Wahoo KICKR Core Zwift One Smart Trainer: Unboxing, Setup, and Full Review

Last week, Wahoo and Zwift announced their first-ever trainer collab: the KICKR CORE Zwift One.

It’s the KICKR Core we know and love from Wahoo, with a Zwift Cog installed in place of a cassette, and a Zwift Click included for virtual shifting.

I’ve had the CORE One (yes, I’m shortening the name) in the Zwift Insider Pain Lab for a few weeks, running it through its paces. And today I’ll be sharing my experience, along with key specs and other details. Let’s go!

Features and Specs

The CORE One is priced a full $1000 below Wahoo’s newest KICKR, the KICKR MOVE. And the CORE One comes with a full year of Zwift membership, while the KICKR MOVE does not!

So how do the two trainers compare?

Unboxing/Setup

CORE One setup is very easy. It can be done by just about anyone, even if you’re not an experienced cyclist.

Unboxing and Assembly

My CORE One arrived in the same box as a standard KICKR Core, but Wahoo says this will be changed soon. Assembly was quite easy:

1. Open up the collapsable front arm
2. Install both legs using the enclosed hex tool
3. Install the correct axle adapters for my bike (135mm quick release) – if you aren’t sure which adapters to use, read this post

Firmware Updates

Checking for firmware updates whenever you get new hardware is always a good idea. This is especially true with the CORE One, since it’s shipping with older firmware that doesn’t support virtual shifting or auto-calibration!

Installing the new firmware is easy using the Wahoo app (available for iOS and Android). I added the CORE One to my list of sensors, clicked it for details, then clicked the “Update Firmware” button and followed the instructions:

Note: when I installed the update, the app hung on the “Finishing up…” screen. After waiting for around 10 minutes, I restarted the app (which is a scary thing to do in the middle of a firmware update) and it showed the firmware as installed. The CORE One has been working fine ever since.

Bike Setup

I left my bike in a middle gear on the rear cassette, and it installed easily on the CORE One. After shifting up and down a few times I found the gear that was smoothest, and visually checked to see if it was lined up nicely on the cog. Good to go!

Ride Experience

Virtual Shifting

Of course, the big news with the CORE One is that it’s the first non-Zwift trainer to support virtual shifting. With virtual shifting, your chain doesn’t move between different rear cassette cogs when you shift. Instead, a virtual shift changes the resistance on your KICKR Core so it feels like you’ve changed cogs.

So how well does virtual shifting work on the CORE One? It works great! I tested it using the included Zwift Click and also the Zwift Play Controllers I already had installed on my Zwift bike. Both worked perfectly, without hiccups.

I will say the shift “curve” on the CORE One feels a bit different from the Zwift Hub – like a steady ramp up in resistance vs a quicker spike. But that’s not a bad thing… just different. Both trainers shift very quickly and smoothly.

One thing that isn’t mentioned much is that you must pair the CORE One via Bluetooth for virtual shifting to work. Then just pair the Zwift Click and/or Zwift Plays as well, and you’re good to go. The trainer automatically senses your gearing in the first few seconds of riding, then sets up your base resistance and puts you in 12th gear (you have a total of 24). And that’s it! Just use the Click’s +/- buttons, or the shift buttons on the Zwift Plays, to shift whenever you’d like.

I prefer the location of the Zwift Play shift buttons to the Click, because it’s reachable when my hands are in their default position on my hoods. Of course, if you’re on flat bars or some other setup, the Click may be better for you.

Noise Level

When it comes to noise levels, the CORE One is… cantankerous. It’s not the trainer’s fault – the actual KICKR Core trainer (flywheel, freehub, etc) is very quiet.

The issue is the Zwift Cog. I experienced the same noise issues with the Zwift Cog on the KICKR Core as I did with the Zwift Cog on the Zwift Hub. Specifically, there’s more chain/cog noise than I’d like.

But the noise level depends on your chain. And also your gearing.

I’ve tested the Zwift Cog with three different chains:

• The chain I’ve used for (literally) years on my Zwift bike (a YBN 11-speed chain)
• A nearly-new Dura-Ace 12-speed chain on my outdoor bike
• A new KMC 11-speed chain on my Zwift bike

All three chains received the same Molten Speedwax treatment, and all three have been tested to run near-silent on a standard cassette. None of them show as needing replacement when tested using Park Tool’s Chain Wear Indicator, although my well-used YBN chain is, logically, a bit stretched compared to the other two nearly new chains.

