4iiii Acquires STAC Performance, Makers of Near-Silent Trainers (and other products)


The consolidation in the power meter and trainer industry continues this year, with 4iiii announcing today they’ve completed the acquisition of STAC Performance, which you’ll remember makes the virtually silent trainer that I rode inside our baby nursery.  STAC also though has their hands in a few other bowls of pudding, including aerodynamic related testing and bike fitting. Also, like their new Alberta-based owners, STAC is also from the continent’s snow-tuque, themselves based in Ontario.

Now, this deal is actually far more fascinating than might first meet the eye. After all, STAC isn’t a very large company – only about half a dozen employees. And 4iiii isn’t very big either, though 4iiii generally fights above their weight in terms of various industry OEM deals (for example, they’re behind the technology on the Specialized power meter). And of course, the founder of 4iiii was the one who invented ANT+. So – they generally have an eye for emerging tech. The company didn’t clarify in the announcement terms if STAC would add any extra vowels to their name post-acquisition.

What they bought:

STAC has been around a few years now, with their STAC Zero, and then STAC Zero Halcyon trainer. Both units used magnets to allow you to have a virtually silent trainer. Like one of those funky people movers at Disney World, the STAC Zero trainer used magnetic forces against your metal wheel rim to apply pressure to increase resistance – all without touching the wheel, thus, no noise. The Halcyon version kicked it up a notch and allowed the resistance to be computer/app controllable using ANT+ FE-C and Bluetooth Smart FTMS. In other words, you could ride Zwift and feel the hills, or TrainerRoad and get the perfect ERG workout (actually, it was scary-fast how quickly it could change resistance).

All of that was well and great, except that one of the key issues for the company was honestly the aesthetic design of the trainers. While bright orange is great for traffic cones trying to avoid getting hit by a school bus, it’s less ideal to place in your fancy Peloton-ready living room (or yacht). And the STAC Zero industrial design was…well…very industrial. Of course, with the company almost entirely engineers – you sorta might expect that trade-off. And for many people, they were happy to make the trade-off of pretty to gain quiet.

But the challenges extended beyond that – namely – the rear wheel itself. You had to place weights in it to get really good road feel, and then it became cumbersome to move your bike in and out (since you had to remove the weights). So it was great if you had a second bike to just leave there, or a longer-term bike for the winter. But swapping it quickly like most direct drive trainers? Not so much.

Still, there’s a lot of promise in what STAC has. 4iiii has shown it can iterate and get numerous products to market fairly quickly. They have deep ties to manufacturing facilities, both inside Canada and out – something that STAC really lacked.

But that wasn’t the only product category STAC was involved in. They also had their virtual wind tunnel platform, which 4iiii says they’ll not only continue, but also spend some cash to drive some significant updates in that area. At present, the use case and target market was perhaps a bit too broad, whereas going forward the company says the main goal there will be focusing specifically on bike fitters to enable the best possible fit that’s also the most aerodynamic. All without ever having to visit a wind tunnel.


As we see more and more convergence between the power meter world and the aero world, this is a logical partnership. After all, we saw Garmin (maker of Vector power meter pedals) purchase Alphamantis (maker of cycling aero tech), and other companies are also slowly circling around the aero/power realm to see which startups are ripe for an easy pickup that matches their existing products.


Above left, Andrew Buckrell (CEO of STAC), and right, Kip Fyfe (CEO of 4iiii), signing the landmark sports tech deal at what appears to be Boston Pizza, judging by the pizza oven behind Andrew. Anytime a pizza oven is involved, I’m a fan (Square photo Credit: 4iiii/Newswire). Note that all employees of STAC will relocate to the greater Calgary area this summer, where 4iiii has their headquarters in Cochrane, Alberta.

STAC says that all existing customers will continue to receive support and such just like normal, there’s no changes to that. Given 4iiii bought STAC to expand their trainer business, it’s logical that we wouldn’t see any (negative) changes there.

Finally – some may wonder whether I see this type of consolidation as a good thing – and in this case, I think the answer is a resounding yes. I’m not sure if long-term STAC would have been able to go it solo, especially with the other larger trainer companies in the midst of consolidation (or being for sale). I think if 4iiii plays its cards right over the next 12-18 months, it could find itself as a legit and well-known option for indoor trainers. Of course, that’s going to take some good product engineering and marketing, but 4iiii is well positioned to do that. The alternative is that I think STAC would have had trouble competing, given the funding others have.

