Fox Live Valve Launches, but what is it?

After years of behind the scenes work and glimpsed prototypes, the Fox Live Valve system is finally ready to be released to the world. Around the time you read this, bikes with LiveValve fitted will be heading towards bike shops around the planet.

But what is it? What does it do? And do you need it? Let’s dig in…

What is Fox Live Valve?
Essentially, LiveValve is an electronic control for your bike’s suspension system that uses bump and tilt sensors on the frame and forks to work out what terrain you’re in and turn your suspension on and off to suit.

Haven’t we had this all before?

If you have a long memory, you’ll remember the Fox Terralogic fork, back in 2004 or so, plus the collaboration with Specialized and its Brain shocks found initially on the full suspension Epic. In those cases, the fork, or shock’s on/off valve was controlled by an effective, but crude, brass weight. Later on came the Fox iCTD system, where a rider-actuated switch turned the suspension on or off using an electronic relay to open or close the system.

And now? What’s this?

Now, though, comes the Fox Live Valve system. While the general idea is the same (an electric ‘switch’ controls the suspension’s on/off setting), the control of it is much more sophisticated and involves no rider input at all.

 

At the heart of the system is the battery and brain of the Live Valve system. This is the head unit, housing the on/off switch and the sensitivity setting. This unit is securely fitted – either to just below the bottle cage, or near the piggyback of the shock. It’s easy to remove if needed, though it can be charged in situ too. From here, wires go to the rear shock, to the top cap of the fork, the sensor on the fork brace and to the sensor next to the rear axle.

What does it not do?
Live Valve purpose is simple, though the electronics behind it aren’t. It’s an electrical way of controlling the on/off switch on the suspension. What it won’t do is adjust your compression damping, or your spring rate or your air pressure. It simply turns the lockout/pedal platform switch on the fork and shock on and off. How stiff that ‘on’ position is, is mostly set by the bike manufacturer (in conjunction with Fox) based on the bike’s intended use and design. How soft the bike is when the system is ‘off’ (this is going to get confusing, but bear with me) is up to the user and is set up, with sag, in the usual way.

How does it do it?
Live Valve has three sensors: One fitted to the mudguard mounts on the fork brace, one on the head unit itself and one by the rear axle, usually incorporated into the chainstay, or in the rear brake mount itself. These are scanning the terrain, feeling for bumps and changes in the terrain, 1000 times a second. When a bump is felt, a message is sent to the head unit and within three milliseconds, an electric servo in the fork (and then in the rear shock) opens the suspension system. This speed is the reason for the cables and why Fox says it couldn’t use Bluetooth or other wireless technology to link the sensors together.

And now comes the more clever bit.
When that first bump is felt, a timer is started. On the old Terralogic forks, once a bump had dislodged the brass weight, opening the damping circuit, a spring started pushing back on it until it closed again. If it hit another bump, it remained open. With Live Valve, an electronic timer is started, but also, a tilt sensor in the head unit measures the angle of the terrain. If the bike is climbing, then the timer is only short (let’s say half a second) before it closes the system again, so that maximum efficiency is retained on the climb. If the bike is descending, then it’s likely that the bike will hit more bumps, so the timer is set to a second or more, keeping the system open and ready for more bumps. On the flat, the timing is somewhere between the two. These three times, plus the force taken to open the system, and the tilt angles that determine if the bike is going up or downhill, are all set by the manufacturer at the factory.

Won’t the battery go flat on rockier terrain?
In either the open or closed positions, the electromagnet uses no extra power. It only uses power to switch between those states. Fox reckons that the battery should last for at least 16 hours of riding on a charge. And even if you’ve forgotten to charge your bike, a 20 minute charge while you’re getting changed is enough to ride for a couple of hours or more. And if the battery goes flat on a ride? You’re just left with a suspension bike, with regular damping, just without the ability to lock it out. Not the end of the world.

What if I wheelie and hit a bump with only my rear wheel?
The system has three sensors – in the fork, head unit and rear axle. The rear sensor controls the rear shock (the fork sensor does fork and rear shock) so if you wheelie over a bump, it’ll feel it and open the system.

What about if I’m in the air?
What if you’ve launched off a jump. You’re in the air, which has no bumps in it. Will that lock out the fork for landing? No, the system has a tilt sensor in it and it can tell if you’re freefalling – at which point it opens the system, ready for a squishy landing.

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What if I’m not a hard, or heavy rider?
There are five settings on the head unit that determine how sensitive the system is to bumps. On its hardest, the bike will try to remain locked out unless the rider hits some significant bumps. On its softest setting, the system will likely be open for much of the time. There’s a small LED that lights up when the system is open, showing that it’s open, but also showing which of the five modes it’s in. It’s a simple button press to cycle through the different settings.

Who’s it for?
Fox (as you might expect) says that it’s up to the manufacturers to decide what bikes and travel to design Live Valve for, but Fox reckons that it’ll be in the mid-travel trail bike category that it’ll see the most relevant use. For riders who might be on a smooth forest trail one minute, then dropping into a rock garden the next. Or for an enduro racer who pops out of one woody singletrack section, sprints up a fire road for 50m before continuing the descent. Those riders may not have the time, energy (or memory… ahem) to lock and unlock their suspension. They’ll often just suck up the bouncy bike for the brief time they’re sprinting on the flat (or they’ll lock it out and then forget to unlock it for the descent…)

Fox now imagines that these riders can hop on their bike, ride up hill (on or off road), drop into the trails with suspension working, ride the smoother bits with suspension locked back out, but ready (in 3m/s…) if there’s a drop, or rock garden just round any corner.

What’s the damage?
Weight wise, on a bike like a Scott Genius, the complete system (wires and all) weighs 144g over normal. In terms of cost, there’s not surprisingly, a price tag that comes with it. Early reports reckon that Live Valve will add €1800 to the price of a similar, manual, full suspension bike. Or you can buy the whole system (fork, shock, head unit and sensors) for €3000 to fit to your own bike (assuming you have existing mounts for the rear sensor and room to route all of those wires.)

We’ll have a full write up of our initial impressions on another story, but in the meantime, here’s a load more detail for you:
www.ridefox.com

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