Zwift Hub smart trainer

The new Zwift Hub trainer is an excellent way to get into smart training. It's not just a good trainer for the money, it's a good trainer full stop. If you're not racing at a high level then it's likely to be all the trainer you need.

You might remember that Zwift announced a real-life Tron bike and then it didn't happen; we'd still like to see that, thanks. But all the while it was working on the Hub trainer behind the scenes, so it was always keen to enter the hardware side of the market.

> Buy now: Zwift Hub for £449 from Zwift

The reason for this is simple: a big proportion of the people who sign up to Zwift never go on to log a ride on the platform. This might be for a number of reasons but a big sticking point is getting set up: knowing what hardware you need, and how to get your bike attached to it.

The Hub trainer is designed to be as easy to set up as possible so that anyone with any bike can get onto the platform simply and cheaply. Relatively speaking, anyway.

Zwift Hub trainer: the specs

Zwift isn't concentrating on the numbers – the sell of the Zwift Hub is more about the simplicity of the setup and the integrated experience. But for your £449, you're getting a genuine direct-drive smart trainer with a claimed accuracy of +/-2.5%. It has a maximum resistance of 1800W and can simulate a gradient of 16%. For the money, those are very good numbers.

It's got a 4.7kg flywheel and is ANT+ FEC and Bluetooth FTMS controllable so it will work with pretty much anything you can run Zwift on.

On top of that, it can also act as a Bluetooth or ANT+ heart rate monitor bridge so that you can transmit your heart rate data via the trainer. This is really useful if you want to save a Bluetooth channel if you're running Zwift on your Apple TV, which only allows two connections.

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Because it's a Zwift product, the calibration, firmware updates and heart rate bridge functionality will all be available through the Zwift apps.

At the moment you have to do a spin-down calibration for the Hub trainer, but Zwift says it's working on making it calibration-free in a later update. At present calibration is only possible if you're connected via Bluetooth, not ANT+.

If you're a smart trainer aficionado then you might be thinking that this new Zwift Hub trainer looks a lot like JetBlack's Volt smart trainer, and you'd be right. Zwift has been working with JetBlack, and a lot of the hardware is shared.

JetBlack had some frame compatibility issues with the Volt at launch, and Zwift was really keen to make sure that the Hub fitted as many bikes as possible. To that end, it's had prototype Hub trainers with bike mechanics over the past year so that bikes coming in for service can be checked for fit.

Zwift is really confident that the Hub trainer will fit pretty much any bike that you'll throw at it: it's had it working with over 500 bikes from 70 brands and frame sizes from 45cm to 64cm.

Zwift Hub trainer: assembly

The Hub trainer comes with a cassette installed. That's not uncommon, but what is currently unique with this trainer is that at the checkout you can choose anything from an 8-speed to a 12-speed cassette. So when your trainer arrives in its box, it's basically ready to go once you bolt it together. You can even watch a video that'll show you how to check the number of sprockets on your bike, if that's the sort of technical level you're approaching indoor training from.

When your trainer lands there's a QR code on the side of the box and that takes you to a page where you can access a whole load of videos about the different aspects of the setup. So if there's anything that you don't understand, you should be able to get help.

The trainer comes in three main parts and the legs are colour-coded with the base so that you can make sure you get everything in the right place. You can follow the steps in the instructional video, and for nearly everyone it's going to be a fairly simple job.

One of the main issues with getting a bike on a trainer is axle standards, and Zwift has produced some clever axle end cards that are also colour coded. They have a ruler section you can use to check the distance between your dropouts so that you can make sure you're running the right bits, the right way round.

Again, if you're unsure of what you're doing then the instructional videos that Zwift has produced will set you right.

Is it the easiest trainer to get set up on Zwift with? It depends. If you're on an 11-speed bike and you're buying another trainer that comes with an 11-speed cassette, and doesn't need assembling – for example the Elite Suito – then that's easier: you literally just need to take it out of the box, unfold it and plug it in. But there's no doubt that Zwift has put a lot of time and effort into making things as straightforward as possible. And the fact that you can spec the correct cassette for your bike at the point of purchase means there's one less thing to worry about when it lands on your doorstep.

Also, the fact that the trainer's functionality will be baked into the Zwift environment means you're likely to have a more seamless experience.

I really like what Zwift has done with the end caps and the measuring cards too – that will make a tricky job for less technically savvy people a lot easier. There's a bit of spannering to do, but really anyone should be able to get this trainer up and running in about 15 minutes, and that won't really change much if you're on a 12-speed, thru-axle, disc brake gravel bike or an old 9-speed racer.

We've already put plenty of miles into the Zwift Hub trainer; in fact we've had two, a pre-production one and a final version. In terms of ride feel, the trainer is really good. At £449 you're getting a really capable direct-drive smart trainer with a comparable feel to units that in many cases cost quite a bit more.

The trainer is quick to react to changes in gradient, and the flywheel is heavy enough to keep your pedal action smooth as the resistance alters over the terrain. It's a very quiet trainer, too.

Zwift Hub trainer: power and accuracy

So let's move on to power and accuracy. I know Zwift isn't making a big thing about this for the launch, but with any smart trainer you want to be sure that the numbers that are appearing are at the very least repeatable, and preferably as accurate as possible. Let's work through some graphs, starting with this one.

