2013 Fox prototype electronic suspension with CD Climb Descend damping and lockout powered by a Shimano Di2 battery

There’s been a bit of speculation floating around about the electronics on Geoff Kabush’s mountain bikes this year. After a little squish test, some button pushing and a lot of photos, we think we’re getting closer to the truth here.

First, a little background on the speculation: There’s a Shimano Di2 battery on the downtube, and Fox and Shimano have a good working history, so a collaboration wouldn’t be surprising. As for electronics, in 2010 Fox hired Dr. David Batterbee, who in the past created an electronic terrain sensing mountain bike suspension using magnetorheological fluid dampers.

Shimano’s rep said they’re not able to comment, and we haven’t heard back from Fox (we’ll update if we do). Pics and analysis after the break…

2013 Fox prototype electronic suspension with CD Climb Descend damping and lockout powered by a Shimano Di2 battery

First up, the news here is that Kabush’s bike is running an electronic something on both the fork and the shock, and both are controlled by a single lever. Both fork and shock have one wire coming from the battery and one from the controller. This suggests that the Di2 battery is merely there to power the system rather as a matter of convenience. Why develop a battery and mount if there’s one already out there? Of course, it would also be convenient if you were running K-Edge’s Ki2 system or if Shimano develops an electronic MTB group in the future.

2013 Fox prototype electronic suspension with CD Climb Descend damping and lockout powered by a Shimano Di2 battery

The fork itself has very little to show, likely because there’s room inside the stanchion for any brains, servos, etc. The Shock, however, had its system external and the control box was mounted such that a servo motor could rotate a damping valve where the new CTD compression settings lever is. What’s presumably the rebound lever is still there, likely just with an extended rod to make it still work. The knob is the same as what’s on their new shocks, just devoid of graphics. That means it could be for tuning what that box actually does.

2013 Fox prototype electronic suspension with CD Climb Descend damping and lockout powered by a Shimano Di2 battery

Fox’s new suspension line up is built around their new CTD (Climb – Trail – Descend) compression damping. Notice the letters following Float only say CD.

2013 Fox prototype electronic suspension with CD Climb Descend damping and lockout powered by a Shimano Di2 battery

The lever was a rotating bezel between the I-Spec brake/shifter clamp and the grip. It had only two positions, one for each of the two letters on the can. Flipping it back and forth I could hear little motors doing something. My guess is rotating a valve opened or closed, much as you would do if you reached down and turned the knob on the fork crown or flipped the CTD switch.

This could just be an electronic lockout or compression mode switch considering when it was in the “C” mode, it was completely and totally locked. As in my 180+ pounds couldn’t budge it, not even a blowoff. When in “D” mode, the suspension moved.

In this case, even when open Kabush’s suspension barely moved, but he’s a pro and pros like their suspension firm. And Sea Otter’s XC course is about as rough as my sidewalk. Without riding it and taking it off a few drops, there’s no way to tell if there’s more active (ie. computer controlled, terrain sensing) suspension technology hidden in there. It’s certainly possible.

Even if this amounts to nothing more than a glorified compression setting switch, it’s a bazillion times better looking than their mechanical CTD remote. It doesn’t stretch the imagination to think they could add a third “Trail” segment to the electronic switch.

2013 Fox prototype electronic suspension with CD Climb Descend damping and lockout powered by a Shimano Di2 battery

UPDATE: Fox’s PR man Mark Jordan chimed in with the not unexpected statement about not being able to make a statement on prototypes: “FOX is always developing new products through its Racing Application Development (RAD) program. FOX strongly believes that racing provides the best environment for testing and all future product developments go through this program in one form or another. This may expose prototype products to the public before we are ready to communicate about them.”

What do you think?


  1. Mikey D on

    I’m tired of more and more switches…AArrgggHH!! just give me suspension that works. This is getting more complicated the an airplane cockpit. Am I going to have to get clearance every time I was to catch some air? and how many buttons will I have to press whenever I want to switch from climbing to descending?

  2. Brandon on

    I’d try just about any new equipment once. If it works well, I think it could be awesome. But, I also love Di2. I can understand why some people wouldn’t care for it, but I’m diggin’ it.

    Make it an option, but not a requirement, and I think we’re set.

  3. Al on

    Not to be that guy… but this is just one example of how the bike industry is headed in the completely wrong direction. Companies are constantly pouring money into developing more and more complicated systems that have such a high price tag only a select few of us will ever be able to afford. There needs to be a shift in focus toward refining the manufacturing process of what we have now so high quality bikes can become more accessible to everyone who wants to ride. The main turn off for anyone new to the sport is the overhead associated with getting started, specifically buying the bike. Companies need to work on bringing prices down and expanding their market. It will do way more for this sport then developing some fancy new electronic suspension only a handful of us will be able to buy ever will.

  4. g on

    Why are we complaining? This is top level racing, think of it like Superbikes or F1, the sky is the limit, fastest person and bike wins. While they are at it link it to the GPS so the fork and shock adjust to the rider’s position on the course. Mechatronic stuff won some Superbike competitions in 2007 but was outlawed in 2008. Balls out, let’s see what they can do. In regards to trickle down…I dare say the 800-1200 dollar bike today would blow the doors off something twice as much only a few years ago right?

