MXA TECH SPEC: 10 THINGS YOU NEED TO KNOW ABOUT THE 2020 KAWASAKI KX450
(1) Forks. Every MXA test rider loved the feel of the 2020 Kawasaki KX450 Showa forks. They were plush, comfortable and, best of all, followed the ground better than the previous TAC air forks. The slower the test rider, the better the forks, but as the test rider’s speed increased, the forks quickly became too soft. Our quick fix was to keep the stock 5.0 N/m spring in one leg and put the optional 5.2 N/m spring in the other leg. National-speed Pros will need the 5.2 springs in both legs.
(2) Clutch. Although the 2020 KX450 clutch is hydraulically activated, the clutch itself isn’t very good. We recommend removing the miniaturized fiber plate, ring-like judder spring and flat spacer, and replacing them with one additional full-size clutch plate. Additionally, we run three stiffer Pro Circuit clutch springs. The leverage ratio of the stock clutch lever does not generate enough hydraulic piston movement to release the clutch fully. When your clutch lever hits the two fingers that are still on the grip, the clutch is actually slipping. Even though you think you’ve pulled the clutch in, you haven’t. We went to the guy who builds Eli Tomac’s clutch lever, and he told us to run an ARC Flip-Chip-equipped PowerLever. It allows you to change the leverage ratio and make the clutch disengage at six different points on the lever pull.
(3) Rear brake. The jumbo-sized 250mm rear rotor is too touchy. To lessen the grabbiness, we chamfered the edges of the rear brake pads at an angle to allow the pads to slide onto the rotor more efficiently and to downsize the pads’ surface area. We also removed the black plastic rotor guard from under the swingarm, because it blocks airflow to the rotor (Honda removed its guard in 2020).
(4) Rear brake pedal. The rear brake pedal can be adjusted upward but not downward. To cure this, we hacksawed three threads off the bottom of the threaded master cylinder rod to give the pedal more downward free play; that way, a boot can touch it without locking up the brakes by accident.
(5) Maps. The stock green coupler offers the best ECU map. It is significantly stronger than the mellower black coupler and a lot less hyperkinetic than the aggressive white coupler. If you compare the black map to the green map, the black map gives up 1 to 2 horsepower. As for the aggressive white coupler, it does not produce more horsepower than the stock coupler, just a crisper feel.
(6) Grips. Kawasaki’s black grips look like the real thing, but don’t fall for it. It is a trick. Any aftermarket grip is twice as comfortable as the stock KX grips.
(7) Plastics. Kawasakis have very brittle plastic. Roost cracks the fork guards. The front number plate cracks down the center, and the elongated arms of the radiator wings crack vertically. Order aftermarket plastic. It is much more durable.
(8) Airbox. To get to the air filter, you need both an 8mm and a 10mm T-handle. That is one wrench too many. Additionally, the nut plate behind the top bolt falls out of the fender when you loosen the bolt. Finally, the airbox is very small and the design is very weird.
(9) Chain roller. The lower chain roller—the one under the frame that keeps the chain from whipping as it spins off the countershaft sprocket—self-destructs in an amazingly short amount of time. Considering the chain roller issue and Kawasaki’s long-term problems with its rear chain guide, you should order TM Designworks parts on day one.
(10) Overheating. We run a 2.0 kg/cm2 Twin Air Ice Flow radiator cap in place of the stock 1.1 kg/cm2 to keep the radiator from spewing fluid.
MXA PRODUCT SPOTLIGHT: JUST1 MOTOCROSS RACEWEAR
Although we haven’t seen much of Joey Savatgy in his Just1 gear this season, because of his heel injury in Australia, he is back riding now and when the season starts up again he plans to be on the line. The same holds true for Just1 riders Tommy Searle, Tanel Leok, Ken DeDycker, Michele Cervellin and Darian Sanayei. Here is a quick look at Just1’s 2020 gear line.
