FOX’s new CTD-equipped forks feature a simplified interface to help even novice buyers eke out the most performance (James Huang/BikeRadar)

FOX – formerly known as Fox Racing Shox – have debuted yet another giant round of new products for the 2013 model
year: an expanded 34 fork range, a much lighter 29er cross-country fork,
and their long awaited
DOSS seatpost, which we’ve covered in depth already. 

But the biggest change is the new CTD damper, which
refines FOX’s already excellent hydraulic design into a simpler interface
that’s intended to help any rider more readily extract the best performance
from their suspension without requiring a degree in fluid dynamics.

What is CTD?

CTD is a new compression damper design that’s integrated into all FOX
32 and 34 forks as well as all Float rear shocks. The thinking behind the new damper can be inferred by what the acronym stands for: Climb,
Trail and Descend. 

Instead of having individual controls and lots of clicks for
low-speed compression, lockout, ProPedal and blowoff threshold, CTD instead
reduces the options to just those three settings with all of the adjustments
pre-selected for each of those riding situations.

‘Climb’ mode offers the firmest feel and most efficient ride, closing
off all of the damper circuits save for a single blowoff piston with a high
threshold. Cross-country oriented forks and shocks will be preset with an
extra-high threshold while trail oriented units will have a somewhat more
forgiving tune.

‘Trail’ mode retains the blowoff piston but adds a second port with a
needle valve to provide some low-speed compression tuning – higher-end models
get a three-position ‘Trail Adjust’ needle to fine-tune the feel.
Yet another port feeds the oil into a separate preloaded shim stack for
mid-high speed control. Current FOX suspension users will find this
mode analogous to existing ProPedal settings, offering a slightly firmer feel
overall but still with enough bump control for most off-road riding situations.

Finally, ‘Descend’ mode shuts off the blowoff piston and needle valve
ports in favor of an open port and the same preloaded shim stack for the
greatest possible oil flow, thus offering the best square bump
performance and the softest feel for maximizing the travel use in faster
downhill situations.

Purists will invariably scoff at the new CTD design, saying it removes
a level of customization and fine-tuning available with the current models’
collection of individual adjustments. While there may be some truth to that
(we’ll get to our ride impressions later), CTD’s simplified interface takes the
guesswork out of the process and will make it easier for the majority of FOX
suspension users to extract more performance.

In addition, FOX will offer optional cable-actuated, three-position
remote levers that can control either the fork or rear shock – or both at once
like Scott’s TwinLoc system. Forks can be easily converted between
crown-mounted knobs or handlebar remote levers by swapping just a few small
parts instead of trading out an entire damper assembly as on previous versions. 

While adding the remote removes the external Trail Adjust feature, the desired tune can be preselected internally when swapping out the bits. Rear shocks are unfortunately remote or manual-specific but the remote-equipped models get a vastly tidier and lower-friction setup than before with reversible routing.

A small window indicates the selected mode on the dual CTD remote lever. Three mounting holes allow for some fore-aft adjustability

Expanded 34 range and new
650B options

FOX’s collection of enduro-themed, 140mm-travel 34mm chassis forks
proved popular last year, offering a 20 percent claimed stiffness boost over an
equivalent 32mm fork but shedding 200g (0.44lb) from a comparable 36 and
offering the same strength. FOX expand from two models last year to
six for 2013, adding not only a 26in-wheeled Float and travel-adjustable
TALAS but two 650B versions as well – both with a generous 160mm of maximum

The new 34 forks – and in fact, all air-sprung FOX forks with 130-180mm
of travel – also get a revised air spring. According to FOX, rider and bike manufacturer feedback suggested the previous spring rate was too progressive so the negative
spring is now longer and uses a softer spring rate, thus flattening out the
curve deeper into the travel for a more coil-like feel while even reducing the
initial breakaway force for improved sensitivity.

All 34 forks are air sprung, with 15mm through-axle dropouts and tapered steerers. Claimed weights for the top-end Factory-level forks are as follows:

  • 34 Float 26 160 FIT CTD: 1,950g (4.30lb)
  • 34 TALAS 26 160 FIT CTD: 2,040g (4.49lb)
  • 34 Float 650B 160 FIT CTD: 1,990g (4.38lb)
  • 34 TALAS 650B 160 FIT CTD: 2,070g (4.57lb)
  • 34 Float 29 140 FIT CTD: 2,040g (4.49lb)
  • 34 TALAS 29 140 FIT CTD: 2,120g (4.68lb)

FOX expand their range of 34mm-diameter forks to both 26in and 650B wheel sizes for 2013. This is the 34 Float 26 160 FIT CTD

Lighter 32 chassis for 2013

FOX engineers have attacked the 32 range with a healthy dose of FEA (finite element analysis), lopping
125g (0.28lb) from the lightest 26in 2012 model and a whopping 204g
(0.45lb) from the lightest 29er model, meaning the 2013 model year will mark
the first time FOX have broken the 3lb barrier. Common changes include a more
aggressive 80mm transition on tapered steerer tubes (-23g) that will allow
for shorter head tubes, refined crown forgings (-36g to -42g depending on
model) and new magnesium lower leg castings (-63g to -109g)
with more finely tuned butting profiles, a more intricately webbed arch and
more carefully ribbed dropouts.

The company will offer a total of 19 different 32 forks for the aftermarket, with travel ranging from 100-150mm and applications covering pure
cross-country, trail, all-mountain and even dirt jumping. Options for most
models include 9mm open or 15mm through-axle dropouts, straight or tapered
steerers, and sealed FIT or open bath cartridge styles.

