Cycle News - Archive Issues - 1990's

eRIDING IMPRESSION 1993 Honda CBR1000F ~ . .-..The new Honda CBRlOOOF features some c06metic changes but more importantly a Linked Braking System. The unique system activates both front and rear disc brakes simultaneously when either the foot pedal or the handlebar lever is applied. It's similar to the Unified Brake System already found on the Honda Gold Wing. By Kit Palmer elcome back. After a two-year hiatus, Honda is reintroducing its "almost" all-new sport-'touring bike for 1993 - the CBR1000F. We say almost all-new because with the exception of one important new feature, the CBR1000F isn't radically changed from the CBR1000 that was first seen in 1987 and last offered in 1990. It features the usua J cosmetic and styling changes, of course, as well as minute modifications to the motor, and the one very important and innovative feature - Honda's Linked Braking System (LBS). So, what's the Linked Braking System? Well, LBS is an advanced form of the integrated braking systems of the past; integrated braking first appeared in the mid-'20s on the British Rudge. BSA also utilized an integrated braking system as early as the la te '20s, and recent editions of Italy's Mota Guzzi have featured integrated braking. Honda's LBS falls somewhere between a standard braking system and an anti-lock braking system (ABS), yet is very similar. to the Unified Braking System (UBS) that was introduced by Honda on the Gold Wing GL1100 in 1983. But the LBS takes the UBS concept one step further. On the Gold Wing, the VBS uses a foot pedal to operate, in unison, both the rear wheel brake and one of the two front brakes, while the front brake lever actuates both front anchors, but not the rear brake. The LBS on the CBR1000F, however, is designed so that the calipers of both of the dual front disc brakes and the rear disc brake are simultaneously applied when either the handlebar brake lever or foot brake pedal is applied. So what's the advantage of an inle- W 20 grated braking system? According to Honda, studies have shown that riders, experienced or not, faced by emergencies tend to rely too much on the rear brake. This is not good, because the CBR1000F not only benefits inexperienced riders, but the more experienced riders as well, claiming that the LBS is also excellent "insurance" for a tired rider who starts getting a little sloppy • • • ISSln - -In - --------front wheel of a motorcycle plays a much more important part in braking than the rear wheel, especially as the need for hard braking increases. Honda emphasizes the fact that the LBS on the on the controls after a long day in the saddle. Unlike the few anti-lock braking systems found on motorcycles today, Honda's Linked Braking System is Linked Braking System Diagram Hand Brake ...Q.; ..... -"":::=~ -NewPCV c._ _<>ev Front Brakes Rear Brake entirely hydraulically operated, not electronic. For the most part, the concept is relatively simple, but the design and operation is quite sophisticated. Basically, there are only a few major components - dual six-piston caliper brakes up front, a single three-piston caliper in the rear, a secondary master cylinder and the "brains" of the whole system, a Proportional Control Valve (PCV). The rev valve, which is mounted to the frame near the middle of the motorcycle, basically decides how much pressure is needed on the calipers. Using either the handlebar lever or the foot pedal partially activates all three calipers, but the rider controls brake force distribution between the front and rear wheels depending on which control is used. For an example, applying the handlebar lever activates the outer two pistons in each of the three calipers. In this case the front wheel receives a larger proportion of braking force (since there are two calipers up front). On the other hand, applying the foot pedal activates the center pistons in each of the two front wheel calipers, and all three pistons in the rear calipers. Therefore, the rear wheel receives a larger proportion of braking force. At extremes, if the front brake lever is solely applied, then the front wheel will lock before the rear wheel (as it should), and when the rear brake pedal is solely applied, then the rear wheel will lock before the front. If both brakes are applied simultaneously, then the LBS works as is if both brakes were properly applied for maximum braking power on a traditional braking system. The LBS design came about when Japanese engineer Mr. Tsuchida was given the assignment from Honda to design a non-ABS braking system that

• Cover