Indoor Trainers 3: Direct Drive Turbo Trainers

Now that we’ve covered Rollers and Tyre-Drive Trainers, it’s time to take a look at Direct Drive Turbo Trainers. Rollers are great for cadence work, and they offer a simple, durable solution to indoor training for minimal expense. Tyre-drive trainers add some extra resistance to add some variety to your training. If you’re planning to spend a lot of time on an indoor trainer, you should probably consider a Direct Drive trainer to get the most out of the experience.

How do they work?

Direct Drive turbo trainers fit to your bike in place of the rear wheel. Your chain drives a cassette which is fitted onto a freehub, much like a normal bike wheel. This freehub drives a big flywheel, with electronically controlled resistance (usually). The flywheel allows you to freewheel for slightly longer periods than you can on a tyre-drive trainer without losing all momentum – very similar to if you’re out on the road – and some more premium models have the ability to power the flywheel to simulate the feel of pedalling on descents. Resistance is usually created by magnets, either by moving a large magnet closer to the flywheel, or by changing the power supply to an electromagnet. Most smart interactive trainers feature power meters, some can also monitor your pedalling cadence.

Direct Drive trainers can be used without a power supply, but you won’t get all of the features; most just offer a limited amount of resistance sufficient for a pre-event warm up, and may not transmit any data. For indoor use, Direct Drive trainers are usually the quietest option, so that’s worth considering if you’ll be training regularly at unsocial hours. They also make it very simple to alternate between riding on the trainer and using the bike outside, as you don’t have to fit a turbo tyre like you would with a tyre-drive trainer. We’ll cover cassette and freehub compatibility in detail in part 4 of this series, but most riders will fit a second cassette to their indoor trainer, allowing them to quickly swap in their back wheel if they want to use their bike out on the road.

Bike compatibility is something you should check on a case-by-case basis, as some older trainers were designed primarily around quick-release bikes. However, most Direct Drive trainers since around 2020 have featured a design which works well for both QR and Thru Axle bikes. Trainers are generally supplied with axle adaptors to work with 130 and 135mm QR, 142 x 12mm thru axle, and 148 x 12m thru axle, covering most modern road, gravel/CX, hybrid and leisure bikes. Many brands offer additional adaptors for more unusual axle standards such as 141mm QR or 135 x 10mm thru axle, but it’s best to check what’s available for each specific trainer before purchasing.

Most brands also offer different freehub options to suit the different drivetrain manufacturers, but again it’s best to check availability for each specific trainer. Sometimes trainers are supplied with a common cassette size, which may not be suitable for your bike, other times they come with a bare freehub to fit your own cassette. If you’re not sure what you need, this will also be covered in part 4. While it’s very quick and easy to get a single bike on and off the trainer, alternating between multiple different bikes can be a bit more tricky, unless you can find a common compromise that works with multiple bikes. Say you have a road bike with 12-speed SRAM gears and thru axles, and your partner has a bike with Campagnolo 11-speed gears and quick release wheels, you would need to change the freehub and end caps each time you wanted to use the trainer. While changing a trainer freehub isn’t usually a particularly arduous process (usually just unscrew the end cap and it slides off), it would quickly become tiresome if you’re both planning to train several times a week. In this instance, consider looking at something like the Elite Square, or a smart bike such as the Tacx Neo Bike instead.

One solution to the drivetrain compatibility conundrum is the Zwift Cog, something you’ll see shipped with several newer trainers. This is a singlespeed sprocket which should work with almost any drivetrain, and uses software to provide adjustable gear ratios.

Direct Drive trainers tend to be quite sturdy and stable, although some models are designed specifically to be smaller and compact, like the old Elite Suito. They generally have a broad, stable base, sometimes with adjustable feet to level the trainer on uneven floors. It’s worth investing in a trainer mat if you’ll be training indoors, to reduce noise and help absorb vibrations. The trainers are stable enough to ride out of the saddle, but try to keep your bike and body in-line, like a track sprinter – waving your bike side-to-side like Thomas Voeckler will cause a lot of stress on the dropouts of your bike and may lead to premature frame failure. If you’re spending a lot of time on the trainer, consider one which has some kind of mechanism to absorb rider movement. Some newer model Tacx Neo trainers feature “motion plates” which let the trainer rock back and forth slightly under your pedalling input, reducing rider fatigue and load on your backside. Elite have a similar feature called “flex feet”, using small elastomers. If you’re really going to put some miles in, these features will make a difference to your comfort.

