Trek's Andrew Shandro was spotted rolling through the Crankworx festivities today with a rather sharp looking Slash, but there was something far more interesting about his bike than the glossy root beer-esque colors courtesy of Trek's Project One shop. The bike's fork, which appears to be a standard Fox 36 Factory Float, is actually home to a brand new damper that is most definitely not a FIT4 system, despite the misleading decals on the lowers.
So, what is the damper? My guess is that it's an evolved version of Fox's much-lauded FIT GRIP damper that's much more adjustable compared to the price conscious version used in Fox's other GRIP forks.
What's the difference between a FIT4 system and a FIT GRIP system? The FIT4 damper is closed and all of the damping oil is sealed inside of the cartridge, it's bled free of air, and it also uses an extruded rubber bladder as a compensator for oil displacement as the fork is compressed. The FIT GRIP damper is also closed, but it employs a spring-backed internal floating piston (IFP) as a compensator - it does the same job as the bladder in the FIT4 damper - but, according to Fox, has completely different anatomy. ''They are both FIT (Fox Isolated Technology) sealed cartridges, but use different design architectures,'' Mark Jordan, Fox's Global Marketing Manager, explained to me in my review of Fox's 34 Float GRIP fork
''Simplifying things a bit, the FIT4 design uses different flow paths to achieve different compression damping settings, while the GRIP damper increases / decreases force on the shim stack to regulate the compression damping.'' Rather than being a budget version of the FIT4 damper that's manufactured with more cost effective components, the FIT GRIP damper is so different that it doesn't actually share a single part with the FIT4 design.
The 34 Float GRIP fork that I reviewed last October impressed me with its performance, but the damper in Shandro's fork is likely a different animal - the big news is that it has separate low-speed and high-speed compression dials at the crown, and also separate low-speed and high-speed rebound dials at the bottom of the leg, making it a four-way adjustable fork to match their X2 shocks. I wouldn't be surprised to learn that this damper has been used, or will be used, in other longer travel forks as well.