In the last two years, FOX stumbled a bit in fork technology since the inception of CTD forks. Considered the leader in bike suspension for the last decade, riders observed that the recent crop of forks lacked suppleness and control. But as competition heated up from the likes of RockShox, FOX invested heavily in R&D to get back to their performance heritage. We saw what they were capable of with the performance of their FOX 36 forks last year which were received with near unanimous acclaim. Now most of that technology comes to the more popular 34 line of forks.
What did they improve? In a nutshell, everything. They left no stone left unturned in their quest back to the leadership position in bike suspension.
- New self-equalizing positive/negative air spring
- Utilizes our patented Float shock transfer port technology, first introduced in our circa 1999 Float shock
- Smoother performance with reduced friction
- Less vibration feedback through handlebar
- 219 grams lighter in 27.5 and 297 grams lighter in 29er
- Highly tunable with air volume spacers
- Adjust the amount of mid stroke and bottom out resistance
The fork chassis is all new with every piece losing a few grams to contribute to the weight loss challenge. The big weight loss though comes from the new FLOAT air spring in the fork which controls compression and rebound. Compared the Fox 36 air spring, an inner rod was lost in favor a cleaner, lighter design that incorporates indentations in the inner stanchions to let air pass at the prescribed location. The 27.5 fork loses 219 grams compared to the 2015 model. The weight of the new 160mm fork is now 1746 grams which is lighter than the RockShox Pike as well. The 140mm 29er version loses a whopping 297 grams (.65 lbs) over the 2015 model. Chassis stiffness numbers are all maintained despite the weight loss.
Small bump compliance
The new FIT4 damper utilizes a new, equalizing positive and negative air spring. This brings the fork in a state of equilibrium at all pressure levels and it becomes easier to initiate bump compression. Flow paths have been improved too with a larger 10mm shaft so more oil can flow through the base valve. It’s the same architecture as what’s found in the FOX 36 and 40 with less friction so this fork is much smoother over small bumps and trail vibrations.
With the new negative air spring, the negative coil spring has been removed as well. This not only improves weight but also the noise and vibration level as the spring is no longer buzzing inside the fork. And since the negative air spring is self adjusting when charging the main chamber air pressure, lighter and heavier riders are all served equally with the optimum negative pressure and small bump compliance.