Going Forward:

Of course, any time a company makes an acquisition, there’s plenty of questions about the current products – but even more about the future products. When I chatted with 4iiii founder Kip Fyfe about this last month, he noted a few things. First, there’s a surprising number of ways that both companies can leverage each other’s technology. This definitely isn’t all about just adding a trainer brand to 4iii’s

For example, STAC would likely look to leverage some of the experience that 4iiii has around strain gauge technology to increase accuracy of the products while reducing some of the more cumbersome aspects of the current trainers (note that I found when properly set up, the current trainers were very accurate, but the ‘when properly configured’ part could be challenging).  And 4iiii thinks there’s ways beyond the manufacturing assistance I noted earlier to improve about the STAC product lineup.

Yes, line-up. As in, more than just the current two products. For that, Kip says we’ll need to wait till Eurobike to see what they’ve come up with. If they can execute on what they’ve sketched out for me on a napkin, it could be a compelling offering that’s unique in the market. But that’s all they’re willing to share for now. Executing on any vision is always the tough part.

Eurobike returns back to the first week of September this year, and is the typical industry place that we see new trainer announcements occur (or in some cases, be finalized and shipping by then).

With that – thanks for reading!


Hopefully, you found this post useful. The website is really a labor of love, so please consider becoming a DC RAINMAKER Supporter. This gets you an ad-free experience, and access to our (mostly) bi-monthly behind-the-scenes video series of “Shed Talkin’”.

Support DCRainMaker - Shop on Amazon

Otherwise, perhaps consider using the below link if shopping on Amazon. As an Amazon Associate, I earn from qualifying purchases. It doesn’t cost you anything extra, but your purchases help support this website a lot. It could simply be buying toilet paper, or this pizza oven we use and love.

Post a Comment

Your email address will not be published. Required fields are marked.
If you would like a profile picture, simply register at Gravatar, which works here on DCR and across the web.

Click here to Subscribe without commenting

Add a picture



  1. Neo.e92

    Thanks for this news, Ray.

    Based on what you have been posting lately about industry consolidation on our neck of the woods, IMO, this is the most that really makes sense specially for two small-to- mid-sized companies.

    Let’s hope they succeed as we need more of these David’s battling the goliaths of the industry.

  2. Chader

    Very good for both involved. I am curious if/when we will see a direct-drive trainer based on the STAC elements? I think it could lead to an interesting variation on the current market that may well be less expensive for similar capabilities. Interesting times.

  3. fisao

    I do not mind mergers and acquisitions. However, I would be very grateful if Garmin and Tacx could please work on finally releasing the Garmin/tacx neo smart bike as soon as possible. /sob /crying

  4. Tim

    Step 1 – Per the comment by Chader, make it a direct drive trainer. Put a flywheel and cassette on it instead of using wheel weights. This would leverage their existing resistance unit design and complete silence, and eliminate the hassle of installing weights on the wheel.
    Step 2 – Per Ray’s comments, leverage 4iiii’s expertise in measuring power and in developing software to make the accuracy, response, and user experience great.
    Step 3 – Get the Industrial Engineers to make it more robust and visually appealing. Make it look more like a high-end trainer, and less like a $99 trainer with cantilever brake arms added on.
    Step 4 – Get the Marketing Department started on a data-supported product announcement for Eurobike. If they can execute their other steps this could/should be a high-accuracy, fast response, silent trainer, at a potentially lower price point.

    • JD

      For all practical purposes the STAC Halcyon is a direct-drive smart trainer.
      You are directly spinning a wheel with electronically controlled resistance.
      Add too much direct-drive “baggage” to the design and you’ll lose portability.
      If they decide to spiff things up and branch out I suggest two models — Halcyon GO with focus on lightweight portability and Halcyon STAY for fitness cave enthusiasts. GO or STAY, your pick.

      For convenience you only need a spare wheel with the wheel weights mounted. It can be an old junky wheel as long as it’s true. Tire/tube is optional but the heavier the wheel the better.
      That being said I no longer use the wheel weights. I think they are of benefit to Zwifters and road simulation apps, but are completely unnecessary for ERG workouts especially if you are a lightweight (like me).

    • Chader

      They can keep the standard wheel-on design, and add a new product in the form of a wheel-off design. I think they can broaden the product line easily to offer at least 2 key designs at different price points with different feature sets.

      True, there is no “wheel slip” issue present like you get with the typical wheel-on trainer that is driven via a rubber tire to a roller. But the issue of inertia and the wheel weight solution has it’s own set of issues.

      Those might be possible to solve via a wheel-off design. I think there are multiple design options for this concept and it may well have some serious advantages over other wheel-off designs. The silent operation and possibility of use with out power is only matched by the Neo/2 at the moment. So I see them with a decent opportunity, especially if they can undercut the premium price point in the process.

  5. Andrew M


    Not sure if this is the right place to post this question, but what do you think the lead time will be before we start seeing power meters compatible with Shimano’s new GRX gravel groupset?

