Review: Fox Live Valve Suspension

"Just ride your bike." That's what Fox's Live Valve is all about. The premise is simple: Live Valve turns on your bike's suspension when you need it, and turns it off when you don't. Most trail bikes allow you to perform those functions manually, but the reality is that you are not smart enough to know exactly when to switch those levers, and even if you were, you would not be quick enough to switch them in time for your decisions to be effective. Live Valve gets it right every time. You push a button and ride your bike. Your suspension works. Pedaling feels seamless.

Suspension levers, anti-squat, platform damping, and inertia valves are all coping mechanisms. We optimize suspension kinematics between good pedaling and a good ride. We anticipate the trail ahead, make a best guess - maybe we'll turn something on or off - and then we live with the results until circumstances change dramatically enough to warrant a different decision.

studies for auto accidents reveal much slower reaction times: 1.7 to 2.3 seconds before the brain can get the body to respond. Those figures may apply if you are riding a Scott or a Cannondale with a dual-remote suspension control, but if you plan on taking a hand off the grips and fumbling for a lever... taste eternity, my friend. By comparison, Fox Live Valve can sense an impact and respond in .003 seconds.



How Live Valve Works

Fox Live Valve's heart is a magnetic valve a little larger than a pencil eraser that opens and closes the same low-speed compression circuit that is used for Fox's manually-controlled forks and shocks. This "latching solenoid" valve is packaged to fit inside both suspension components. The fork module simply replaces the damper-side top cap, while the shock module fits inside a second "piggyback" canister that sits parallel with the shock's IFP reservoir.

Two accelerometers, one in the fork arch, and another near the rear axle, sense and measure the velocity of vertical movement to register impacts. That information is sent through wires to Live Valve's microprocessor.



The brain of Live Valve is a small frame-mounted microprocessor (Fox calls it their Controller) that also houses a removable 7.4-volt battery. Key to the Controller is its cluster of sensors that indicate whether the bike is level, pointed up or down, or free falling. When an impact is sensed, the controller uses those four functions to determine whether it will open the fork, open the shock, or open both components. The interval between sensing an impact to opening the dampers is only three milliseconds - that's one hundred times faster than the blink of an eye. Opening the suspension's low-speed damping circuit in the nick of time, however, is only half of Live Valve's magic.



Live Valve's default is closed - the equivalent of you running your shock and fork in the firm pedaling mode. The Controller only opens the suspension after an impact, and it has a pre-set timer that tells it when to switch the servo module back to firm. The magic is that the controller consults its "tilt" and zero-gravity "Free Fall" sensors and alters its timing sequences accordingly:


Descending: When the Controller senses the bike is angled downhill more than six degrees (the grade-angle can be programmed), impacts from either wheel will simultaneously open both the shock and fork, while the time interval to return to firm mode is further extended to ensure that the suspension feels unimpeded. It will return to firm mode if the terrain is smooth, so you can win downhill road sprints on the way home.

Free fall: Free-fall is sensed only by the Controller, which opens the fork and shock until the frame and fork-mounted accelerometers register that you have returned to earth and the bike is rolling smoothly again.

The takeaway here is that Fox developed an algorithm that senses what you are doing on the trail and tailors the suspension to enhance that experience. The addition of the tilt and free fall function also assures that Live Valve won't get confused while you are smashing through crazy zones.



Adjustments

Don't worry about losing your conventional adjustments and clickers. Because Live Valve only affects the adjustable low-speed compression damping circuits, all other functions of the fork or shock are the same, including the damping piston's valve stacks, external rebound dials, and air cans. Manual low-speed compression adjustments are made via a flush Allen-hex screw in the face of the Live Valve modules. It's not as pretty as an anodized dial, but it gets the job done.


Live Valve always remains open for air-time and in rowdy terrain, Fox's downhill settings will remain open full time. That is when most of us want our suspension to work full time anyway. Switching to a higher threshold setting creates a firmer pedaling feel, especially while pushing big gears, where some riders want the timer to close down earlier at the expense of a proportionately harsher feel over chatter and roots. In most settings, however, only the small-bump sensitivity changes. Medium and large hits feel much the same.



Can I Program Live Valve at Home?