Smart vs Smart Interactive

This is quite an important distinction to clear up if you’re looking at older trainers or the second hand market, or if you’re considering upgrading from an old trainer. Most trainers marketed as Smart these days are actually Smart Interactive. In short, a Smart trainer will keep track of what you’re doing, and transmit this information to a bike computer, or to training software such as Zwift. However, this information flow is one-way – the trainer can’t receive any instructions, so you still have to manually control the trainer yourself. This will enable you to ride around a virtual world, or record your training sessions more precisely, but you won’t exactly get the full experience and relatively natural riding experience of a modern Smart Interactive trainer.

While we’re here, it’s worth making a quick mention of Fluid Trainers, such as the old Elite Turno and Volano units: these use a spinning turbine moving through oil to generate resistance - a bit like the torque converter in an automatic car transmission. Fluid trainers quite simply increase the resistance the faster you go, no software required: the harder you go, the harder it gets. You don’t see these trainers that often any more, but they’re a great, simple training tool that can handle a lot more power and torque than a tyre-drive trainer. Fluid trainers are generally Smart trainers, so they’ll transmit your riding data, but they won’t work well with platforms like Zwift, particularly if you’re riding with others.

That brings us to Smart Interactive trainers. These not only send information, but can also receive instructions from training software, allowing you to make the most of virtual training platforms like Zwift, Rouvy or MyWhoosh, or simply follow a saved course from your bike computer. The trainer can simulate gradients (up to anywhere between 10 and 25% depending on the trainer), and cope with significant power outputs, usually well above 1000 Watts, again depending on the trainer. The trainer will automatically adjust the resistance as required, allowing you to just enjoy the ride and focus on your training.

Pros:

Engaging experience

Quiet

Stable

Capable of Intense Efforts and High Power Output

No need to fiddle with trainer tyres

Cons:

Fiddly to swap between multiple bikes with different drivetrains

Expensive

Requires power supply to use to full capacity

Cassette and freehub compatibility

Our Recommendations:

Best Entry Level Trainer: Elite Rivo

At this price point, the Elite Rivo is hard to beat. The trainer is compact and folds away easily for storage. It can simulate up to 18% gradients, and handle a maximum of 2000 W at 2.5% accuracy. It’s supplied with a Zwift Cog for easy drivetrain compatibility, but also works with all of the common freehub and cassette standards. Combine that with environmentally conscious Italian manufacturing and long-term spare parts support, and you’ve got yourself a great value trainer which will work reliably for years to come. If you’re just a leisure cyclist, there’s probably no great benefit to spending more than this.

Best Overall Value: Elite Avanti

If you’re planning some more intense training, the Elite Avanti is a nice step up. It has the same sturdy construction as their top-of-the-range Justo unit, just without quite so many of the fancy features. Flex Feet help reduce fatigue and noise. Again, it can simulate up to 18% gradients and handle a maximum power of 2000 W, but accuracy is improved to 1%. It features WiFi connectivity for a faster connection, as well as dual channel bluetooth “bridge” functionality, allowing you to pair your additional sensors straight to the trainer – this is particularly handy if you’re running your training software on an Apple TV, which can only handle 2 simultaneous bluetooth connections.

The Fancy One: Tacx Neo 3M

Do you want a smart, stylish trainer with top-of-the-range features, look no further. The Tacx Neo 3M can simulate up to 25% gradients, and handles up to 2200 W output, with 1% accuracy. Motion Plates are built in for comfort, and the trainer is notably quiet in use, for the comfort of your family and neighbours. If indoor training isn’t uncomfortable enough for you already, there’s an optional “road feel” feature, which uses a small flywheel to create vibrations to replicate real-world riding conditions – now you can enjoy riding across the cobblestones of Roubaix in your own living room. The optional Smart Network Adaptor provides faster connection to e-sports platforms for improved accuracy and speed. Unlike Elite’s repair-friendly philosophy, Tacx trainers are factory sealed units, offering great reliability and accuracy for a long time, at the expense of repairability if something does go wrong.

Best No-Frills Performance: Elite Justo 2

If you’re thinking of some e-sports racing, or just enjoy making yourself suffer, then have a look at the Elite Justo 2, which builds on the functionality of the Avanti. Collapsible legs make this trainer quite easy to store compared with some of its competitors at this level. It can simulate up to 24% gradients and handle up to 2200 W, with an accuracy of less than 1%. RACE mode increases the frequency of readings and transmission, offering improved accuracy and response. Flex Feet help absorb rider movement and reduce vibration, and there’s a 12-speed Shimano cassette pre-installed. Elite’s Italian manufacturing ensures good spare parts support, so while it’s a big up-front cost, the Justo 2 should be a good investment.