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/126045
THE PEOPLE At S&W: Tim With am origi na lIy in te rested hi mself in co mp ression an d rebound of me chanical th in gs through high building valve spri ngs for pe rforman ce fo ur-st ro ke twins. His product is sti ll a near -requiremen t in the 75 0s t hat to ur th e Grand National circ uit. From th at ca m e fork springs and shock springs an d, af ter he became o ne of th e first if n ot th e first Ame ric an independent to st ar t usin g a shock dy no , cam e S&W shoc ks. He is now allied with C.H. Wheat, a very fast m an for near ty two decad es firs t o n four-strokes and then , Maicos. With these tw o , as with th e o the r " dividu als in considered, you get the feeling that they really kn ow what th ey're doing with their boingers, T hey don 't just react to fads and fancies; these American sh oc k designers start the susp ension fads. At Fox Shox : Steve Sim on did just that wh en he g<1~ ' th e idea of putting larger ca pacity re~rvoirs and coolers o n KONI sh ocks. Then came air forks and, air/gas shocks designed to keep o n working when even KONI Kooters They were produced and faded. marketed by the Motocross Fox. That's Dr. Geoffrey T . Fox , who used his ph ysi cs background to co me up with the actual design of th e Fox Sh ox. He gives Steve credit for h elp o n th at even as he j ustifia b ly takes some credit for inp uts on the air fo rk de sign. Geoff's Ph. O. is from the Univer sity of Wiscon sin ; his co mpe tit io n knowledge was extracurricular, now it's a full-time app lication . At Cumutt: How to dea l with a personali ty as restrained and co rrec t as Curnutt? He knows his Chuc k limitatio ns as a busin essm an and he also knows his radically different successful approaches as a practi cin g en gin eer. He re tains a gra yin g cre w-cu t an d an evergreen conviction th at his way works best. With gen uin e understanding for the m an and th e product that bear his 28 name, you can see where he' s co ming fr om. He does su spensio n so simply and, for th e most p art, he makes it wo r k. He is not lacking in hu m or an d will sometimes ackno wledge with a grin th at w he n it co mes to his shocks " People ei t he r sw ear by them or swea r at t hem ." At Boge /Mulholl and: Oscar Franck refle cts th e fin est qu alities in th e of Mexican- bo rn gro wing class te chno-aristocrats. He is resp onsible fo r hrining the Boge /Mulh olland damper in to th e Interpar t marketing gro up . A stro ng engin eering educatio n helped in the o riginal design, but he transitions with th e sm oo thness of class through roles as engineer, market er, and division head. In th e U.S., he would pro bably en d up at Chase Manh attan Bank - as he prob abl y could in Mexico - but that doesn 't interest him, High performan ce ra cing products do. Gil At Works Performan ce : Vaill an court wa s, not to o m an y yea rs back, livin g and working out o f his trailer with nothing but an idea on building motorcycle suspension and trying to make a living at it. As a graduate of th e Montreal Conservat ory of Musi c and a co nc er t violinist, he came to the U.S. so m e 15 year s ago to st ud y physi cs (which, surp risingly, has direct musical rel ationship ) but the language barrier was too much an d he had to drop out. Gil has sinc e learned acc en t-free English and still enjoy s musi c but his most productive harmonics are n ow in spring-fluid d amping. . One of t he test riders p oin ted o u t th e one thing he liked best ab out the shocks being evaluated : "If yo u've got a problem , you can go talk to th e gu y and get it sorted o ut, Hav e yo u r shock built any way you need it." In a tim e of inc reas ing dep ersonalization on every level , th ere is so meth ing to be said fo r th at. THE HARDWARE Th e most difficult thing to ge t a handle o n in this whole en terp rise was the thinking behind the springin g on these varied dampers. The springs offere d ranged from 70 lb /in to 83/19 5 sp lit springs to 