The Kawasaki KX100 and KX85 are dirt bikes for beginners. The KX85 allows youngsters to move up from the 50 cc class to get used to the extra adult-like crisp throttle. The KX100 is the next step toward an all-out adult bike for the novice preteen rider. However, these dirt bikes are not kiddie rides. The KX100 in particular is a training bike for more serious riding. It features power not to be trifled with.
The KX85 recalls the old-school Kawasaki KX80 and Suzuki RM80 that held court among the lightweight sub-100 cc class of bikes. The Kawasaki KX85 is essentially a bored-out version of the KX80 with a bigger power band. Kawasaki designed the KX100 to ready young riders for the KLX125 and the 250 cc class of off-road bikes. The KX85 and KX100 have the same look and feature similar power and handling, although their dimensions differ slightly and the KX85 has a lower center of gravity to accommodate smaller riders with less agility.
A 99 cc liquid-cooled engine powers the KX100. Its most apparent difference from the KX85 is its superior low-end torque and quick throttle response, thanks largely to the KX100’s 28 mm Keihin carburetor. Both bikes, however, transmit power to the wheels via a six-speed transmission. Like the KX100, the KX85 has a single-cylinder two-stroke engine. It displaces 84 cc. It also has the 28 mm Keihin carb, but its small displacement limits the low-end torque. And for good reason. The less torquey KX85 prevents inexperienced riders from popping the throttle and finding themselves flat on their back on the trail. That said, both bikes have a relatively high compression ratio, 9.6 to 1.
The 2012 KX85 clears the ground at 13.4 inches, while the 2012 KX100 has a ground clearance of 15 inches. With the frame lower to the ground, the KX85 has a lower center of gravity. This may compromise Its overall agility, but it makes the bike more manageable for youngsters. Long-legged teenagers may find the KX85 awkward. The KX100 is more versatile in rough terrain, particularly on hill climbs and rocky trails. Aside from the minor differences in dimensions, the KX100 and KX85 have virtually identical suspension components. Both have a 36 mm cartridge fork with a 20-way compression damping adjustment capability. In the rear is a fully adjustable spring preload Uni-Trak single shock with rebound damping. The front and rear have 10.8 inches of travel.
The 2012 KX100 is best characterized as the KX85’s slightly bigger brother. Its wheelbase is 50.8 inches; the overall length is 75.2 inches. It's 28.9 inches wide and 43.5 inches tall. The seat rides 35.3 inches off the ground. The curbside weight is 156.5 lb. The KX85 is a shrunken version of the KX100, but not by much. It has a 49.4-inch wheelbase and nearly 4 inches less length than the KX100. It’s the same width as the KX100 but 2 inches shorter, with a seat height of 33.1 inches to accommodate younger riders. At 152.1 lb., the KX85’s curbside weight is also more manageable for beginning riders.