Popular among Brits and various national track teams, Wattbike was first to the smart bike scene in 2017 with the Atom.
Quiet, stable, reliable power measurement, relatively easy to move around, visual analysis of pedal stroke on the Wattbike app
Only comes with 170mm cranks; saddle fore/aft and stem adjustment require Allen keys; shift buttons are in an awkward spot; no accessory tray or USB chargers
The Atom is a good solution if you ride 170 cranks and don't plan on sharing the bike with other riders. It's quiet and plays relatively well with Zwift, but shifting is vague and the shift buttons under the hoods limit hand positioning.
One size (57-83cm saddle height)
97lb / 44kg
If you’re committed to regular indoor training and to investing in some interactive gear, then smart bikes are certainly worth taking a look at along with smart trainers. The team at Wattbike has worked for years with world-class athletes and gets the training part as well as anybody; the fine details on the Atom, however, aren’t as user friendly to a broad range of users as perhaps the world’s elite track cyclists or triathletes.
Like any other smart bike or smart trainer, the Atom both measures power (quite accurately, in fact), and automatically adjusts resistance to match either the undulations of a virtual course or to the resistance specifications of a structured workout.
Wattbike Atom parts overview and adjustability
The Atom’s stability is excellent, even under hard sprints. Each of the four feet are height adjustable, and the whole bike wheels around easily with two coasters.
The fit can be adjusted for a wide range of riders, and hash marks on the seatpost as well as the cockpit fore/aft adjustment allow for precise points of reference for readjustment if shared between multiple riders. However, unlike other smart bikes where all adjustments are done with quick-release knobs or levers, the Atom requires Allen wrenches for a few of the adjustments, including the saddle fore/aft and the effective stem length. If you’re just going to use the bike yourself, this is no big deal; you’ll set it once like your outdoor bike and forget it. If multiple people are sharing it, then it’s inconvenient.
The handlebars are normal 31.8 bars, and your could even swap in your own if you like. The bike comes with clip-on aerobars that have a phone/tablet holder at the ends. If you like riding with aerobars, this is probably a good thing. If you don’t, it might be annoying to choose between having a built-in tablet holder or getting rid of the aerobars that can block the tops of the handlebar.
Another divisive component choice is the 170mm cranks. If this is your preferred length, great! If not, well, tough luck. Atom’s newer competitors Tacx, Stages, and Wahoo have between three and five crank-length options.
The Q factor is 160mm, much closer to a mountain-bike configuration than a road bike. (Shimano XTR is 158mm; Dura-Ace is 146mm.)
The sound is very quiet. I measured it at 64dB at 200w/90rpm, which is inline with the other smart bikes on the market and quieter than many smart trainers.
Atom power accuracy and analysis
I tested the power measurement with a set of Garmin Vector 3 pedals, which I have in turn tested against other power meters and a host of smart trainers and found to measure reliably. When I test smart trainers, I use at least two meters simultaneously, but due to the nature of smart bikes, you can only use a single set of power-meter pedals for reference. So, take this with a grain of salt.
All that said, the Atom measurements tracked gratifyingly close to those of the Vector 3 pedals. With the example above, for instance, there is a single watt difference in average power (193 to 194). You can honestly get a higher variance sometimes using a single power meter with two head units recording, if one unit happens to catch a data packet and another unit does not.
Bottom line here: I would happily trust the power data on the Atom for any training or racing.
In addition to basic power measurement and resistance for training and virtual riding, the Atom also offers some cool analytics with its corresponding app, where you can see exactly where in your stroke you are and aren’t applying power. I could never get the app to work well on my phone (an iPhone 6), so I can’t comment on the app.
Ride feel and features
The initial WattBike had a large resistance dial akin to a gym bike. The Atom features shift buttons that work in linear fashion, with 22 virtual gears, not like a replication of Shimano or SRAM shifters. WattBike has integrated with Zwift so when you shift you can see the gear change briefly on screen, which is nice, but the gear changes themselves feel a bit vague compared to the crisp shifts on the Wahoo Kickr Bike and the Tacx Neo.
The shift buttons are easy to press — arguably too easy to press, if you often ride with your hands on the hoods. I found I would sometimes accidentally shift when pulling on the hoods, as when out of saddle climbing.
The pedaling feel is nice and smooth. Resistance holds steady when doing structured workouts, but there is still a bit of flexibility in your cadence, which is nice. Quick elevation changes on some Zwift courses, however, can feel a bit abrupt in resistance changes.
Unlike a smart trainers, where there is often a bit of a pivoting feel as the entire bike is stabilized just at the rear dropouts, with the Wattbike Atom the entire structure feels solid and planted.
The Atom vs the competition
Wahoo changed the smart-bike landscape with its Kickr Bike, which tips up and back to mimic elevation changes. As the Kickr is quite new, the reliability of that unit has yet to be proven. Smart trainers sometimes fail and need to be returned and refurbished. This can be annoying, but not overwhelming. A smart bike, on the other hand, seems pretty daunting to have to return if you needed to.
Wattbike offers a two-year guarantee on the Atom, and also a 30-day money-back guarantee if you don’t like it. That, in my book, is a good deal.
The shifting on the Kickr and the Tacx Neo are better than the Atom. In those bikes, the electronic motor stutters for a micro-second, which nicely replicates the feel of shifting outside. The Atom feels like the StagesBike, which you can definitely tell a difference in your cadence, but the transition overall between ‘gears’ is much softer and less distinct.
The phone/tablet holder isn’t great. On the Kickr, there is no device holder at all; on the Stages and Tacx bikes, you have a shelf and a device securing spot, plus USB chargers.
The Kickr and the Tacx have wide top tubes that may rub the legs of many riders. The Atom does not have that issue.
Stability wise, the Atom is better than the Kickr and as good as the other two.
The Atom benefits from Wattbike’s long history of indoor training with elite athletes. With rock-solid stability and excellent power measurement, it’s a no-nonsense training tool. Unfortunately, it’s not quite as user-friendly to a wide group of riders as the other smart bikes out there, as you have just the single, 170mm crank option, the clip-on aerobar tablet holder, and two fore/aft adjustment points requiring Allen wrenches.
The price is relatively good, and the 30-day money-back program and two-year guarantee are confidence-inspiring.