94 /1 3 8 pr ogre ssive wind coils. Even mo re perplexing was the fact th at , with in a fairly narr ow ran ge o f riding to lerance , all of them w or ked pretty well. How can th at many diffe re n t ap proache s p roduce substantially the same effe ct? In no particular o rde r, her e are the physic al descr iption s of the five types of damper we took a ri de on . S&W dampers retain th e twin tu be with the sign ific an t cons truc t io n difference tha t the entire volume o f the inn er shock is filled with damping flu id. of flu id by th e Displacement co mp res sed ro d is accounted for by a sm all plastic bag fille d with inert freon gas. As an an ti-aerea tio n de vice , it is stone simp le . The only possi ble element th at could fail is the bag, whi ch could split, excep t th at none have sinc e the freon is under suc h low pressure th at even when the ba g is sq uished nearly flat, th ere isn't th at much stress on th e sealed seams. Th e S&W uses three poppet valves in the damping piston which are little more than sm all spring loaded balls resting in orifices wh ich create different fluid . flow rates . This same general principle, with va ria t io n s as to psi required to overco m e the valve resistance and how much damping is done on co mp ressio n co mp ared to damping on rebound, is used in the Works Performan ce shocks (which, in chro nological o rd er, seem to have the id e a ) an d o rig i na te d Th e piston is Boge /Mulh olland. O-rin ged, of co u rse , but because of th e understressed desi gn of th e damper, even if there is so me wear it isn' t cri tical. There are five adjustable pre-load position s for the springs which ran ge from 60 lb /in to 9 0 lb /in de pendi ng on rider wei ght, speed, and track co nditio ns . Ou r te st shock s had 70 an d 75 lb /in springs. S&W sh ocks with springs weigh 4.2 lbs. ea ch and cost $8 6.5 0 a pair. They are not adjustable exc ep t for spring pre-load and are not intended to be rebuildable by th e o wner. C.H. explain ed that it didn't m att er wh ich en d of th e sh ock was up. At Boge/Mulholland th ey beli eve in co mp ression damping, as an effo rt to force th e ro d in quic kly wiII reveal if y ou don't believe th e brochure . They retain double tu be co nstruct io n usin g a ~as bladder inflated to low pressure (similar to th e S&W approach) to prevent aere at io n . The tube s are co mp le tely filIed wi th over 130cc of specialIy formulated MuIh olI an d shock flui d. All of th e shoc ks te sted had capacities o f 120cc or better. Something around 75cc of fluid used to be co ns ide red the norm. Mulholland shocks h ave the three-st age relief valves for d amping both co mp ressio n an d reb ound st ro ke. They use a double lip seal on the dampirig pi ston and stress the fact th at Boge/Mulh olland sh ocks are designed to be custo m- tuned by the o wn er-r ider. They offer a very co mple te range of p arts that a ffect damping behavior (in ad di t io n to springs) and are intended to be rebuildable, or infinitely alterable. Two different springs were o ffered : I 12 lb/in straight wind and 94 /138 progressive. With the 94 /138 springs in place , th ey weigh 4 .8 5 lbs , The cost of the dampers alone is $89 .95. Straight wind springs are $22.50 and progressive wind sp rin gs are $27 _50 addit ional. Total minimum for a fun ctional set : $11 2.45 . The Works Performance dampers were the only American shoc ks tested th at were all-hy drulic. * They do not feature any pressurizati on or fluid displacement co mpen sa ting device. Gil " ask ed th at th ey be m ounted with the '8 sh oc k body up. There is progressive ud three-st age valvin g to co n tro l damping, _ cooling fins a t th e end o f the shock bodies, and 110 lb /in str aight wind sp rings to co mpress on th e bumps. They are of twin-tu be co nstruc tio n with the , rl oute r tu be die cas t alu m in um an d th e US inner one, steel. Springs and shock - d bodies are KaI-Gard coated to prevent I i, co rr osio n. Works Performance shocks ""