FORGOTTEN MOTOCROSS TECH: MAKING YOUR HANDLEBARS WORK LIKE FORKS
Motocross history is filled with examples of creative ideas that were heralded as ground-breaking, but, because of the rapid rate of change in development, sank into the swamp of forgotten technology. Although some ideas are best left abandoned, others were truly innovative (if not ultimately successful). MXA reveals motocross’ tech trivia. Do you remember TGT Air Chamber handlebars?
Starting in 2003 fork subtanks were the rage. What’s a subtank? Subtanks are air chambers, typically made from carbon fiber tubes and hidden behind the front number plate. These empty chambers were attached to the fork’s air-bleed holes, and at low speeds they made the forks feel like they had a greater air volume, which made the forks plusher. Then, at high speeds, an adjustable bleed system made the forks feel like they had a smaller air volume, which made the forks stiffer.
How did they do this? The braided line leading from the top of the fork cap to the empty chambers had a bleed valve on it. At low forks speeds, the air could easily move through the open valve, which convinced the fork that the air volume was greater (which translated into the forks thinking the oil height was lower). Conversely, when the fork speeds were higher, the air couldn’t move through the bleed valve fast enough, which resulted in the forks having lower air volume and a feel similar to having a higher oil height. The original subtank idea came from Enzo Racing, but the ultimate expression of it was embodied in the $254.40 TGT Air Chamber handlebars, which used the hollow portion of the oversized bars as the subtank.
There were 27 clicks of adjustment on the dial. With the dial turned all the way in, the air chambers were shut off completely and the forks felt exactly like stock. MXA ran the clicker at 14 clicks out to get the best overall feel. In 2009 TGT private labeled the air chamber bars to Moose Racing. Sadly, subtanks, like most suspension innovations, disappeared as technology moved on.