JUST1 J-FLEX GEAR
JUST1 J-FORCE GEAR
For more information go to www.us.just1racing.com
HAVE YOU SEEN THE MAY 2020 ISSUE OF MXA? THE BEST OF AMERICAN MOTOCROSS
If you subscribe to MXA you can get the mag on your iPhone, iPad, Kindle or Android by going to the Apple Store, Amazon or Google Play or in a digital version. Even better you can subscribe to Motocross Action and get the awesome print edition delivered to your house by a uniformed employee of the U.S. Government. You can call (800) 767-0345 or Click Here (or on the box at the bottom of this page) to subscribe.
THE IRON GIANT FALLS TO THE VIRUS: 2020 ERZBERG RODEO CANCELED
WORKS BIKES YOU MAY REMEMBER: THE MX KIED’S 1991 KAWASAKI KX125
“Kawasaki hired me with the promise and understanding that I would win the championship for them,” said Mike. “I felt a lot of pressure, but they gave me 100 percent backing and built the bike exactly the way I wanted it.” Kiedrowski’s mechanic was Shane Nalley, with Rick Asch doing the suspension and Jim Felt building the engines.
The “MX Kied” didn’t have the fastest bike on the track. In fact, Mitch Payton called it a “slug,” but it suited Mike perfectly, and Kawasaki modified the production-based machine extensively. Some of the engine modifications included stuffing the crank to increase crankcase pressure and filling the transfer ports with epoxy so they could be completely reshaped. Engine weight was shaved by using magnesium primary and ignition covers and milling material off the clutch and transmission components. The suspension was “works Kayaba” and fine-tuned by Asch with an emphasis on the high-speed compression control that Kiedrowski demanded.
As the 1991 season neared its conclusion, Kiedrowski would go on to win the championship over Guy Cooper by 16 points, even though Cooper won the five 125 Nationals to Kiedrowski’s four (Red Bud, Axton, Southwick and Millville). Mike raced the same bike to victory at the 1991 Motocross des Nations.
Works bikes are almost unobtainable because the factories usually destroy them. Development costs, even on production-based machines, can easily run into six figures. The value of this machine is estimated at $50,000. Kawasaki gave Mike Kiedrowski his title-winning bike as a reward for a job well done. It sat in Mike’s living room until Mike’s wife Kim remodeled the house and relegated the KX125 to the garage. Mike lent it to theTom White’s Early Year’s of Motocross Museum.
From a distance, the Kiedrowski works 125 looks quite similar to a stocker, but look close and you will see a magnesium upper shock mount, mag triple clamps, mag outer cases, factory hand-built pipe and Kayaba works suspension. There is even a welded brace on the throttle-cable exit.
MXA FIRST RIDE VIDEO: THE EXOTIC & RARE 2020 TM 300MX-FI FOUR-STROKE
MXA PRODUCT SPOTLIGHT: PRO CIRCUIT “THE GREAT RACE” RACE T-SHIRT
A new shirt has landed in the Pro Circuit warehouse and the boss himself, Mitch Payton, is displayed on the back design. Printed on a comfortable blank with quality inks, The Great Race Tee will definitely have hearts racing for the ones who enjoy an occasional car burnout as Mitch lays down the power in his old Anaheim Husqvarna van.
This tee was originally handed out in limited quantities on the day Mitch received the Edison Dye Lifetime Achievement Award, but now customers have the chance to score one as well. Retail price: $21.00 at www.procircuit.com
CANADIAN NATIONAL MOTOCROSS CHAMPIONSHIP MOVED, BACK RESHUFFLED & TRACKS CHANGED
2020 CANADIAN NATIONAL CHAMPIONSHIP
June 7…Wild Rose, AB
June 14…Drumheller, AB
June 14…Dorva, AB
June 21…Kamloops, BC
June 28…Regina, SK
July 12…Gopher Dunes, ON
July 19…Sand Del Lee, ON
July 26…Moncton, NB
Aug. 2…Deschambault, QC
Aug. 16…Walton, ON
THE CARS THAT NEVER CAME TO THE LOCAL AUTO MALL
You may have heard of the Maico 501, but don’t confuse it with the Maico 500. Yes, it was an air-cooled two-stroke, but the engine wasn’t made by Maico, but by airplane manufacturer Heinkel. If you had been in the market for a car back in the day, would you have bought a Maico? Maico marketed their line of small cars from 1956 to 1958 (which they inherited when they bought the defunct Champion car company). The Maico 500 was powered by a 452cc, twin-cylinder, 18-horsepower, water-cooled, two-stroke Heinkel engine. The two-door car could hold four people, but it was by no means roomy. Warranty issues doomed the car and production was stopped in 1958. Maico went out of the automobile business in 1958, but continued to manufacture motorcycles through 1986.
