Popular units tested on Zwift and against pairs of power meters
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Training indoors used to have a fearsome reputation for being excruciatingly boring. The idea of spending your time on an indoor trainer, self-flagellating yourself to heavy music while you stared numbingly at a wall, all in pursuit of some intangible fitness gains over the winter, seemed like a kind of madness. Frankly, it probably was madness.
However, thanks to the advent of smart trainers and third-party interactive apps, training indoors has never been easier or, crucially, more fun.
If you’re looking at the long winter ahead and recoiling at the idea of riding in the cold, wind and rain, now is the time to invest in your indoor training setup.
Smart trainers are interactive turbo trainers that connect with apps such as Zwift, TrainerRoad and The Sufferfest to control the trainer’s resistance and replicate the hills, headwinds and drafting effects inside virtual worlds.
These apps can also guide your through power-based interval workouts with the resistance automatically adjusting to keep you at the required power (known as ERG mode).
Smart trainers work by communicating with third-party apps on smartphones, tablets and computers using wireless ANT+ frequencies or Bluetooth.
It sounds complicated, but most of these trainers and apps will automatically search for and connect to each other, so in practice it’s usually very simple.
Wheel-on or direct drive?
There are two main types of smart trainer: wheel-on and direct drive.
Wheel-on smart trainers function like classic, ‘dumb’ trainers – you clamp the rear axle into a support while your rear wheel rests on a roller drum. This drum is connected to a resistance unit that communicates with your chosen hardware and app to control the resistance you feel through the wheel.
These are typically the cheapest and lightest types of smart trainers, but they can cause wear on your tyres (though specific trainer tyres are available to mitigate this issue), their power measurement is generally less accurate, and the ride feel often isn’t as good as direct-drive trainers.
Direct drive trainers require you to remove the rear wheel and connect your bike to the trainer via a standard cassette. These are heavier and more expensive than wheel-on trainers, but prices are getting more competitive and they have a number of advantages.
Outside of the obvious one, a lack of wear on your lovely rear tyre, they also tend to be quieter and offer a more realistic, road-like ride feel. They are also usually much more feature-rich and accurate, in terms of power measurement, than wheel-on trainers.
Of course, price is always going to be a major consideration. We’ve tested a range of options to suit as many budgets as possible, but there’s no denying these trainers aren’t cheap. However, compared to a groupset upgrade or even a new winter bike, they can offer good value if you want to be able to consistently and enjoyably train indoors.
Why should I train indoors rather than just ride outside?
This is a fair question, and one that really has a very personal answer.
However, most of us will probably admit that we don’t enjoy getting wet, cold and dirty. Furthermore, if you live in a particularly busy part of the world, training indoors can be much safer – if you’re doing hard intervals to exhaustion or training in a time-trial position out on the open roads, you really need to be careful of traffic.
Training indoors can save you from all of that, and in a more positive light, training indoors can be extremely time efficient. Virtual worlds such as Zwift are also so popular now that there are organised online group rides and races – there are even national championships and the UCI is organising an esports world championships for 2020 – so you can indulge your competitive urges to make it more fun.
4.5 out of 5 star rating
Elite Suito smart turbo trainer.Simon Bromley/Immediate Media
Type: Direct drive
Maximum power: 1,900 watts
Maximum simulated gradient: 15%
Cassette included: Yes
RRP: £649.99 / $799 / €669 / AU$999
The Suito is Elite’s new, more competitively priced direct-drive smart trainer. It comes ready to use straight out of the box, so there’s minimal fuss involved in setting it up and getting riding. It’s a great plug-and-play solution.
It comes with an 11-speed Shimano 105 cassette installed, and there are adaptors for 142mm thru-axles and a front wheel riser block included in the box, all of which is especially noteworthy at this price point.
Ride quality is very good, especially considering it doesn’t have the largest flywheel out there, and we were impressed by its stability when really cranking things up.
It can simulate gradients of up to 15 per cent and has a maximum power of 1,900 watts, so really strong riders might find this unit a little under-specced, but for most people this will be more than they’ll ever need.
The H3 sits at the top of Saris’s smart trainer range and builds on the popular H2. Reducing the noise levels was one of Saris’s top priorities and it’s certainly achieved good things with the H3 – at just 61dB at 20mph (measured on an iPhone app), it’s very quiet indeed.
Ride feel is good, with the stout 9kg flywheel contributing to a very realistic experience. At 21.3kg, it’s also a very solid platform, and while this does make it quite hard to move around, Saris has at least included a handle in the design, which makes things considerably easier.
The H3 is capable of 2,000 watts of power and 20 per cent gradients. Power figures were within the claimed +/- 2 per cent accuracy, which should be more than enough for most riders. At £849.99 it’s also competitively priced, so there’s a lot to like.
Tacx Neo 2T smart turbo trainer.Simon Bromley/Immediate Media
Type: Direct drive
Maximum power: 2,200 watts
Maximum simulated gradient: 25%
Flywheel weight: Virtual
Cassette included: No
RRP: £1,199.99 / $1,399.99 / AU$1,899.99
The Neo 2T is Tacx’s top of the range smart trainer, and it’s priced accordingly. It looks like a spaceship and its spec and performance are pretty futuristic.