Weights for key Factory-level models are as follows:

  • 32 Float 26 100 FIT CTD: 1,350g (2.98lb)
  • 32 Float 26 150 FIT CTD: 1,746g (3.85lb)
  • 32 TALAS 26 140 FIT CTD: 1,660g (3.66lb)
  • 32 Float 29 100 FIT CTD: 1,470g (3.24lb)
  • 32 TALAS 29 120 FIT CTD: 1,840g (4.05lb)

FOX have trimmed the weight of the 32 Float 29 100 FIT CTD fork down to just 1,470g

Tweaked Float rear shocks

All Float rear shocks will feature CTD dampers for 2013 and while the
exact mechanism by which the three oil paths are run and selected differ from
the forks, the concept is the same: more attainable performance levels from a simplified
three-position interface with top models also getting three sub-settings in
Trail mode. In the case of the Float rear shock, the blowoff piston used in the
fork’s Climb and Trail modes is replaced by FOX’s awesome Boost Valve
technology, with a wide range of factory air pressures to provide the desired

Keen-eyed readers will notice the new head and air sleeve design,
which shaves about 33g from the previous version while also offering more air
volume for a flatter spring curve and more surface area for improved cooling. Optional clip-in spacers will recreate last year’s more progressive rate if
desired and there are also two additional air sleeves with progressively larger
volumes and even flatter spring rates where appropriate. 

Other small improvements include much more positive and stronger
detents for the machined aluminum adjusters, and hugely improved seven-piece
mounting hardware with resin flange bushings and an aluminum through-pin that
greatly reduces friction plus O-rings to seal out moisture.

The simplified controls on the new Float rear shock consist of a three-position CTD selector, a three-position Trail Adjust dial and a rebound knob

FOX expanding from hardware
into software

As it turns out, last year’s Smart Pump teaser was just a precursor for
FOX’s new Intelligent Ride Dynamics advanced development program. That project
is still pending but coming later this year is a trick shock pump with a
precise digital gauge for more accurate fork and shock inflation. Coming even
sooner than that – in just a few weeks, in fact – is a fantastically clever
setup app for use on iOS and Android platforms.

The new app guides users in the setup process in easy to follow,
step-by-step prompts. All 2013 forks and shocks will feature a unique
identifier code, which is entered into the app to provide factory tuning
information such as model type, Boost Valve pressure, air can volume, shim
stack characteristics and other metrics. The app uses that information along
with the rider’s weight to suggest an initial starting pressure.

The rider then sits on the bike and records the sag position as usual
via the O-ring that’s installed on every fork and shock. The next screen is the
really neat part: you then move your iOS or Android device so that the image of
the stanchion overlays the template on your screen. If your O-ring falls within
the green shaded band, you’re good to go. If it falls outside of that window,
just note whatever number is sitting next to the current position, inflate the
fork to that value and repeat the process until you’ve got it right.

Once the sag is set, the system will even suggest a rebound setting based on the known damper characteristics and then record everything in a digital file you can refer to later as needed. In keeping with the theme of CTD, the new app is easy as pie to use and should help users at least achieve proper baseline values for good performance.

Ride impressions

We spent two days just outside San Jose, California sampling many of
FOX’s new 2013 wares and while we won’t have a thorough assessment until a
longer-term trial on familiar ground, we certainly have enough to generate
some initial thoughts (we covered the DOSS seatpost already so we
won’t repeat ourselves here).

CTD indeed requires more experienced users to ‘let go’ a little, given
that the previous assortment of dials and knobs has now essentially been
replaced by a three-position switch that does the thinking for you. As expected, Climb mode is ideal for long fireroad climbs, with almost
no movement when pedaling in the saddle but enough give to take the sting off
if you hit something. 

Trail mode was perhaps our favorite overall, offering up
a surprisingly supple or subtly firm feel depending on which of the three Trail
Adjust settings you’ve selected. There’s almost no harshness to speak of and
yet there’s plenty of platform and springiness to push off of if you’re trying
to preload the suspension and shoot yourself out of corners and over obstacles. Depending on the quality of the rear suspension design (we rode both a
Yeti SB-66 and a Santa Cruz Tallboy C), it even works well enough that we
almost never felt the need for the Climb setting.

We tested FOX’s new 32 Float 29 100 FIT CTD Remote on Santa Cruz’s Tallboy C

We weren’t quite as keen on the Descend mode, though, especially when
paired with the flatter spring rate of the new 34 Float 26 160 FIT CTD. It’s
certainly ultra-supple and erases many typical-sized hits but we found ourselves blowing through the travel coming off of even modest-sized
downhill steps. There was also a lot of brake dive before entering into tight
switchbacks. We generally preferred the softest Trail setting instead but we’d be curious what the new fork would feel like with a bit of extra oil in
the air chamber – thus increasing the spring rate progression.

Just like on the DOSS seatpost, our impressions of the new CTD remote
system were decidedly mixed. On the one hand, the system works.
Changes in settings are very noticeable, switching both fork and rear shock
simultaneously yields a balanced feel in most situations, and the lever action
is impressively light. However, the two-stage lever design is awkward to
operate and the ergonomics leave much to be desired.

More critically, adding the dual CTD remote in conjunction with a
dropper seatpost results in a confusing array of controls on your bar – eight
separate levers in all if you’re using a DOSS! It was certainly confusing at
first, though we started to get the hang of it after about an hour.
Even so, it’s a lot of clutter and a lot to think about, particularly if you’re
trying to make all those adjustments on a demanding section of trail.

When both the DOSS dropper seatpost and dual CTD remote are mounted in conjunction with front and rear shifters, the result is a veritable rat’s nest of cables

We’re still awaiting final pricing but in typical fashion, all of this
gear will begin arriving in stores in just a few weeks. We’re expecting our
test samples in that timeframe, too, so check back for a more thorough
assessment here on BikeRadar later this summer.

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