1972 GREEVES INVACAR
In 1948, Bert Greeves adapted a motorbike to help of his paralysed cousin, Derry Preston-Cobb, get around town. The idea caught on and, with British government support, Greeves started building the Invacar for soldiers disabled in the Second World War. The British Ministry of Pensions distributed Invacars free to disabled people from 1948 until the 1970s. Early vehicles were powered by an 147cc, air-cooled Villiers engine, but near the end of their run, the Invacar’s had 500cc Puch four-stroke engines. The body was made of fiberglass and most of them were the same shade of blue. Greeves sold thousands of Invacars which helped finance his motocross bikes and race teams.
1991 YAMAHA OX99
Yamaha has a long history in auto manufacturing. In 1967 Yamaha built the engines for the Toyota 2000GT (the first Japanese Super Car). In 1984 Yamaha was producing engines for the Ford Motor Company. And, most significantly, Yamaha had an engine in the 1989 Formula 1 West Zakspeed cars, but what you don’t know—is that Yamaha built a Super Car based on what they learned in F1. Most notably, using the 3.5-liter V12 engine.
The 1991 Yamaha OX99 two-seat sports car (with the passenger in tandem to the driver) featured a wing-like front spoiler, aircraft-style cockpit and protruding engine scoop. Top speed was 210 miles per hour via a six-speed gearbox. To keep it secret, Yamaha tested the OX99 at night at the Millbrook Proving Ground in England (with F1 GP driver John Watson as a test driver).
Only three OX99-11’s were built.
Only three OX99s were built (a raw aluminum one, a black one and a red one). Yamaha had plans to develop the OX99 as a production car, but in 1994 that idea was discontinued.
1937 BSA SCOUT
BSA actually starting making cars in 1907, but stopped and started several times (1914, 1921 and 1932). The last BSA car was produced in 1940. Their best known car was the BSA Scout. The Scouts came as two-seat sports cars, four-seat tourers and two-seat coupes. It was a front-wheel drive car, manufactured and sold by a subsidiary of the Birmingham Small Arms Company. It was launched in 1935 with a three-speed tranny, four-cylinder layout, 1075cc engine (out of the previous BSA three-wheeled car). It had a rakish looking body with cut-away doors, luggage space in the tonneau, motorcycle-style fenders and a single-piece windshield.
2017 BULTACO LINX
At the 2017 International Motorcycle Show in Milan, Bultaco unveiled the Linx—it’s first automobile. The Linx hits the scales at 1870 pounds and production is expected to be less than 50 cars per model year. The price will be 100,000 euros ($109,000). The powerplant is expected to be a 2.0 liter turbo from either Audi or Volkswagen. The rear engine roadster does not have a windshield, side windows or roof. And yes, the exhaust is from Akrapovic. There is talk of turning the Bultaco Linx into an all-electric car.
1970 MONTESA FORMULA 4
Montesa never made a real car and the only photo of their British Formula IV race car comes from a 1970 newspaper clipping. The driver was Tony Brise, who’s father was the British Montesa importer. Brise, who at the time was a British karting champion, won the 1970 British Formula IV championship in a car equipped with a 250cc Montesa engine. Tony Brise would eventually become a Formula 1 driver. Tony was the protege of World Driving Champion Graham Hill, who was the only driver to have won the Triple Crown of racing — Formula 1 Championship (1962 & 1968), Indianapolis 500 (1966) and 24 Hours of LeMans (1972). The 23-year old Brise raced the Formula 1 series in 1975 for the Embassy-Hill team as Graham Hill’s fill-in driver — and had several top ten finishes. Sadly, Brise was a passenger in a plane flown by friend Graham Hill that crashed short of Elstree Airport (12 miles north of London) on November 30, 1975. Hill, 46, had retired from Formula 1 racing five months earlier.