    Lastly, best sideburns in racing needs a bad ass suspension set up.


    Over-kill. I want performance, reliability, user-serviceability and durability. Not bunch of wires and microchips strapped to my ride.
    And what Al said.

  6. Androo on

    @ Al
    To be fair, a 9-speed Alivio derailleur and shifter set today works better than the XTRs you’d have spend 5 times more for 10 years ago. What you’re describing is already here, companies are just pushing the high end as much as they can in pursuit of decent margins for the people who are obsessed with the very best.

    You can spend $700 on a hardtail now that would put just about any mountain bike at any price 15 years ago to shame…

  7. smartest on

    Bring on the electronics. that’s what most of the riding public wants, despite this annoying bunch of nay-sayers. If it works and it’s better then I want it. Can I open the programing on my PC and customize it to my likes? how cool would that be? I love technology!

  8. Michael on

    @Androo. Have to disagree there, buddy. I had XTR in the late 90s and into 2000s – it was amazing. How would today’s alivio compete with 4-ball bearing 950 XTR shifters? It wouldn’t. I understand the point that you are making – just be aware that 10-15 year old gear can actually be awesome.

    Perhaps all of the gizmo-gadgetry we are seeing these days is a recognition that frames, shocks and drivetrains have already reached the end of their development and they are just descibed differently by the marketing department to entice new sales. E.g. Specialized and their yearly 30% stiffer and lighter advancements that they have made since 1996.

  9. James S on

    The next big thing will be super wide handlebars so you can add a dropper switch, front and rear suspension lockout switches, remote compression and rebound switches, and a switch for that contraption that changes the tire pressure on the fly.

    I just swapped out my freeride bike with dropper post to a slacked out hardtail single speed because I realized I was pushing too many danged buttons. If I wanted to push buttons, I could just be one of those idiots texting all day. (Or I could spend too much time on the internet….)

  10. Adam on

    I say bring it on! Why is it that in the bike world we have people continually trying to defend the technologies of the past. Ya xtr rules and ya it always has, but why in the world are all you people looking at this blog? It because we all love bikes and we love the new shinny and lite parts that come out year after year. You know it’s true, how many times have you been to the bike shop to druel this week? I want the Lamborgini, you can tirelessly defend the ford escorts but they will never get you laid, just remember that!

  11. gringo on

    To all the nay sayers:
    Please remember this is the top of the top World Cup racing spec. do you complain when your little Honda doesn’t accelerate like a top fuel dragster or corner like a F1 car?
    Of course you don’t.
    Of course this stuff is complicated and expensive, but do you really think the sport would be better if every sinlge rider rode around on LX or X5?

    Remember two things:
    1. Even if you could afford it (you can’t) they still wouldn’t sell it to you.
    2. This is literally the state of the art in MTB suspension.

  12. Speed565 on

    I think it’s a great idea and it will simplify the suspention. You will need just to find 3 different settings once. Then only to switch them on handlebar – all at once – front and rear. it should hold on battery a lot longer, then self adjusting suspetion from cannondale.

  13. MattGvt on

    If they are actually using magnets and electric current to vary fork performance based on terrain, that’s really really cool. If it’s just a little servo motor they’ve attached to the knob that we all already have on our forks, then that is super lame and not (to me) a true advance.

  14. Angus on

    If Androo has some 10 year old XTR, I’d be happy to swap some new Alivio… In fact I’m riding 8 year old XTR as it is and it’s still shifting perfectly. It’s the quality of the materials and the use of bearings where the cheaper groups get bushings that make it cost so much, but it also means it just goes on and on working. Lets hope the electronic stuff is similarly robust – only time will tell, but I think it could be if they build it right.

  15. tifosi on

    Future Di2 XTR collaboration? How about auto lockout when in the granny gear, and more progressive travel when in the biggest gear? The idea of an auto adjusting suspension based partly on rider gear ratios (thus presumed speed), sensor based terrain input, and with rider (pilot) override would be pretty nice.

    But I am still waiting for the rumored power meter from Shimano that puts you in the perfect gear based on your measured power output and effieciency…all with Di2.

  16. DSull on

    Why the need to bash something just because it isn’t for you? I think it looks cool and sounds like a neat idea–even though I’m not interested in ever running it, I can appreciate a new idea.

    And for the love of all that is decent–quit yer biching about “all these levers and buttons”!!!!! I understand the beauty and appeal of an uncluttered system, but you’re acting like 2 derailleurs to shift, a dropper post lever and possible suspension adjust switch is “so many buttons and levers”. Seriously people, it’s not that complicated.

  17. Ray on

    Didn’t Proflex/Noleen have electronically controlled dampers years ago? My memory is it had a sensor that monitered shaft movement and adjusted damping to suit.

  18. dk on

    I second the 5.7 comment. My 5.7 carbon is OMG good at everything and I got 26.5 lbs without trying and with dropper post.


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