Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/126943
The new rear disc brake has excellent feel and is well protected. An all-new motor gives the 1987 Honda CR125R even more horsepower than last year's CR. It really hooks up. Test: Honda CR125R When being the best isn't enough By Kit Palmer A true sign of success isn't so much reaching the top but staying there once you've reached it. That's pretty much' Honda's philosophy behind the company's popular CRI25R. The 1986 Honda CRI25 was undou btedl y the best small. bore motocrosser on the track, . 10 fact, the motorcycle was so good, it could've survived another year relatively unchanged and still be a competitive mOlOrcycle, But noool Honda wasn't about to stand back and take a chance at letting the competition catch up, so 1987 sees, not only minor refinements, but also some radical changes to the new CRI25R. What made the 1986 CRI25 stand out so far i1bove the competition was Honda's superior molOr. Its superwide powerband, strong low-end pull,- trench-digging midrange and topend speed couldn't be r~~llched bya!1Y of the CR's compellllon. Desplle havinga near flawless I25cc mOlOr in 1986, Honda gambled and designed an all-new mOlOdor 1987 in hopes of finding even more horsepower. First of all, the two-stroke, watercooled engine has a 5mm longer stroke than before and a larger I 24.5cc displacement. With this, the compression ratio has been increased from 8.4: I to 8.8: 1. But the two most significant changes 10 the motor are the switch to a case reed-valve induction system, formerly a straight-shot, piston-port reed-valve, and a redesigned exhaust power-valve. Going to the case reedvalve design, says Honda, gives the CR better torque and more eHicient gas flow. Complementing this change is a new ATAC exhaust valve that now uses a drum-type valve instead of a butterfly valve. The ATAC, which is located above the center-port exhaust champer, is larger in size and carries 45cc more exhaust volume. Another advantage in this new drumtype power-valve is that it's less restrictive, and the design is more simple, making it easier to maintain. A new exhaust pipe is used; it comes with a easier-to-rebuild aluminum silencer. To achieve a heavier flywheel effect, the crank is slightly heavier; .14 kg to be exact. Other motor changes incl ude a new ignition coil that produces longer spark duration; a stronger clutch assembly (including an easyaccess clutch cover); slightly taller overall six-speed transmission gear ratios; a fIat-side air filter that keeps it from spinning 0(£ in the airbox, and a new outside-the-cylinder water pump and ATAC linkages. ~uspensio.n and chassis changes to the CR are found in abundance. Last year's CRI25 had the best front fork assembly in its class with the cartridge damper system, which was made by Kayaba. This year's fork is Showa-made (with the cartridge design) and is the'exact saine type that's found on the bigger CR250 and 500, but has slightly less travel at 11.8 inches. The rear Pro-Link, single-shock suspension system uses an all-new Kayaba shock with a piggyback reservoir. The shock is designed almost exactly the same a the Showa shocks used on the CR250 and 500. Compared 10 last year's unit, the Kayaba has a 4mm larger body; different damping characteristics; is a nodi zedcoated for longer shock and oil life, and has a slightly heavier spring rate. The Pro-Link linkage lever ratios are the same as last year's. Both the fork and shock are fully adjustable with external compression and rebound damping settings. The frame geometry is the same as last year's CRI25, but the engine is mounted slightly lower and farther forward in the frame to improve and lower the bike's center of gravity. The aluminum swingarm is all new for '87; it's lighter, stronger, and where the rear axle slides through is much narrower. In fact, the rear axle length is two inches shorter. Attached to the new swingarm is a new chain guide assemb'ly that is reinforced by an aluminum guard. The rear sprocket is now heat-treated 10 improve strength. One of the biggest changes to the chassis is the switch from a rear drum brake to a hydraulic disc system. The single-piston caliper is mounted on top of the swingarm and is protected by an aluminum guard. Up front is a double-piston caliper disc brake that is actuated through a steel-braided hose. Dunlop tires are used at both ends. Other chassis changes include an extended seat; handlebars that are mounted 5mm lower; a redesigned but same-size gas tank, and reinforced footpegs, On the track Our first experience on the new CR was a shaky one. We couldn't get the motor to clean out, as if it was carbureted too richly. We fouled two spark plugs right off the bat, and before we started fooling around with jetting, we found the crux of the problem to be the Ii ttle plastic cover on top of the airbox that comes stock on the CR; the cover that's designed to be used in extremely wet conditions. Obviously, the bike was jetted at the factory without the airbox cover installed, causing it to run too rich. We immediately tossed the restrictive airbox cover, and our CR hasn't fouled a plug since. Horsepower is still the Honda's strongest feature. The powerband has the same characteristics as last year'!,