Smart trainers allow third-party apps such as Zwift, TrainerRoad and The Sufferfest to take control of the resistance to replicate hills, headwinds and drafts inside groups, and also guide you through power-based interval workouts.
I tested 10 of the best smart trainers on the market right now — including models from Wahoo, Tacx, Elite, CycleOps and Kinetic — on Zwift and against pairs of power meters.
Why a smart trainer?
So what is a smart trainer, you ask? ‘Smart’ here means two-way communication on speed, power and cadence with apps on your phone, tablet or computer.
It also means apps can control the trainer’s resistance. So, when you come to a virtual hill or the start of a work interval, the trainer automatically makes it harder to pedal. Similarly, when riding in virtual groups, it adjusts for a draft: ride behind a big group and it’s easier. Go to the front and it gets harder.
Smart trainers work on cycling’s standard wireless ANT+ frequency and Bluetooth, which is native for many modern smartphones and laptops.
To use a smart trainer, you need your bike, a computer, phone or tablet and WiFi. If you are using a computer without Bluetooth, you’ll also need an ANT+ USB dongle.
There are two types of smart trainers.
Wheel-on smart trainers are less expensive, and look and operate similarly to a traditional trainer where you clamp your complete bike in at the rear axle.
Direct-drive trainers require that you remove your rear wheel, install a cassette on the trainer, and then mount your bike on the trainer.
Best wheel-on smart trainers
Wheel-on smart trainers are your least expensive options. The major cons are the warm-up time needed to calibrate, and the fact that power measurement accuracy generally isn’t as good as direct-drive.
But, they are pretty easy to use, and don’t require an additional cassette. Although heavy, they are lighter than direct-drive trainers and most of them fold up for storage or transport. And all of them give you an interactive experience.
Wahoo Kickr Snap
- £499 / $599 / AU/€ pricing unavailable
- Pros: Steady feel, reliable power when calibrated
- Cons: Sluggish to recognize accelerations as power is measured behind flywheel
- Feel: Steady, secure
- Power accuracy: Very good, at <2% to meters’ average
- Stability: Solid design, height-adjustable feet
- Noise: 70dB at 200w/80rpm; 81dB max
- Portability: Relatively easy with folding legs
The Wahoo Snap is an excellent wheel-on trainer. Set up is easy right out of the box with fold-out legs and intuitive handles for the rear axle and tire roller.
As with any wheel-on trainer, once you have adequate resistance, you can just hop on and start riding, but you’ll want to calibrate for better power accuracy. This means doing a 10-minute spin to warm up the tire, then doing a quick spindown calibration.
The Snap is nice because you can do the spindown with the Wahoo app, or even right inside Zwift.
Testing against Pioneer and Garmin Vector 3 power meters simultaneously, I found the power measurement to be very good, at less than a two percent variation for average power.
As with most wheel-on designs, there is a slight lag in the power reading for initial hard accelerations, as the power is measured behind the flywheel. This can be a little frustrating in virtual races, but on the upside, that measured power continues for the same total duration as you applied it, there is just a bit of a lag.
Speaking of the flywheel, the 10.5lb / 4.8kg weight adds to the great road feel of the trainer.
Your tire won’t slip on the drum, and the steady adjustable tripod design won’t rock on the floor. Some users have found their Kickr to vibrate at high speed, but I haven’t experienced that.
The Wahoo Snap is the quietest wheel-on smart trainer I’ve tested, both at steady power and at max output.
- £399 / $549 / AU/€ pricing unavailable
- Pros: Instant change in gradient resistance, steady feel, easy to set up, price — especially in the UK
- Cons: 2–3s delay in acceleration power, noisy, power reads high
- Feel: Good
- Power accuracy: Consistent, but 12% high compared to meters’ average
- Stability: Good
- Noise: 73dB at 200w/80rpm; 90dB max
- Portability: Relatively easy with folding legs
The Tacx Vortex is also easy to set up, with a steady feel and instant changes in virtual gradient resistance.
I found the power readings to be consistent, but also 12 percent high compared to the averages of the Pioneer and Vector 3 meters.
For all power testing, I calibrated each of the meters and the smart trainers before each test.
As with the Snap, the Vortex has a slight delay in accelerations, but you’re not being robbed of measurement, just slightly deferred.
The price, especially in the UK, is good for a smart trainer.
I also tested the Elite Qubo Digital Smart B+, Elite Arion Digital Smart B+ rollers and Kinetic Rock and Roll Smart Control. These didn't make the best list but are still worth considering, and you can read the full reviews via the links below.
