In the turbo trainer market, several big names come to mind, and Tacx is certainly one of them. Acquired by Garmin in 2019, the brand is known for its wide range of indoor trainers which includes everything from its entry-level Antares rollers to the premium Neo Smart Bike with all its bells and whistles.
The Tacx Flux S sits in the middle of Tacx’s line of smart trainers as the most affordable direct-drive smart trainer after the Flux 2 and Neo 2T. Costing less than half the price of the latter, the Flux S represents the brand’s answer to making smart indoor trainers as affordable and accessible as possible. With price being its key USP – especially compared to the higher tier Flux 2 – the Flux S is aimed at those who take their indoor cycling to the next level without needing to go all the way, and it undermines considerably. many competitors such as the Elite Suito and the Wahoo Kickr Core. That said, it does have some serious competition in the form of Elite’s Zumo, which is not only cheaper, but is also compatible with 142x12mm thru axles.
But does “affordable” mean cheap and therefore a bad choice in the long run, or does it offer enough value for money to be competitive among the best turbo trainers?
If you’re new to indoor cycling, or are going from a dumb trainer, is the Flux S worth your hard-earned money? After spending the last six months training with one of them, here’s what we think.
Design and aesthetics
When you unpack the Tacx Flux S, the first thing you will notice is its weight. It requires a little assembly but not a lot, and with very little effort. The unit is made up of two parts: the main body and the feet. In the box, next to the trainer, you are provided with an 8mm Allen key, a quick release axle and a manual.
The cassette is not included, so you will need to provide your own, and you will also need to provide your own chain whip and locking tool to attach it. The Flux S is immediately compatible with Shimano and SRAM eight- to 11-speed cassettes, and you can purchase an SRAM XDR driver or Campagnolo compatible body separately. The supplied quick-release axle can work with widths of 142mm and 148mm, and a 135x10mm adapter is available for cyclocross and mountain bikes.
We recommend installing the cassette before the feet, as it’s much easier to lay the main body on its side and slide the sprockets into place. From there it is easy to tie up the legs and secure them.
The leg design is clever, forming a “V” shape that provides lateral support. Once strapped in, provided you’re on stable ground, they won’t budge at all, making the Flux S a sturdy and sturdy indoor trainer, albeit quite heavy at 20.9kg. It is also quite large, measuring 67cm long, 46cm high and 64cm wide.
Once assembled, it’s time to put the Flux S in place, and that’s when you realize it doesn’t have a carrying handle, or really anything that you can easily grab from. one hand in order to move it from one place to another. Instead, it’s a whole body effort to lift the thing up and put it in a place where it will likely stay until the end of time, because you won’t be seeing it all again anytime soon. So choose his forever home wisely.
The Flux S is a smart direct-drive home trainer, which means you remove your rear wheel and mount the frame directly to the unit via the dropouts. Thanks to the quick-release spindle and the supplied thru-axle adapter tips, the unit is compatible with almost any road or mountain bike, including those with Boost rear spacing.
A small problem that I encountered almost immediately was that when I installed my road bike circa 2017 with post-mount disc brakes, I discovered that there was actually about 1mm of overlap between the post-mount adapter and trainer. I was able to work around this as it’s only a slight overlap, but it’s worth keeping in mind if you’re using an older bike.
With your bike set up, you’re pretty much good to go. Getting started is as easy as plugging it in and pedaling. As you would expect from any smart trainer these days, the Flux S uses ANT + and Bluetooth to connect to various devices, and I have found it to be extremely quick and easy to connect with. my Garmin Venu, Garmin Edge 830 and Zwift on my laptop – my cheapest Zwift configuration. Part of the Garmin family, the Tacx Flux S (and all of Tacx’s smart trainers, for that matter) seamlessly connects to the rest of the Garmin ecosystem. Once all these devices were plugged in, I added a Garmin Rally power meter to test the accuracy, and I was good to go.
The Tacx Flux S is incredibly stable, thanks to its large footprint and heavy weight. It felt planted no matter how hard I worked out of the saddle, and those diagonally flared legs do a great job of preventing side-to-side movement.
