of the child in each of us. And the bit inside me wants a KDX175.—David Dewhurst

It's easy for me to be contemptuous of 175cc enduro bikes. I know they offer a combination of light weight and full-size power that should make them the right choice for 90percent of all enduro riders. But as much as I acknowledge the wisdom of the concept, the execution always has bothered me.

Basically, I get tired of keeping track of a scaled-up 125 motocrosser on the trail. Every chipmunk dropping deflects the front wheel, so I'm weaving through the woods when it's not necessary. And the powerband is so narrow that the shifting required for a 50-mile loop leaves me bleeding from the ears.

So my appreciation for the KDX175 doesn't rest on its resemblance to other 175s. Instead, I'd choose this bike because it deals with rugged terrain with the same unflappable cool as a Husky 250WR. It's got a full-size chassis that lets me ride the shortest distance between two checkpoints. Meanwhile, the engine spins out that perfect combination of low-end thrust and top end horsepower that Yamaha has sought without success for three years.

Sure, I realize that the KDX is a great 175cc enduro bike. It even says 175 right on the sidecovers. But in its heart, this bike knows it's a 250. And when you come right down to it, I do, too.—Michael Jordan►

GETTING WITH THE PENTON PROGRAM

When Jack Penton formed True Sport Engineering at the beginning of 1980, he had one immediate objective: to surround himself with some of the best enduro riders and mechanics in the business. The reason was that Kawasaki had retained his services to field and ride on a team for national enduro and ISDT competition. And Kawasaki's mandate to Penton was clear: prove that the company's enduro bikes were winners, even if they needed large-scale modification.

Penton's first experience with a KDX175 indicated that his job wasn't going to be difficult at all, not as far as that motorcycle was concerned. "When we first started with the stock 175, we were impressed," claims Penton. "It didn't appear that we would have to do any extensive modifications at all to make it at least as competitive as any other enduro bike. Our initial impressions proved accurate, too, for the KDX didn't need much fiddling to be a national-caliber competitor."

Basically, what Penton and his crew do with the KDX is replace a few standard parts with better-made--and more expensive—units. This motorcycle, like any other, is manufactured under the watchful eye of corporate bean-counters, and all that Penton does is to put the competitive edge back in that the cost-per-thousand guys took out. For instance, True Sport mounts state-of-the-art knobbies at both ends, usually a 3.00x21 4-ply Hi-Point tire up front and either a Hi-Point 110/90 or a Metzeler 4.00x18 in the rear. TDI sprockets that retain the standard gear ratio are used, and the stock brake shoes are kept, but replaced with every two or three nationals.

Cosmetically, True Sport installs KX125 motocross-style side number plates on its KDXs "just to make 'em look trick." And a Hi-Point front fender is bolted in place due to the stocker's tendency to bend and flap when heavily mud-laden. A straight-pull throttle and Six-Day-type levers, all by Magura, are installed and hooked to Terrycables. And either the standard handlebar is cut down to about a 30-inch width or a Hi-Point bar is used by the Big Green Enduro Team.

You would think that Penton's KDX175 engines would be terribly trick. But they're not. "We tried a lot of different porting specs and liners and carburetors and pistons and rings," said Penton about his quest for an improved powerplant. "But after all the research and modifications, we came back to stone-stock. It works the best."

The engine didn't completely escape the True Sport touch, however. To facilitate easier on-the-trail engine repairs, all of the Phillips-head case screws were replaced with straight-slot screws from Metric Multi Standards of New York. An in-line fuel filter and a Hi-Point air filter were installed, and the skid plate was discarded because mud tended to accumulate inside of it. The cure for an exhaust-system leak that often crops up on KDX175s was found to be either the replacement of the pipe's rubber gasket every few races or else modifying the header pipe to accept two gaskets. And True Sport's final touch is to mount enduro timekeeping equipment from Clairemont Cycle Supply.

Other than those few modifications, Team Kawasaki's KDX175s—including Jack Penton's own bike—are frighteningly close to stock. So if you want to zero all of the checkpoints just the way that he does, get a pair of size 32 Hi-Point Kawasaki pants, size 9 boots and size 9 gloves (Jack's father, John Penton, owns Hi-Point Accessories, if you hadn't already guessed), a white Kawasaki jersey and a green 71/2 Bell Moto III. Then curl your hair and grow a moustache, and you'll be just like Jack Penton—except for the talent, the stamina, the experience and most of all, the blazing speed.■