    • The GRX is Hollowtech II, so… any of the existing left-side Hollowtech II power meters will work. Drive side might take a while.

    • Andrew M

      I thought I read it was forged. So I went back and checked more carefully. You are right – the RX810 is Hollowtech, but the RX600 is forged.

  6. Paul S.

    I upgraded my Kickstarter Zero to a Halcyon last year, and I found that I didn’t need the wheel weights, and didn’t put them on. They seemed to be modulating the magnets (you could look down and see them moving slightly) to eliminate the need. But, yeah, I set it up in November and took it down early April. I wouldn’t want to pop the bike on and off all the time. It is kind of finicky to set up. On the few days I needed an indoor trainer in the last month, I used my Kreitler rollers. I’ll set the STAC up again mid to late November.

    • JD

      It is very easy to pop the bike off and on. I do it several times a week depending on the weather and ride time available.
      Once you have the wheel centered (app function), lock the axle cup on the cassette side then loosen the other side when you want to remove the bike. Pop the bike back in when needed, snug the axle cup on that side, and you’re back to center, ready to ride. Off or on in less than a minute. At this point I know how many turns of the knob that takes.
      I also nixed the wheel weights. I don’t think you need them for ERG workouts.
      I only use a smart trainer for ERG workouts and occasional RAMP test by entering resistance mode then spinning up a few RPM every minute or two until I can’t take it anymore.

  7. I am curious to see if another reason for the aquisition is to leverage the hardware to use on indoor cycling bikes. 4iiii partnered with Schwinn to put power on their indoor cycling bikes and I have been waiting for someone to add automatic resistance instead of turning a knob to engage the magnets for resistance. With Peloton’s emergence it would seem like a natural move into that space to retrofit IC bikes like Schwinn, Stages, Spinning etc., to smart bikes and leverage that technology…

  8. Tizzkedk

    Interested to see if trainer road, xert or today’s plan gets bought. That could be a great buy for a company that needs a training platform in their portfolio.

  9. Anirudh

    If 4iiii also acquire a smaller manufacturer of bike computers like Sigma, and perhaps even a smaller wearable company like Coros, they might be able to better take on Wahoo and Garmin.

    • It would likely be tough for 4iiii to acquire Sigma (at 100 employees – the same as Wahoo). COROS is funny, because they are so heavily funded from Chinese backers, that they too have far greater aspirations than their sales might vouch for.

  10. Brian Faure

    Yesterday my 4iiii powermeter finally flagged me of a firmware update…it now adds the location feature that Ray had been talking about.

  11. Lee

    Just received an email from 4iiii saying all remaining 2018 Stac trainers are 50% off

    • Tizzledk

      Wow…..thats big!!

    • JD

      Yikes! That means $375 USD for a smart trainer.
      I’ve ridden the Halcyon 3-7x/week since February this year. Now that Spring has sprung it’s my go to ride whenever the weather is dismal.
      As DCR mentions you need to tinker a bit during initial setup, but once dialed in the unit has performed well for me (disc gravel bike plus RAP 12mm trainer thru-axle).
      You get used to the “sock slip” transitions that GPlama found odd. It’s a fraction of a second and depends on the type of interval change. There’s is an app function to adjust transitions but I use the default setting.
      The benefits of a STAC Zero Halcyon include silent operation (other than your drive train), automatic calibration every time you hop on, and the unit folds flat for storage or travel.
      I picked up a 20″ pizza delivery bag which holds everything, but I no longer pack the wheel weights as I found ERG workouts are fine without the weights.
      The unit also operates up to 10 hours on a battery charge and you can preload a default workout if you want.

  12. Tod

    “signing the landmark sports tech deal at what appears to be Boston Pizza, judging by the pizza oven behind Andrew.”

    Boston Pizza is definitely not that fancy. ;)

  13. Cougie

    Love my Stac Zero. Never thought anything of the industrial design. My turbo is in the garage so aesthetics aren’t important. Function is. I’m using it with a disc wheel and never needed the weights to make it realistic.

    So quiet that my wife doesn’t even hear me turboing. Usually the whole street would be able to hear.

    Very happy with it and good luck to the company.

  14. Dan

    You said “when properly set up, the current trainers were very accurate, but the ‘when properly configured’ part could be challenging” – so I’ll bring up my own challenges with it.

    I got a STAC Zero in the initial wave of trainers; I was excited about getting a silent zero-tire-wear trainer with a power sensor. But I couldn’t ever get it to work. If I got the magnets spaced narrowly enough to give any resistance, then no matter how hard I tried to secure them, within a minute of starting to pedal, they’d fasten on to the side of my rims with a KLONK, with the rim grinding against the magnet’s covering.