This is my power trace from a Zwift race around the New York park perimeter course. The purple line is the Zwift Hub and the blue line is my Rotor 2InPower cranks, which I've used to benchmark any number of trainers and always found to be accurate. As you can see, the two lines mirror each other very closely, and there's only a couple of watts of difference between the average power recorded on the Zwift Hub and the cranks.

If we look at the mean power curve for this race that's borne out across the board. You can see that there's a slight discrepancy at the higher end with the Zwift Hub trainer slightly under reporting compared with the Rotor cranks, but it's an insignificant difference, and most likely can be attributed to the fact that the power numbers on the trainer rise more slowly than they do on the cranks, where an increase in power is reported more or less instantaneously.

Further down the curve, the two lines are more or less indistinguishable, and that suggests that the Zwift Hub is doing an excellent job of reporting power all the way across the power spectrum.

A trainer doesn't have to be far out to be noticeable, if you know what your numbers are. The Zwift Hub feels just about spot on for me. I've done quite a few races, and it very much panned out as expected. That is, not especially well.

If you're into racing then the Hub trainer is certainly capable of dealing with the cut and thrust of a bunch sprint; it's not especially heavy, but it feels very stable when you're out of the saddle. More powerful riders might find that the maximum resistance is a little underwhelming, and a touch laggy in a dash for the line – it builds a bit slowly, and lacks the immediacy of a more expensive smart trainer, or numbers from an on-bike power meter. But overall it's a very competent trainer.

Now let's look at another power graph. This one is from a power benchmarking workout in ERG mode that I like to use to test the response of trainers at a number of different power levels. The colours are reversed here – the Zwift Hub is blue and the Rotor cranks are purple. ERG mode works very well. The hub trainer reacts well to the interval changes and ramps up power quickly, but not too quickly; it's about right. Holding a steady power was no trouble at all.

Again, the average powers are very similar. There's about 3.5W in it this time. The fact that the Zwift Hub under-reports slightly compared with the Rotor cranks at higher power is obvious from the final two intervals. The gap was more pronounced in this test but that's probably down to there being not much data at the top end.

The other thing that is obvious is that the Zwift Hub trainer is doing quite a lot of smoothing on the ERG graph. It reminds me a lot of the Wahoo Kickr trainer which has an ERG smoothing option that you can turn on or off. Here there is no option: you just get the doctored line. And it is doctored. You can see that in the third to last interval, where I'm winding up the trainer to do the interval at a higher cadence, my power spikes on the Rotor crank graph but stays level on the Zwift Hub line. What's basically happening there is that the Rotor cranks are reporting the power that I'm actually putting out, and the Zwift Hub is pretending that I'm keeping things steady when I'm not.

It's not a deal breaker. Overall, the Zwift Hub makes a really good job of holding power at the right level during an ERG interval. I'm not sure why Zwift has decided the ERG line needs this makeover – looking at the actual power reported from the cranks I'd say it's generally very good indeed, better than some trainers I've tried at twice the price. You can see at the start of intervals that the trainer sometimes slightly overestimates the resistance it needs and backs off, but that's very common and it's no worse here than it is on some much more expensive trainers. Once it's on power, it holds it really well.

Let's move on to the cadence graph. Obviously, the Rotor cranks can tell that they're physically being rotated, while the Zwift Hub uses an algorithm to detect cadence by looking for differences in the power output around the pedal stroke.

We can say with a degree of certainty that the Rotor cranks are going to be accurate here, so when there's a difference it means that the Zwift Hub's algorithm isn't quite getting things right.

Most of the time it does a good job. The one area where it seems to struggle is when you're moving from a high cadence to a low cadence or vice versa. Where there's a big spike in cadence up to about 120rpm, the Zwift Hub thought I was doing half that before changing its mind halfway through the interval. And at other points where my cadence changed it takes the Zwift Hub a little while to nail down what's happened.

It's not as good as more expensive trainers that use passive sensors to detect foot movement, and it's obviously not as good as a crank-based solution, so if you wanted accuracy here you could just add a Bluetooth cadence sensor. But for the most part it's absolutely fine.

Zwift Hub trainer: value

On the value side of things, £449 is a seriously good price for a trainer as good as this. Is it as good as a £1,199 Tacx Neo 2, or a £1,099 Wahoo Kickr? Overall that's a no, but then you wouldn't expect it to be directly comparable to a top-end unit, and it's not claiming to be.

It's more pitched to take on the likes of the £639 Elite Suito (read our review here) and the £699 (currently discounted to £599.99) Wahoo Kickr Core (review here), both of which have reviewed very well on road.cc. The Zwift Hub puts in a solid argument to be as good as either of those trainers, and it's substantially cheaper at just £449, including a cassette.

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If you want to get into smart training on Zwift without racking up a huge bill then it's ideal, and if Zwifting suits you it's good enough to cope with a decent training load at a fairly high level.

If you bought one and got hooked you might think about upgrading later on if, say, you got really into racing and you needed something with a more rapid power response. But it's plenty good enough to be my everyday trainer as a slightly-above-average category C racer, and even if I made it back up to B (not likely any time soon) it'd easily cope with anything that I could throw at it.

For the vast majority of people training indoors, the Zwift Hub looks like the one to recommend right now in terms of bang for your buck.

Verdict

The best budget smart trainer you can buy right now in terms of bang for your buck