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/127128
The main advantage of anti-lock brakes is that t he rider can practice his braking skills with no danger of crashing . BMW/FAG's ABS will be availab le in the U.S. on the K100RSmodei only. , , Riding~ression: BMW/FAG ABS Motorcy~le anti-lock' brakes now a re~lity By Brian Catterson WEST BERLIN, WEST GERMANY, MAR.24-25, BMW an n ou n ced the availability of its antilock braking system (ABS) for motorcycles at a p ress conference held March 24 in West Berlin, Germany. ABS is a proven technology, having been used on cars for the past 10 years and on . I b f h b a i r p ~nes e are t a ~ , . u t BMW s motorcycle u nit IS a 34 production first. H onda is reportedly testing the Bri tish Lockheed electro/ mechanical unit, bu t p roduction is not expected to start u ntil at least 1989. Although BMW began' testing motorcycle ABS when the concept was first developed for cars, it wasn't until 1986 that a prototype debuted a t the Cologne International Bicycle a nd Motorcycle Exhibition. A p ress conference and demonstration was held in Anaheim, Ca lifornia in January of 1987 (thou gh no journalists were permitted a test ride), and a story detailing the workings of the Kugelfischer (FAG)designed unit appeared in the J a n. 28/Feb. II , 1987 issue of Cycle News. The production start then slated for summer of 1987 was delayed until now due to extensive long -term endurance testing. Early units had displayed prob lems with the electronic supervisory system which saw the warning lights flash even though ABS remained operational. Essentially the electrolhydraulic BMW/ FAG ABS works li ke this: A ~ensor monitors ,two 100 -tooth Impulse generator gears on. the front and rear wheels, companng then speed of rotation and informing the computer, located under the seat, when a wheel is about to lock. T he computer then activates one of the two (one. per wheel) p ressure modulators, fitted near the footpegs and weighing 8.4 pounds each. which reduces the.hydraulic pr~ssure in the corresponding brake cyhnder. When the dan ger IS past, the modulat~r restores the brake pressure. T his Wheels fitted with ABS impulse generator gears await installation at the BMW motorcycle factory. process repeats itself three to seven times per second , as long as the rider maintains the necessary brake pressure. In monitoring the performance of the rear wheel, the system also evaluates the front wheel to ensure that an y 'sudden change at the rear wheel caused by throttle reduction or shifting gears is not interpreted by the computer as braking. To preven t the brake lever or pedal from pulsating, as is the case wit h cars fit ted with ABS, a valve interrupts the flow of fluid , p reven ti ng it from re turningthrough the line. ABS does not work at speeds below four kilometers per hour (2.5 mph). Redundant control lines are fitted from each of the wheels, operating ten seconds at a time, alternately. One control line monitors or controls the system while the other is su pervised by th e H ell a central processing u ru t, ,A warning ligh t on the dash a lerts the rider if ABS becomes inoperable, although the standard brakes will conti nue to func tion normally. A dia gno sti c tester can then be used by any BMW mechanic to detect the problem. ABS will be an option on all KlOO models worldwide, bu t will initially be lim ited in the U.S. to the RSmodel only. According to BMW of North America 's Rob Mitchell , there will be approximately 500 of these imported to the U.S. - a ll in a striking white and blue color scheme - to be built during May and June before the factory holidays. T h e option will cost about $1200, and BMW representatives are quick to point out that "ABS costs less than most accidents". That BMW has limited ABS in the U.S. to its sporting fl a gsh ip is surprising, since at the p ress conference Professor Bern t Sp iegel stressed that ABS shoul d no t be used as a pe rformance aid. "Motorcycle ABS shou ld serve as a safety net for emergencies and safe practicing on the road, and should not be a tool used by the rider all the time," he said. Perhaps the system wo uld better fit the RT, whose average touringtype rider may be less skillfu ll than a sport rider, has more invested in hi s machine. and is more likel y to be carrying a passenger. The press were taken to Gatow Royal Air Force Base for a demonstra tion and test rides on March 25th. A runway was divided into five lanes , - four of which were co vered 'with water and one with sand - and each of the j o urn a l ists present were · permitted numerous runs at the sections. Before allowing the .p ress onto the runway, a BMW test rider rode a KlOO with outriggers through th e water and sand with predictable res u lts: t he non-ABS -e quipped machine promptly fe ll o nto an outrigger under bra king. si mulating a certain crash o n a .m achine not so equipped. Regrettably, journa lists were not permitted to ' ri de the outrigger bike. T he test rider then rode a n ABSequipped bike through the hazards and, not · surprisingly. came to a controlled stop. O bserving the test rider at slower speeds. o ne coul d plainly see the spokes of the wheels come to a stop, then start to roll again as the ABS unit cycled. As a testimonial to the effective" ness of ABS, there was no t a single accident, though an American journalist did crash a non-ABS equipped bi ke while comparison tesu ng, H e di d not feel, however. that switching from an ABS-equipped machine to the non-ABS one was responsible for the crash; a q uestion tha t had been on everyone's mind. Whethe r this A BMW test ri der shows what happens when a sudden stop is attempted by a non-ABS-equipped motorcycle on a tractionless surface..