Review: Fox’s Supple Factory FLOAT CTD Boost Valve Rear Shock
After a couple of warranty visits for our 2012 BMC Trailfox test bike’s stock shock, we and Fox came to the realization that the unit on that ex-demo bike was just bad egg that needed replacing. After talking with the pros at Fox and BMC, we decided to bring the bike up to date with an upgraded Factory series Float CTD model. Even though clearance issues on the ’12 linkage forced the change to a small-can model, we weren’t expecting big performance improvements from the updated shock. We were wrong. Hit the jump to find out more…
For 2013, Fox introduced their Climb-Trail-Descend damping scheme. Providing largely locked, active-but-firm, and fully open settings, Fox have aligned the distinct compression damping settings with their intended uses. From the first ride, it was clear that Fox’s latest damper compliments BMC’s Advanced Pivot System well. To our shorts, it feels as though Fox have managed to do a better job than ever before at separating low- and high-speed compression damping. This means that any of the three Trail settings can be engaged to control bobbing and limit dive and overtravel without sacrificing high-speed or small-bump compliance.
Further aiding in small-bump activity is Fox’s exclusive use of Kashima Coat. At the “Factory” level, Float rear shocks get the slick (and sexy) gold coating inside and out. While bog standard hard anodizing is very durable, creating a ceramic layer on top of the base aluminum, that layer is porous and can actually be rough pretty rough. In the case of some cookware a hard anodized surface is actually impregnated with Teflon for a combination of durability and easy cleaning. Taking this concept one step further, Kashima developers Miyaki impregnate the Fox shock’s hard anodized surfaces with lubricating molybdenum disulfide for tough and slick shock surfaces- in this case improving wear while reducing stiction.
Even though it was driven by clearance issues with the ’12 Trailfox linkage, the change for this 140lb rider to a small-can shock was an easy sell. When considering shock replacement, other small riders should consider the same: a smaller air chamber at little guys’ and gals’ air pressures makes for a spring curve that is somewhat more progressive than it would be at the same pressures in a larger shock. This allows for good performance early in the stroke without resulting in excessive bottoming. As you can see from the photos, every bit of the Trailfox’s 150mm travel is used regularly: the CTD damper and somewhat steeper spring curve just ensure that it’s used when–and only when–it’s needed.
The net result of the change from a ’12 Fox RP23 is a bike that sits a bit higher in its travel when pedaling, better maintains traction while climbing, and is even smoother on descents than the ProPedal shock it replaced. Big hits are every bit as controlled as before and, as much fun as the descend setting is, the first Trail setting is good enough that the shock stays in a single setting more than ever before. While the $440 price tag keeps the upgrade from being a no-brainer, it doesn’t seem unfair for a complex product that is made right here in the USA (with parts Kashima Coat-ed in Japan). Forgoing the slick coating and replacing three Trail setting with one will save nearly a third- making the US-built Evolution Float CTD look like a steal at $310.
If faced with an older or ailing shock, the upgrade to a CTD Float will be noticeable a step forward. In this case, it has taken everything good about the BMC Trailfox and turned it up a notch. And that’s an upgrade that’s hard to argue with.