Best direct-drive smart trainers
By removing your rear wheel and tire from the equation you also remove some of the hassle and inaccuracy of the wheel-on model. If you are taking your bike off and on, you don’t need to do a long warm-up before calibrating, you just get on and go, with good data all the while.
Within the direct-drive category, spending more money means less noise, slightly better power accuracy, and conveniences such as pop-out legs versus bolted legs. At the top end, the Tacx Neo has a cool surface feature to replicate things like cobbles and dirt roads as you ride virtual courses.
- £889 / $1,199 / €1,298.99 / AU$1,699
- Pros: Great calibration out of the box, solid stance, spring-loaded legs
- Cons: Price, noisier than the Wahoo Kickr and Tacx Neo
- Feel: Realistic
- Power accuracy: Excellent at 2% to power meters’ average and highly consistent
- Stability: Rock solid at the base and the axle
- Noise: 72dB at 200w/80rpm; 86dB max
- Portability: Easy pop-out legs and wheel tray
CycleOps has been making power meters longer than anybody other than SRM, so it should be no surprise that the measurement on the trainer is pretty darn good. I measured it within two percent of the Pioneer and Vector meters, with very consistent behavior.
The Hammer has legs that pop out and adjust for height, plus a little wheel tray that tucks into the feet for storage.
The Hammer has zero give at the axle, so the trainer and your bike are fully rigid. Whether this is a positive or a negative is a matter of personal preference.
The Hammer is a tiny bit louder at steady state than the others, and definitely louder for max efforts.
Maximum replicated slope is 20 percent and maximum power is 2,000 watts. Good luck with both of those!
- £999 / $1,199 / AU$/€ pricing N/A
- Pros: Early leader, software integrates well, dead level power in workout mode appealing to particular types
- Cons: Price, dead-level power might be unnatural for some
- Feel: Smooth
- Power accuracy: Excellent, at <1% to power meters’ average
- Stability: Rock solid at the base and the axle
- Noise: 71dB at 200w/80rpm; 80dB max
- Portability: Big handle, pop-out legs
While CompuTrainer was the first interactive trainer, the Wahoo Kickr was the first to offer an interactive trainer on an open platform. As such, it still has lead in how it plays well with others.
It is easy to use with all the major apps — and your phone and your Garmin and of course the Wahoo Elemnt head units.
Power-wise, the Kickr tracks along gratifyingly with power meters, and in fact can be calibrated to your power meter of choice if you so prefer.
With a heavy flywheel and an electro-magnetic brake, the feel is excellent and the trainer is quiet at all speeds.
The kicker with the Kickr is its controlled power; some will love it and some will find it weird. When doing controlled intervals, the Kickr will report that its controlled power and your actual power are eerily close, delivering bar-graph-like results in your wattage reports. On one hand this can be gratifying to see. On the other, there is no way you are actually holding power that smoothly.
But in either case, the Kickr plays well with others, delivers a quiet and buttery smooth ride, and — although heavy like the rest — is relatively easy to move thanks to the big handle and pop-out adjustable legs.
Tacx Neo Smart
- £1,249 / $1,599 / AU$1,899 / € pricing N/A
- Pros: Excellent virtual feel including boosts on downhills and varied vibrations on surfaces such as dirt, cobbles, wooden bridges, etc
- Cons: Price, no way to calibrate
- Feel: Incredible: smooth under virtual and workout modes, plus simulated road surface feel and sound
- Power accuracy: Excellent; very consistent but always a little lower than power meters
- Stability: Rock solid base, slight give at axle
- Noise: 70dB at 200w/80rpm; 80dB max
- Portability: Fold-up legs, no assembly required
Looking like a spaceship off the set of Star Wars, the Neo lights up the ground with colors coded to your level of effort.
Laser light show aside, the Neo’s real magic lies in the electro-magnetic interface. With a varied series of short stutters, the Neo can replicate the feel and, to some extent, the sound of riding over cobbles, dirt roads, loose boards and more.
The feeling is surprisingly good, as the feedback comes at the pedals.
The Neo also has a cool feature where you get a bit of a boost on downhills. If you coast while on a downhill, then start to pedal again, on most trainers you get a bit of resistance at first. With the Neo, the pedals turn as easily as they would outside.
And, of course, the Neo reacts to adjust resistance for uphills and guided power workouts.
There are only two problems with the Neo. One is cost. And two, there is no way to calibrate the thing.
Tacx claims that the system comes perfectly adjusted and requires no calibration. That may be the case, but I was frustrated to see that while the power readings were very consistent, they were also about 4–8w watts below the calibrated power meters I used for testing. I did 10 one- to two-hour rides on the Neo, testing against pairs of meters from Shimano, Stages, Garmin and Pioneer.