    Additionally, the rear wheel rim on one of my two bikes apparently has very different magnetic properties at the joint, causing the bike and trainer to give an easily felt THUMP every time that joint passes the magnets. And the power sensor seemed to have trouble pairing and staying on.

    I wrote this off as a Kickstarter failure, money down the drain. I suppose I should have pursued more support options or a return, but the reply I got the one time I contacted them for support gave me the impression they were still too much in the “fragile start-up” phase to really do much for me, and I was very busy at the time. Maybe I should revisit that, and though they say support won’t be affected by the acquisition I have to wonder.

    What kind of success have others had with the Zero and with STAC support? Any recommendations as to what I should do?

    • Paul S.

      I wasn’t a fan of the Zero’s quick release mechanism for keeping the magnets off the rim, and eventually I put zip ties on mine to physically keep them off the rim. In my case, though, the ultimate problem was that the tire I was using had wire (probably steel) beads, so the magnets were attracted to them. Once I switched to foldable tires, I had no further problems.

      Your joint problem seems very odd, but it might have the same root cause. The wheel weights should have helped with this. The Zero itself doesn’t rely on any magnetic properties of the rim, but if whatever is joining the join is magnetic or has different conductivity that might cause problems.

      I upgraded my Kickstarter Zero to a Halcyon. The actuators moving the magnets are plenty strong enough to keep them off the rim, and I actually no longer need the wheel weights.

    • JD

      What you describe sounds like their early model trainer and not the Halcyon smart trainer. I only have experience with the Halcyon which I purchased during their promo period.
      STAC Zero support has been great.

      Your wheel rim cannot contain any steel pins or the resistance magnets won’t work. A simple test is to run a strong magnet around the rim. You shouldn’t feel anything magnetic. A metal beaded tire is also a no-no.
      See these links for more info:
      link to staczero.com
      link to stacperformance.zendesk.com
      link to stacperformance.zendesk.com

      If your early model can be upgraded with a Halcyon kit that is what I recommend you do. The Halcyon controller adjusts the magnets automatically.
      Setup adjustment videos are located here: link to staczero.com

      As I mentioned in my other post once setup correctly with supported rim type the unit performs as you’d expect. Just hop on and ride.

      I ride in top gear for ERG workouts and don’t use the wheel weights.

  15. Nat Faulkner

    Tuque — it is actually spelled Toque

  16. Steve

    I’ve had my Halcyon for nearly two years now and really like it, using it almost exclusively for Sim rides on Rouvy. What’s nice about the Halcyon is that it is compatible with my wife’s six speed tourer, and my two retro 7 speed road bikes, not something that would be true of the direct drive alternatives. About a year ago it bricked itself during a firmware update and 4iiii/Stac were superb and helped me get it up and running with the improved 2006 firmware which I have set to give me up to 10% hill resistance. Top marks 10/10 A+++ etc.

    Three weeks ago I was pedalling away as you do, and the resistance on a small rise starts to randomly vary then all but disappears. I soon realised that one of the linear actuators that moves the magnets has failed in an open position. I contacted Stac Support only to receive an e-mail that told me that due to Covid-19, support had been withdrawn for the Stac product line apart from claims under the 12 month warranty, and that there is specifically no individual problem solving or stock of spare parts. Not wanting a £700 door stop, I noticed that the nice people at Stac had put the OEM part number on the Actuonix linear actuator, and I was able to source one next day from RS Components (UK) for the princely sum of £100. This actuator was an almost exact replacement for the Stac original, but looks like it is an exact match for those on later models. I had to substitute a supplied bolt and Nyloc nut for the circlipped pin at one end, and I was up and pedalling again.

    Last week I was pedalling away again thinking how well the Halcyon was working when I felt the resistance randomly vary and then stay the same. I assumed it was Nyloc nut related, but no it was the other Stac actuator that had failed but with its magnet close to the rim so able to provide 240W at 90RPM so very rideable. The second failure in three weeks could be no coincidence so decided to go direct to Actuonix who were really helpful. Although not aware of the Stac Zero application, they did tell me that the service life on the PQ12 motor was 125 hours, and made me a very generous one off offer on up to nine actuators. My actuators actually managed 3500 miles so about 200 hours at 17mph average, so five of the little blighters are winging their way to me from Western Canada, one for the second repair and two pairs as spares which should keep me and the Halcyon going for another six years.

    When I contacted 4iiii the reply just said that the promised Fliiiiight upgrade for the Stac Zero was still not available. Let’s hope they have a longer lasting solution to moving the magnets on the Fliiiiiiiiight!