The Neo 2T uses an arrangement of magnets to create a virtual flywheel, and this offers fantastic ride feel, along with the ability to change the level of inertia depending on the virtual terrain. Tacx also claims the Neo 2T power measurement is accurate to +/- 1 per cent, which is up there with the best.
At this price, it’s a little disappointing that a cassette isn’t included, but that’s only a minor nitpick. Overall, the Neo 2T is about as good as it gets in terms of performance.
When you consider that it can be used without a power source (making it useful for pre-race warm ups), and that it’s also one of the quietest trainers available, you have a very compelling package. The only real problem is whether you can afford it or not.
The Kickr is Wahoo’s top of the range model. It offers fantastic ride feel, thanks to its relatively large 7.25kg flywheel, and it’s also wonderfully quiet.
Setting the unit up is very easy, with Wahoo including a cassette and a generously sized power cable, so you shouldn’t need extension leads. Once the bike’s installed, it offers a very solid platform for sprints up to 2,200 watts and gradients up to 20 per cent – these aren’t the highest maximums, but they should be plenty for almost everyone.
Power accuracy, at a claimed +/- 2 per cent, was also very good, tracking closely with our Garmin Vectors.
The Kickr doesn’t have any crazy headline features or specs, and it doesn’t come cheap, but it does everything brilliantly and without fuss. Our tester called it “the gold standard of smart trainers”.
BKool Smart Air Lite turbo trainer.Simon Bromley/Immediate Media
Type: Direct drive
Maximum power: 2,000 watts
Maximum simulated gradient: 20%
Cassette included: No
With maximum power and gradient figures of 2,000 watts and 20 per cent, the BKool Smart Air Lite offers a top-end spec, despite being the more affordable trainer in BKool’s Smart Air range.
The design is unusual – it’s meant to look like half a wheel once your bike is installed – and at 23kg and 56cm tall, with no handle, it’s quite awkward to move around. It does fold up narrowly though, so storing it away is easier.
Set up is pain-free. You’ll have to source your own cassette, but once that’s installed it’s essentially a plug-and-play unit.
The design also lends a degree of natural movement from the trainer, especially when riding out of the saddle – this divided opinion among our testers, with some finding it a bit disconcerting and others praising it for lending a more realistic feel.
The headline specs of the Elite Drivo II, Elite’s top of the range smart trainer, make for some interesting reading. Not only is it capable of simulating gradients up to 24 per cent, but it can handle a staggering 3,600 watts maximum power at 60kph at a claimed accuracy of +/- 0.5 percent!
Fortunately, it’s a bukly, stable platform, so if you’re the type of rider that can get anywhere near those numbers, you won’t have any issues, but we do have to question if any such riders actually exist in the real world.
In use, the Drivo II is great. The ride feel is impressive and it reacts very quickly to changes in incline, thanks to an electromagnet on the 6kg flywheel.
Though its bulk comes in useful when laying down the power, it’s a bit of a hindrance when it comes to storing the unit. Furthermore, it faces stiff competition in this price bracket and though it’s able to offer accuracy and maximum power figures wildly beyond anything else, it’s not clear exactly who would benefit from that extra headroom.
The Kurt Kinetic R1’s unique selling point is the ‘rock and roll’ design, which allows a significant range of side-to-side motion. At first, the range of movement can be disconcerting, especially if you’re used to a rock solid trainer such as the Wahoo Kickr, but once you get used to it it feels more natural.
Beyond that headline feature, the Kinetic R1 has great ride feel thanks to its 6.3kg flywheel and wide-legged stance. The resistance changes smoothly to match changes in the virtual terrain, and with a 2,000 watts and 20 per cent gradient ceiling it ought to satisfy most people’s requirements.
It’s not the quietest trainer at 75dB, but it’s not noticeably loud either. Ultimately, whether this is the right trainer for you will depend on how you feel about the rock and roll design – if you want that unique ride feel, the Kinetic R1 is a great unit.
The Saris M2 is a relatively affordable, wheel-on smart trainer. Using a classic A-frame design, it only weighs 9kg, making it easy to move around, and it folds up neatly for easy storage.
For a wheel-on trainer, the Saris M2 is noticeably quiet. It can’t quite compete with the better direct-drive trainers, but it’s not far off (tyre choice will affect this however).
Ride feel is good, if not spectacular – largely due to the fact that it only has a 1.2kg flywheel, meaning it struggles to compete against more expensive units – and we also found the power accuracy to be better than the claimed +/- 5 per cent, once properly calibrated.
If you’re looking for a direct-drive smart trainer, but can’t quite stomach the prices of some of the high-end models, the Tacx Flux S might be the one you’ve been looking for.
It’s easy enough to set up, simply requiring you to attach the legs to the resistance unit with the supplied Allen key. There’s no cassette in the box though, so you’ll have to get one of those before you can start riding.