Tacx engineers said drivetrain efficiency losses account for the delta in power measurement at the cranks and pedals. I asked Jason Smith of Friction Facts/CeramicSpeed about this, and he said that split was reasonable, given my Dura-Ace chain with Lilly Lube.
The Neo is a delight to ride; it is quiet, responds quickly and smoothly to resistance changes for virtual undulations or power workouts, and the surface treatments make riding Zwift more engaging than any other trainer.
Tacx Flux Smart
- £699 / $899 / AU$/€ pricing N/A
- Pros: Great price for direct drive, pretty quiet at steady power
- Cons: Fixed legs, good but not excellent power readings
- Feel: Smooth and steady
- Power accuracy: Consistent but high
- Stability: Rock solid tripod
- Noise: 70dB at 200w/80rpm; 86dB max
- Portability: Bolted legs
After doing a calibration with the Tacx app, I found the Tacx Flux to measure power fairly well — within two percent of the Pioneer, Shimano and Garmin power meter averages, with relatively consistent tracking and the ability to catch quick jumps and spikes.
The legs bolt into place, so you’ll need a dedicated space for it, but the design is rock solid.
Its max power is ‘only’ 1,500 watts, but I’d like to see the rider who can top that on a fixed trainer inside. Of more relevance to Zwift riders, the gradient simulation tops out at 10 percent — the lowest of the direct-drive trainers.
- £749 / $899 / AU$/€ pricing N/A
- Pros:Great calibration out of the box, solid stance, spring-loaded legs
- Cons: Reactivting ERG causes 450w lurch (when reengaged at 180w), screw-on legs
- Feel: Good
- Power accuracy: Very good at <2% variance of power meters' average
- Stability: Rock-solid base, slight give at axle
- Noise: 71dB at 200w/80rpm; 80dB max
- Portability: Screw-on legs can pivot inwards
Going head to head with the Flux on price is the new Elite Direto, which I found to have great power measurement after doing a calibration with the Elite app. After calibration, it read within a single percent of the Pioneer and Garmin power meters for average power, and tracked consistently with them for spikes and valleys.
The legs pivot in for storage, using a big dial on each leg to loosen and tighten.
The feel is steady and smooth for both virtual riding and interval training.
My one complaint is the stutter in required power when reactivating ERG mode. ERG mode – which is when an app is controlling the resistance – gets deactivated when you can’t match the required power for a few seconds. When the software senses this, it releases the heavy resistance and lets you spin for a while. Then, once you’re going again, it will reactive the ERG mode at the preset power. After it does this, there is a short but very noticeable load of about 450 watts before it settles in at the preset power.
The Direto is quiet at steady power and under hard efforts. Max power is 1,400 watts and max gradient is 14%.
Smart trainer bottom line
So which of these is the best? Well, like any tool, that depends on your budget and intended use.
All of these trainers do a good job bringing virtual riding to life. The more money you spend, the better experience you get.
For power measurement, though, there are clearly two classes of smart trainers. The direct-drive trainers are markedly better than the wheel-on options.
If you already have a power meter, I would recommend using that for your measurement. Connect your meter to Zwift or TrainerRoad, or whatever app you are using for the power measurement, and then connect the smart trainer for the resistance control. I’d advise that even with the direct-drive trainers, just so you are seeing consistent numbers inside and outside.
The best bang for the buck has to be the new Elite Direto. It works very well at under a grand.
The CycleOps Hammer is an excellent option with a smooth road feel and a forgiving algorithm for when you stall out on ERG mode. It is rock solid and easy to use. It’s just a little louder than the other top-end trainers.
The Neo’s surface treatments engage you like no other trainer can, and its power measurement is hyper dependable. The fold-out wings are rock solid, but the hub has a bit of give, which I appreciate. You can even use it without power, although you don’t get the cool downhill assist functionality. My only hesitation is that the Neo’s power is always just a few watts below that of power meters.
I should note that the Hammer measures similarly. In both cases, you can chalk up the delta in power to drivetrain-efficiency losses. You can absolutely train with confidence to the Neo and the Hammer.
Note that the Neo isn’t compatible with long-cage derailleurs.
With the Kickr, you can’t feel the cobbles, but you do get a quiet, silky smooth, virtual experience with dependable power. Unlike the Hammer and the Neo, I found the Kickr’s reported power to nearly mirror my power meters’ data.
The Kickr is the easiest direct-drive trainer to live with, too, with a compact design that folds in quickly, a sturdy handle, and full compatibility with thru-axle bikes and all lengths of rear derailleur cages.
Article updated 12 February 2018