Ben Posted October 16, 2014 Report Share Posted October 16, 2014 [h=1]Air Suspension Rides Again! “There’s gotta be a better way…”[/h] October 15, 2014 By Kevin Cameron 1 Comment Motorcycle suspension innovation arises where it is most urgently needed, off-road, where, for example, motocrossers must survive hundreds of what are effectively Navy carrier landings reliably and in good control. Long travel, gas shocks, upside-down forks, and progressive-link single-shock suspensions all came to road-going motorcycles from motocross. The idea of using the compressibility of air as a spring is old. In 1910, ASL in Britain built an all-air-sprung bike, and in the late 1930s, Velocette, with George Dowty, applied the then-new concept of aircraft landing gear oleo-pneumatic struts to motorcycle rear suspension. Today we often drive or ride behind trucks that proclaim “air ride,” and we can see black fiber-reinforced rubber air springs supporting the load. The big problem with air suspension, however, is that it stiffens too rapidly during compression to provide an off-road motorcycle with the long, supple travel that’s needed to smoothly track fast-undulating terrain. In 1976, only two years into the Era of Long Suspension Travel, air forks were suddenly hot, and to make them stiffen less rapidly, large pressure reservoirs were screwed to the fork caps. That time, air came and went. Since then, every time a mechanic or engineer hefts the several pounds of steel springs required to support a motorcycle, that person has surely thought, “There’s gotta be a better way.” Now air suspension is back, with a fresh concept to counter the rapid stiffening of air springs. What’s new is the idea of adding an anti-spring (one that tends to compress the fork) to buck out much of the stiffening. Showa call its design “SFF/TAC,” which decodes to Separate Function Fork/Triple Air Chamber. Separate function is not new; other makers are also using the idea of putting all damping in one fork leg and all springing in the other. The Triple Air Chamber idea uses air pressure in three separate chambers to give long, relatively linear travel, with steep progression beginning only as full compression is neared. The bottom line here is to eliminate the considerable mass of steel springs that teleforks have carried since the beginning. Just as pneumatic springs eliminated the excess weight of steel springs in high performance valve trains (as used in Formula 1 and MotoGP), enabling such lighter valve trains to accurately track abrupt cam profiles at high rpm, so air forks, by eliminating several pounds of steel springs, now enable front wheels to rebound faster to track the terrain. With the wheel on the ground more of the time, grip is improved. Kayaba’s PSF fork (Pneumatic Spring Fork) also uses an anti-spring, but it is metal. The concept is the same: to buck out the air spring’s tendency to stiffen too rapidly, leaving a large linear region of front wheel movement to better follow the landscape. At present, these forks suffer from adjustment complexity and the need to reset pressure frequently. With the value of the concept proven, many people will tackle the problem of how to smooth out the details, better contain the air, and make the basic concept more easily usable. http://www.cycleworld.com/2014/10/15/future-of-air-suspension-technology-in-motorcycle-forks/?src=SOC&dom=tw Quote Link to comment Share on other sites More sharing options...
Throttle_Jockey Posted October 16, 2014 Report Share Posted October 16, 2014 Interessanter Artikel! Wenn ich aber überlege, wie oft es doch bei der Gabel mal kurz aus dem Simmerring schmoddert und das bei den neuen Gabeln dies direkt im Luftverlust gipfelt - ne, will ich nicht haben. Bei den MX Leuten fluchen auch mehr als genug Fahrer, dass sie nach einer kleinen Runde direkt einen lowride Crosser haben. Weiss denn wer, ob Öhlins und co auch mit dem Lufttrend gehen? Quote Link to comment Share on other sites More sharing options...
Guest Connader Posted October 16, 2014 Report Share Posted October 16, 2014 At present, these forks suffer from adjustment complexity and the need to reset pressure frequently. With the value of the concept proven, many people will tackle the problem of how to smooth out the details, better contain the air, and make the basic concept more easily usable. Wird sicher noch kommen^^ Quote Link to comment Share on other sites More sharing options...
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