Not just this month, either. Almost exclusively throughout the second half of 2018, in fact, mixed up with sessions on the Wattbike’s less tech savvy sibling (the Pro) and just very occasionally, if I’m feeling really adventurous, a ride on a real bicycle, in the fresh air (I'm currently nursing an injury).


The story of the Atom started with Wattbike wanting to tap into the smart trainer market. With the rise of Zwift, the hugely popular online training game, Wattbike was losing out to rival home trainer companies who offered systems compatible with it. The original Wattbike, which hasn’t been replaced by the Atom but is a companion to it, was itself a phenomenon. I've seen them scattered round the world far and wide, whether it's with athletes from other sports using them to train on, Japan’s keirin racing school or the British army, who incorporated it into their training assessments. Wattbike has become ubiquitous in the indoor training market in a relatively short period.

I have the luxury of having access to both. The Pro resides in the basement at work. It doesn’t need to be plugged into anything, only needing power for the head unit, which, if it’s working correctly, is powered through workouts. The Atom is in my living room, plugged into the wall, with my iPad deployed as the head unit, as the cheaper Atom (£1,599 to the £2,250 of the Pro) isn’t sold with one.

Atom_08_18 Top View iPad App

The Atom addresses the main issue I’ve always had with the Pro, which is that resistance can’t be changed without having to awkwardly bend down and adjust it manually, either with the air resistance (the lever on the left side) or magnetic (the cog on the right). Resistance on the Atom is changed via buttons on the inside of the hoods on the handlebars. The hood covers have a tendency to slip from their position on the bars, though, and I need to pull them back on every so often, as when they slip you lose the position of the shifters and end up shifting down when you want to go up.

It’d also be good to get some tactile feedback when you do shift gear. You can hear the gear changing in the Atom’s guts, but nothing comes from the shifter itself. It’s a similar problem to when electronic shifting was introduced to road bikes and why many still prefer mechanical shifting. Neither does the gear change within the crankset feel anything like the gear change on a bike. These are problems some may easily see past, but plenty will go the other way.

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I use the Wattbike Pro almost exclusively in air resistance mode. It feels more like riding a bike than the magnetic resistance and unless I want to do some low cadence work, air gives me enough resistance to work with.

The Atom is entirely magnetic. I don’t think it has the smoothness of pedal stroke of the Pro, but at the same time it is quieter. Living in a first floor flat, the noise of a turbo put me off using one but I’ve had no complaints so far about the Atom. It weighs 44kg, which means you don’t really want to have to move it once it’s in place, but it also means it’s extremely stable once you’re working out on it. There’s no rattling or movement that you might get from a turbo that connects onto your bike.

In terms of the Atom’s exterior unit design, it has excellent adjustability to fit a wide range of rider sizes, but I've got a couple of niggles. The first is with the seat post and front end; you need to tighten it so hard to get them to stay up, to the point where you think you might be doing damage, to both the hardware and your hands. In both seat and front ends, even when they're tightened so they won't fall down, there can still be movement forward and backward.

Another is that, such is the design of unit, you can’t remove or attach your pedals with the crank in the six o’clock position, like a road bike or even the Wattbike Pro. There is only a small area, in the 3 o’clock position, for you to fix your pedals. It means you don’t want to overtighten, as you can’t get much leverage like this. To be more positive, it’s good that the saddle can be swapped easily, and you can even fit your own handlebar. Not that I've wanted to, because the stock bar comes wrapped with tape (unlike the Pro) and fits just fine.

Atom_08_18 Pedal Detail (1)

The Wattbike app, like the head unit on the Pro, is useful primarily for the graph that shows how effective your pedalling is. Like the Pro, the app shows how power is distributed but also how smooth your pedal stroke is and the boundaries in which to maintain your smoothness. Using it aids muscle memory which you can take over to the road. In terms of training programmes, there’s a fairly interesting function that allows you to climb real life mountains such as Alpe d’Huez in France and, a little closer to home, hills like Winnats Pass. It’s a 2D representation, however, so following your progress up a graph is nowhere near as engaging as, say, climbing Alpe du Zwift.

