Cycle News - Archive Issues - 1990's

eTECHNICAL Honda sn I00 ABS·res ~ (Left ) The rearwheel senso r sends information to bo th the ABS and T CS comp uters. (Ri gh t) The T racti on Co nt rol System kep t the rear wheel tracking , straight when accelera ting in sand. (Below) T hree modes of ABS operation are design ed to closely maintain ideal bra king pressu re. ~ III OPEN - CLOSED Pressure DECREASE Ho nda system works smoother than BMW's system that we had previously tested since the brake pressure remains at a co nstant level. In the BMW 's system , wh en whee l lock is detected the ECU activates the modulat or s to co ntin uo us ly interrupt h ydrau li c pressu r e in th e brak e cyli nder-unt il th e risk of lock has been eliminated. Th is co n tin uo us interruption makes the BMW 's suspen sion co m press a nd release more dramati cally so it seems to lurch to a halt. Honda 's ECU co mpu ter runs a selfd iagnost ic p ro gram to chec k ABS fun cti ons every tim e th e ignition key is turned o n. It al so chec ks th e o perating status of th e main hydraulic Pressure HOLD Pressure INCREASE co m po nents, a nd if a ny problem is detected a n indicator ligh t - po wered by two bulbs, o ne of wh ich is a backup, is illum in ated o n the dash a nd the system a utomatica lly swit che s over to co nven tio na l o perati on . A ba ckup piston prevents co mplete bra ke system failure if th e mod ula to r's hydra ulic pans are damaged. J ust as Honda 's ABS enha nces safety under hard bra kin g , t he Traction Co ntrol System is desig ned to help the rider acce lera te safe ly on slip pe ry surfaces. The TCS sha res th e same rear-w hee l sensor used for the ABS, but has its o wn electroni c cont ro l unit wh ich p ro cesses informa tio n o nce every 1/i 00th of a second. Wh en rea r- Honda's high desert I1roving_grounds M 18 uch of America n H onda 's ne w ca r a nd motorcycle testing takes place a t their p roving ce n ter located in the Frem ont Valley area just o u tside of Californi a Cit y in the upper Moj ave Desert. The $32 million facility opened in May 1990 a nd covers a ppro xim at ely 3800 acres, o r six square m iles. It features a n unbanked 7.5mi le o val test track wh ich con tains a wide vari ety of road surfaces a nd in some pans resembles a freewa y, a bui lding co mp lex housing offices and workshops, and ex tensi ve landsca ping. Future phases a re p lanned to add a road co urse, city driv in g cou rse, vehicle dyna mi cs area a nd an off-roa d testing area. The facility employs approximately 50 fu ll a nd pan time perso nnel, ma ny h ired from the local co m m un ity. H onda esta blis hed its relati on ship with the co m m un ity by presenting a local school wi th a new bu s a nd the Honda Proving Center sponso rs a local softba ll team for l3-l 5-year- old g irls. Honda a lso fund; a 'pro ject to study the impact of relocating Ca lifo rnia desert tonoises found o n pan of the propert y to an ad jace nt section of Bureau of 1...10(1 Manageme nt la nd. whee l slip isdetected by the eigh t-bit central processi ng unit, it a u to ma tically adj us ts ignition tim ing to cut power a nd thus elim in at e wh eelspin. Lik e the ABS, the TCS checks itsel f automatically, a nd if there is a p rob le m , sta n da rd ign iti on timi n g is maintained a nd a warn in g ligh t is illumina ted. The rid er a lso has the o p tio n of swi tchi ng th e TCS o ff, a lthough thi s must be don e when the mot or cycle is statio nary . The ent ire ABSrrCS system adds 30.9 pounds to th e ST I IO 626-po und O's cla imed dry weigh t. It a lso requ ires sl ig h tly more ma inten ance as th e wheel sensor gap must be chec ked after eit her wheel is remo ved. And th ere's a lso the added pr ice over a sta nda rd ST I IOO. Is it wo rth the ex tra COSt? Foll o wing a high -sp eed brakin g dem onstrati on by H onda 's test rid ers, we had a brief o pportun ity to find out. Us ing a port ion of Ho nda 's 7.S:mile testin g ova l, we tested the ABSrrCS systems (a nd o u r co urage) on dry pavem ent, in sand a nd through a thin layer of flowing water. . After a slow test run, we took the ST l l oo up to abo u t 60 mph on dry pavem ent a nd slammed o n the brakes. The front end dov e as it would hav e o n a ny mac hine under such cir cum sta nces, a nd wh en th e ABS activa ted, th e tires sq uealed sligh tly as th e wh eels alt ern ated between momentar ily locking a nd sp inn ing. T he wheel mo dula tio n crea ted a s lig h t vib ra tio n through the han dl eba rs, bu t it wasn 't di stracting a nd the 51' came to a smooth sto p. Sla mm in g o n the brakes o n wet pavement pr oduced th e same sm ooth stop as th e ST made o n th e dr y as ha lt. Both ends of th e ST tracked straigh t with absolutely no sl id ing. The TCS ens ured that there was no rear wh eels- pin while accelera ting o ut of the water. The TC reall y shines while accelS era ting o n grav el-strewn su rfaces. We rod e the ST down a pothol e-filled road with scatte red sand and th ere was no rear -wheel slip. Brak ing on the 'marbl es' required mor e ca ref u l rid er co nt ro l as it was eas ier for the front wheel to slig htly turn on the loose din and rocks. All of 'ou r braking and accelerati on tests were don e wi th th e bike perpe n dicular to th e gro und a nd in a stra igh t line. One rid er tested the T CS by acce le ra ti ng qui ckl y with th e ST leaned over a nd th e rear end bri efly step ped o ut. He felt that the TCS quite possibly kept the bike from sliding any furth er than it did. There a re lim itati ons to a motorcycle ABS system, a nd as Honda and o the r manufacturers suggest, a nt i-lock brakes and any form of tract io n co n tro l ar e merel y a means of providing an ex t ra margin o f sa fe ty. Uhimare control of the mo tor cycle lies with the rider's skill, judgement and riding attitude. Although the ABSrrCS system will add approxima tely $2000 to the cost of a n STIIOO - more tha n a 20% in crease, th e e x t ra sa fe ty margin provided by Ho nda's ABSrrCS g ives the rider added peace of mind on the road, a nd a controlled "escape" bra kin g system that 's wo rth every pen ny and more. Th ings bei ng what they ar e, th e size of the p urchaser's ba nk account will no doubt determ in e whether he or she Opts for the system. But perhaps someday on e won' t have to choo se. As the technology a nd popu lari ty of ABS advan ces, a n d th e ma n u fa ct u re rs recover their development costs, perhaps, as BMW has don e, they'll make a n ti-loc k br aking systems sta nda rd eq u ip me n t o n a wide ra n ge of machines. a

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