Fox says that at present only OEM bike makers and Fox service centers can re-program Live Valve's timing algorithms using a PC up-link. This is necessary to customize the system to match various suspension kinematics, and applications. There is the possibility that users could be given this power in the future, but as of now, Fox is taking a conservative approach as it releases the concept into the wild - at least for the first year.

Fox is still working out the details, but their plan is to give key retailers and service centers the technology to custom tune Live Valve suspension and later, offer a variety of plug-and-play pre-programmed tuning maps directly to consumers. Fox furnished me with a PC loaded with Live Valve software and walked me through the programming process. It was intuitive to use and the effects on the bike's performance were tangible.


Do Live Valve Shocks and Forks Need Special Tunes?

Fox encourages riders to set their suspension exactly how they like it. There is no need to change your air pressure, sag, or rebound damping to adapt to Live Valve. That said, the full-time pedaling action affords riders the option to choose a more gravity oriented tune without paying a penalty elsewhere on the mountain.



Is Live Valve Compatible With Other Systems?

Fox investigated a number of options, including compatibility with Shimano Di2, and wireless actuation (like Bluetooth), but none of them had fast enough response times. In the end, Fox had to develop their own electronics from scratch. The decision to develop Live Valve from the ground up paid dividends in many areas of its development. Live Valve's latching solenoid valve, for instance, uses permanent magnets to retain the needle valve in position. To open or close the damping circuit, an impulse signal momentarily disarms the magnet - after which, the valve requires no additional current to remain in position. Similarly, Fox's electronic team were free to develop algorithms specific to Live Valve. As a result, the system is deceptively simple and draws little from its battery.



What about battery life?

Fox estimates Live Valve's run time on a fully charged battery at 16 to 20 hours. The two-cell 7.4-volt Lithium Ion battery is essentially the same as the one Shimano uses for its Di2 shifting, although the two systems are not interchangeable. Recharge is via a USB cable and this can be done while the battery is on or off the bike. The battery has a quick-disconnect feature and is sealed (like the entire Live Valve system) against the elements to IPX7 standards.. Charge times are in the neighborhood of 1.5 hours, but if you forget, a 15-minute charge will get you through a two-hour ride.

Low battery default: If the battery fails or runs down, Live Valve defaults to open mode. Your descending will be optimized and at worst, you'll have to pedal home with your suspension in soft mode. That shouldn't be a deal breaker.



Which Forks and Shocks Will be Compatible?

So far, all Fox forks with FIT 4 dampers are compatible with Live Valve (32 Step Cast, 34 and 36 forks). Float shocks with the dual piggyback design will be available with EVOL air sleeve in standard, metric and trunnion configurations. Fox designed the dual-chamber reservoir to flip-flop forward and back on the shock body in order to fit up with frames that have clearance issues, or to make room for water bottles.






Significantly less for OEM customers: Pivot's Chris Cocalis says that the up-charge on their Mach 5.5 (which features the Fox Live Valve 36 fork) will be $2000 - still a chunk of change, but if it will make you feel better, that's equivalent to the cost of an elite-level carbon wheelset. Giant and Scott will also be offering OEM-spec Live Valve models and currently, Rocky Mountain and Niner have joined a growing list of brands that have Live Valve friendly bikes in production.

Understandably, bike makers initially will be offering Live Valve on their upper-echelon models. Giant will lead with their Shimano XTR 9100 equipped 2019 Anthem Advanced Pro 29-0 at $11,500. Scott will feature Live Valve on its top-level Genius at $9,999 USD. Fox projects aftermarket sales will begin this fall.

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millimeter-stroke Fox 36 fork up front. I had doubts that Live Valve could manage a significant improvement in the Mach 5.5's pedaling efficiency, as it already rates at the top of the list (sans damping aids). Live Valve, however, would prove me wrong.


Initial Setup

Charging Live Valve can be done on or off the bike. Just pop open a waterproof cap and plug in the micro USB cable. Two hours later, you're good to go for a week or more of riding. Two clips retain the battery module, which is sealed from the elements by an O-ring and Fox provides a doppelganger cover that replaces the module to protect the internals while the battery is gone. Much like Shimano Di2 shifting, Live Valve's battery lasts so long that you'll probably forget to charge it at least once.