Zwift, the virtual reality training game, is what I've used the Atom for 99% of the time and the context for which this review was built around. Being a smart trainer, the resistance adjusts with changes in gradient of Zwift’s world. Climb up a mountain and your effort will be rewarded with a speedy, free-wheeling descent, and with adjustable gears you can climb by either spinning quickly in a low gear or grinding it out in a high one. In ERG mode, the road gradient is ignored and resistance is automatically adjusted to correspond with the power required for that particular interval.

Atom_08_18 Handlebars iPad App

Following prescribed training plans or workouts is when the Atom is at its best when it comes to Zwift. My favourite session is the over/under – five minute intervals for 50 minutes at watts just below your FTP (functional threshold power – the highest watts you can produce in an hour, and the basis for how all training plans are calculated on Zwift).

Such sessions work because you’re not having to change resistance or gear very often – and it’s in changing gear quickly, whether in climb or ERG mode, where the Atom struggles on Zwift. There is a lag between clicking the gear and it actually changing, which means that, if you’re in a race and the pace suddenly increases, it takes a while to adjust your ideal resistance. The race might have already disappeared up the road and this makes for a frustrating experience. The same is also true if the power target for an interval increases sharply, say from 200 watts to 600w. In such circumstances, I’d find myself grinding to a halt, such was the huge load put onto the cranks and I'd have to use my entire body weight to get the them turning again. This is my biggest frustration with the Atom and it often makes for a staccato experience.

I’ve never used ERG mode on any other smart device so I don’t know whether it’s a universal problem, but on the Atom things get frustrating. Because resistance automatically adjusts to keep you at a set power, once you fall below it, the resistance increases and your cadence slows – to a standstill, if you’re not careful. You need to increase your cadence to reduce the resistance, but sometimes it’s just too difficult to do so.

While completing workouts on Zwift in ERG mode, you work through your intervals and get awarded stars for each interval you complete successfully. I've found it's far easier to hit mid-range power intervals than anything at either extreme. The Atom doesn't cope well with very low or very high powers - my least successful intervals are when I'm trying to maintain 60 watts.

In terms of power accuracy, I’ve not tested this side of it. I don’t use power to ride on the road, so it’s never concerned me what reading it gives me – it’s simply a tool to keep me fit indoors. Other reviews I’ve seen attest to Wattbike’s claim of it being +/- 2% accurate.

So the Atom is far from faultless. Its biggest problem – the gearing – appears to be fixable through firmware, and thus far Wattbike has been good at releasing updates that provide solutions. But there's still plenty of room for improvement. My Atom is currently operating on the most recent update and the gearing issues feel like they’ve come on since I started testing in the summer, but there’s a way to go yet.

I’ve enjoyed using the Atom, despite its flaws, but a lot of this may be because of the playability of Zwift. The Pro remains my go-to Wattbike, which offers a more satisfying training experience. The Atom may be 'smart', but its IQ flatters to deceive when it comes to comparison with its sibling.

UPDATE: 18 December 2018, firmware 3.5.1

The Atom of late 2018 is a more pleasing product than the one I received in the summer. Gear changes are faster to take effect, though I'm still wary of changing too many at a time and I still think it's a product that prefers stability rather than flux. Which means I still think it's better in ERG mode on Zwift than following the world's gradients. For example, in the latter, if you try a sprint effort on a hill and you're in the ideal gear, if the gradient suddenly flattens out, the subsequent reduction in resistance is hard to counter through a raising of gears, as this can be slow if you're adding a lot at the same time. The Atom is a somewhat quirky proposition in Zwift; the more I use it, the more I get used to its rhythms, in particularly the way the gears shift and time it needs to take effect.

One great development is the absence of the 'clamping' that would happen in ERG mode, when far too much resistance would be loaded on during short, high power intervals and bring me to a halt. It's opened up the variety of training workouts I can do, and I no longer have to be afraid of choosing plans with sprints in them.


Obviously there's nothing than can be do about the hardware problems, such as the bolts that tighten the seat post and front end, but they were always more minor issues when compared to the riding experience, which is much more satisfying than it was. One might argue that Wattbike released the Atom before it was finished, but to their credit they've continued to work on the user experience. It will be interesting to see where it goes from here, given how modifiable it is through firmware updates.