With its 6.7kg flywheel it has good ride feel, but there is a ceiling of 1,500 watts power and just 10 per cent simulated gradients, which might occasionally be limiting for stronger riders in comparison to other trainers.
The only other niggle is that the trainer doesn’t fold up for easy storage – the legs are simply fixed in place with bolts. This won’t be a problem if you have a dedicated pain cave, but if you need to be able to easily stow it away, this might be a dealbreaker.
When testing these units, we first considered the price of each trainer and what is included in the box — adding on things such as cassettes, spacers or adaptors can add a premium and are worth factoring in.
We then considered how easy it was to set-up the trainer, and how easily it paired with Zwift.
Next, we tested the ride quality on Zwift to see what the trainer felt like at a constant power, as well as when accelerating, climbing and sprinting out of the saddle. This looked at both the physical stability and how the trainer reacted to Zwift, including changes in terrain and changes in power. These power results were compared with Garmin Vectors.
A flywheel helps to create a road-like feel due to the kinetic energy they’re able to store, and the resultant inertia they give – essentially, when you stop pedalling it should feel like you are coasting on a real road.
It’s generally considered that the heavier the flywheel, the better the ride feel ought to be, but this isn’t always the case. Construction, materials and design all play a role, and some brands are in fact now using virtual flywheels with magnets.
Though more expensive, virtual flywheels have the advantage of being able to change the level of inertia depending on the virtual terrain – so climbing should feel different to riding on the flat, just like in the real world.
Weight and packability
Trainers come in a wide variety of shapes, sizes and weights. Wheel-on trainers are, more often than not, the lightest and most packable kind of trainer. Direct drive trainers tend to be much, much bulkier. Though size and shape can vary wildly – with some models folding up to a very slim form – they tend to all be pretty heavy regardless.
If you’ve got a dedicated pain cave, it may not matter at all how big and heavy your trainer is. But if you have to set it up and then pack it down before and after every session, then you’ll need to take this into consideration, especially if you have cyclists’ arms.
Power and gradient
Trainers have different maximum power figures that correspond to the amount of resistance they’re able to generate. They range from 1,500 watts to over 3,500 watts, but 1,500 watts should be plenty for most people, and 2,000 watt models ought to be enough for practically everyone except professional sprinters.
The gradient figures relate to the maximum incline a trainer can simulate – given in per cent, like on the road. Again, a lower figure isn’t going to hinder your training, it simply means those trainers won’t be able to simulate the virtual world perfectly whenever the gradients go beyond what the trainer is capable of.
Trainers used to be notoriously noisy, but there have been vast improvements made over the past few years. On-wheel trainers are still typically louder than direct-drive trainers, but the gap has narrowed considerably.
The quietest trainers are direct-drive though, with some models being so quiet that the sound from your drivetrain becomes the main source of noise.
If you want to be able to train inside your house or flat early in the morning, perhaps before your partner/family/housemates wake up, or after work when they’re trying to watch their favourite series in the next room, a quiet trainer is a must.
First of all, most smart trainers need to be plugged in to the mains electricity supply in order to function properly. A good quality extension lead might therefore be necessary, depending on where you’re going to set up the trainer because the supplied plugs don’t always have super-long wires.
We recommend using Bluetooth to connect all of your hardware together, but if you have ANT+ accessories (such as an older power meter or a heart rate monitor) that you also want to connect, then you’ll need an ANT+ dongle for your laptop or tablet.
You might need a riser block for your front wheel. Whether you do or not depends on each model of trainer, but it’s worth checking because those that need one to level you out don’t always come with one included.
They’re not essential, and you could theoretically use a yellow pages (if those still exist) or a bit of 2×4 to level things out, but a dedicated riser block will work better and they’re not that expensive (unless you want it to be, in which case Wahoo will sell you its Kickr Climb gradient simulator).
A trainer mat of some sort – preferably one that’s rubberised – will help catch your sweat and will also help dampen vibrations and keep noise levels down, especially if you’re using your trainer on a wooden floor (which tends to amplify the sounds).
Sweat nets that cover your top tube, steerer tube and stem might also be a good investment to protect them from sweat and corrosion, but what you really want is a big, powerful fan. Something around 20 inches will do, or if you’re really flash you can get a ‘smart’ fan such as the Wahoo Kickr Headwind.
If you’re using a laptop or a tablet then a specific stand to hold it in front of you is very useful as well, or if you want to use a TV, then the Apple TV box is able to use the Zwift app.
Simon is a freelance writer and photographer, who has been riding bikes for fun since he was a kid, but took a deep dive into road racing, crits and time trialling culture whilst living in London in his twenties. As a man of very little talent, he always looks to tech to compensate and loves nothing more than finding a smart (preferably cheap) hack that others hadn’t thought of. His stable of bikes certainly isn’t the most extravagant, but they’re all customised to meet Simon’s particular tastes and kept fastidiously clean. His current No.1 bike is a 2009 Giant TCR Advanced SL, that he purchased second hand from a friend in London — he maintains that the 2019 TCR is basically the same bike, so why bother upgrading?