Despite being the brand’s most affordable direct-drive smart home trainer, the Flux S has clearly benefited from the trickle-down technology of its higher-end siblings. As I mentioned, it was easy to log into Zwift, as well as the Tacx Training app, and from there hardly any time had passed until I pedaled on automatically changing slopes that realistically reproduced the hilly terrain of the real world.
The Flux S uses eight permanent ferrite magnets and eight electromagnets to provide resistance, and it feels great. As the resistance increases and decreases throughout the journey, there are no sudden and awkward movements; the transition is smooth and barely noticeable until the gradient really goes up or down. This is especially noticeable when climbing in Zwift.
Speaking of climbing, the Flux S can simulate slopes of up to 10%. Compared to the 25% of the Neo 2T’s capacity, this may seem disappointing to some, but when you consider that Zwift’s Mount Ven-Top has an average gradient of 7.4% and the Zwift ‘Road Alpe to Sky ”is on average. at 8.5% you can see that 10 is enough for most people.
Its maximum resistance of 1500 watts was also sufficient for my level of fitness. Of course, many “cave of pain” enthusiasts can achieve higher numbers, but only track sprinters will benefit from a trainer who can continually increase resistance beyond that point. In this case, Flux 2 may be more sufficient, as it provides up to 2000 watts of resistance and can simulate gradients of up to 16%.
As I mentioned earlier, I paired the trainer with Garmin Rally RK200 pedals to compare power readings, and while I save you the trouble of bothering you with power comparison charts, I’m sure Tacx effectively delivers on its promise to provide precision within – / + three percent. Sure, more expensive trainers will offer increased accuracy up to one percent, but for the average person, that’s more than enough to track your progress, provide consistent and reliable training, and get the most out of Zwift, or even any other virtual training. Platform.
For cadence data, the Flux S actually has a built-in sensor that intelligently uses an algorithm based on the maximum force you apply while pedaling, which again gives incredibly accurate readings.
The only concern is how responsive the Flux S is. In order to test how quickly it reacted to changes in resistance, I used the Tacx Training app to manually adjust the virtual gradient and measured how fast I felt this change through the pedals. There was a slight lag of about three seconds, which in itself isn’t a big deal, but it could make all the difference if you’re in a virtual race against people riding more premium trainers, and therefore more responsive.
The ride feel is great for what is essentially an economical direct drive smart trainer. At 7kg, the flywheel is heavier than those of the Flux S’s competitors – 1.5kg more than the Wahoo Kickr Core, 2.8kg more than the Elito Direto X – which translates to a superb, realistic driving feel that isn’t much different from what you would get on a trainer that costs twice as much.
It’s not as loud as I expected either, so it’s safe to say you shouldn’t disturb anyone else while you are working out, and if you’re like me you will be able to enjoy the casual episode of Gilmore Girls while sweating.
If you’re in the market for a smart, direct-drive trainer, you may want to consider spending at least a four-figure sum if you’re not careful, and while this may be the right choice for some, for many it is. may be overkill. The Tacx Flux S is a strong and stable indoor trainer, versatile enough to be compatible with a wide range of types of bikes using different axle and freehub body standards, and it offers excellent performance for a really competitive price.
It benefits from the trickle-down technology of the brand’s more expensive models and offers plenty of interactive features thanks to its seamless connectivity with all the favorite virtual workout apps. Plus, the driving feel is really impressive for the price.
Of course, we can’t fully forgive it for being so bulky and heavy, with no storage capacity and no carrying handle, so it’s not ideal if you need something portable for a small apartment or use. race. However, if you just want a dedicated space in your home for indoor training, then you will be a winner here. Forget about sharing this part of the house with your family though, as Flux S lives there now, will likely die there, and reign for a long time.
Technical specifications: Tacx Flux S
- Price: £ 549 / $ 749.99 / AU $ 999
- Weight: 20.9kg
- Flying weight: 7kg
- maximum energy: 1500w
- Maximum simulated score: ten%
- Max torque: 22.1Nm
- Maximum braking force: 65Nm
- Precision: +/- 3%
- Connectivity: ANT +, ANT + FE-C and Bluetooth
- freewheel: Shimano / SRAM: 8-11 speed
- Axle compatibility: QR, 12×142, 12×148
- Dimensions: 67cm x 64cm x 46cm