Mechanically, I was prompted to set my suspension exactly to my previous preferences, If you're interested, that's 20% sag up front and 30% sag out back, with a few clicks of low-speed compression damping and with my low-speed rebound straddling the midpoint - a little too fast to tame G-outs at a slow trail pace and just fast enough to take the edge off of baby head rock gardens and roots on the downs. How many clicks that is would depend upon whether I am riding in North Carolina or Southern California.

Push the on-button, choose your threshold setting, and then Live valve takes care of the rest. I chose the number two option, which remains my favorite to this day. Initially, there are few sensations that signal Live Valve is at work. The latching valves make tiny clicking noises, so you'll know that something is going on down there, but the system responds so quickly that the hand-off between open and closed feels seamless. I was lulled into believing that nothing was going on until I realized that every root and rock that I was rolling over on my way up the mountain felt like it was the same size. They weren't.



G-limited: Live Valve opens when G-forces hit its preset threshold with such precision that all initial impacts feel about the same. I was banging into an array of rocks and roots ranging in size up to five inches, but at the grips, my 36 fork's four-G threshold setting made the bike feel like I was rolling over a continuous web of small, two-inch-diameter (50mm) roots. Adjust the G-force threshold up or down (Fox let me experiment with Live Valve settings), and you'll feel a proportionate change in the bike's small-bump sensitivity. After Live Valve's latching solenoids open, however, the quality of your suspension is entirely dictated by your air-pressure and damping choices, and the bike's kinematics. Or is it?



Improved suspension action: One might assume that, because Live valve can only toggle a percentage of your shock and fork's low-speed compression damping, that it could not significantly improve the performance of your suspension outside of its pedaling feel. Live Valve's timing algorithms, however, greatly enhance the way the suspension responds while climbing. Live Valve manages to maintain the bike's ride height, so beyond the actual grade of the trail, there was never a perceptible change in the fore/aft balance of the suspension and its ride height as I made transitions from flat to climbing.

It took a while before I stopped pausing momentarily to transfer my saddle position forwards at the onset of every climb. That was no longer a necessity. The only times I needed to break my pedaling cadence and move my weight around on the saddle was for more technical ascents or steep, punchy climbs - and even then, the stability the system added to my already sharp climbing Mach 5.5 was remarkable. I also could pedal more smoothly up chunky section because the controller allows the fork and shock to respond independently in climb mode, which keeps the rear wheel driving, and the front of the bike tracking, instead of skipping over the chunder.



Another surprising improvement to the suspension's action was the 'free-fall' mode. I never realized how often I was airborne while riding at pace over relatively smooth trails until I started using Live Valve. The controller can sense and react to a tiny drop, which dramatically smooths the medium-sized G-outs that most perceive as bothersome trail chatter. My bike felt more glued to the ground at speed. Corner entries and hard braking felt more precise.

The Live Valve litmus test occurs when you switch it off (or run out of juice in the battery, as I did once). Every time I switched off the system for back-to-back comparison runs, it only took a minute or so before I wanted to pull over and turn it back on. Live Valve defaults to open mode, which still provided sprite pedaling action aboard the Mach 5.5, but once you know something you can't un-know it.


Can You Live Without It?

Live Valve is going to find its home on high-performance trail bikes with generous amounts of wheel travel that are owned by enthusiast-level riders who already own a high-end machine and want a better bike for their next purchase. There are a handful of trail bikes presently available that pedal efficiently without suspension aids and Pivot's Mach 5.5 is among them. No, you don't need Live Valve to ride at the highest level, but if you have the money to burn, you'll get more performance for your dollar from Live Valve than you could hope to squeeze from electric shifting, a fancy carbon wheelset or even a sequential-shifting gearbox.


What I Liked Most


Live Valve Can't Fix Stupid

What Live Valve can't do is compensate for a poorly set up fork or shock. If your suspension is pumped up to a zillion PSI and plugged with air-volume spacers, or if your dials are screwed to their maximum positions, you are on your own. Live Valve will happily toggle your low-speed compression circuits at precisely the right moments, but at best, your ride quality will only be less worse. Live Valve turns in its best performance when the suspension is biased to enhance traction and match the rider's technical skill-set.


Pinkbike's Take:

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