The Dura-Ace chain was the quietest of the three (+1 for expensive hardware, eh?), while my well-used YBN chain was the loudest. The KMC was somewhere in the middle.

I would characterize the noise level of the Dura-Ace chain as acceptable, while the other two are not. But I’m also fairly picky since I’m used to near-silent trainer setups!

As any cyclist knows, a noisy bike is an inefficient bike. When you hear drivetrain noise, you’re losing watts. So it hurts my cyclist heart to have a noisy chain/cog interface. It’s rough enough, in fact, that I can actually feel the teeth of the cog interfacing with my chain. That feeling is amplified the faster I turn my cranks.

This noise issue has been mentioned by other reviewers, too. Listen to DesFit do a nice comparison of the Zwift Cog vs cassette sound volume on the CORE One:

Zwift has always recommended riding in the little chainring when using the Zwift Cog + virtual shifting, and although they don’t say it, I can’t help but think part of the reasoning is because the Zwift Cog is quieter in the little ring. It’s quieter simply because the chain isn’t moving over the cog as rapidly. The faster the chain moves along the cog, the noisier it will be.

I may put together an article soon focused on taking apart the Zwift Cog and trying various things to make it quieter. What I’d really like to try is installing a cog from one of my spare cassettes, in place of the beefier steel cog used in the Zwift Cog, to see how that affects noise levels. Removing the plastic guides on either side of the cog will also reduce sound, but the truth is, Zwift needs to change something to make the Cog quieter.

The good news for KICKR Core owners is, you don’t need the Zwift Cog in order to enjoy virtual shifting. Just buy the Zwift Play Controllers, update your firmware, and you’re good to go on your existing cassette… which will be quieter than the Zwift Cog.

Power Accuracy

The KICKR Core’s new firmware brings what Wahoo calls “auto spindown calibration” to the trainer. This is just a wordy way of saying the trainer automatically calibrates itself for accurate power readings, so you don’t need to worry about doing it. Excellent news for KICKR Core owners!

Having completed several workouts, rides, and races with power dual recorded from the CORE One and my Favero Assioma pedals, I’d say my CORE One with its new auto-calibration is fairly accurate and close to being within spec… but it could use a bit of improvement.

First, as some other reviewers have already mentioned, you’ll need to put a hard ride or two into the CORE One before the auto calibration run enough to really dial in the accuracy. But that’s no big deal, and not unlike some other trainers.

My only real disappointment with power accuracy is that the CORE One seems to suffer from a bit of thermal drift, similar to the Zwift Hub. (Which is odd, since the CORE One has a thermal sensor, so Wahoo’s engineers should be able to compensate for temperature changes during a ride.)

Here’s an example (click to interact with the data):

My pedals were right with the CORE One when the ride began, but by the end the CORE One was reading around 5% higher. This is classic thermal drift, where a cold trainer reads higher the warmer it gets.

I’ve seen this on multiple rides, including sessions that began with the trainer already warm. Here’s a 90-minute ride that started with the trainer already warmed up. It’s reading a bit high to start, but even higher when the ride ends.

In these examples, if I’d stopped pedaling midride the CORE One would have recalibrated and probably improved in accuracy. But that shouldn’t be needed if the only issue is temperature.

You can see thermal drift again in my ZI Labs Power Meter test, where the CORE One reads a bit higher at the end than at the beginning:

That said, thermal drift isn’t apparent on all rides. Here’s a 40-minute race done just before the 90-minute ride linked above, and the CORE One is tracking nicely with my Assiomas throughout.

Oddly, I didn’t see the small-ring sprint issues that GPLama noted in his review, where his CORE One was rewarding him for being in the big ring (high flywheel speed) on sprints. The two sprints at the end of the workout above were done big ring (first sprint) little ring (second sprint).

Is the CORE One woefully inaccurate? Nah. It just appears that Wahoo’s engineers could tune the auto-calibration and/or temperature compensation algorithms to keep the trainer more firmly within the +/-2% accuracy specification.

Let’s be clear, though: compared to the days of manual KICKR CORE calibration, the auto-spindown feature is light years ahead, especially for the many Zwifters who rarely calibrate their CORE. My firm hunch is that this new auto spindown calibration will result in much more accurate power on average throughout the universe of CORE riders.

Inertial Feel

The CORE One’s 12lb flywheel is the same size as older KICKR trainers (generations 1-3). Many people say they can’t tell the difference between various physical or simulated flywheels, but I find the differences quite apparent, especially when accelerating my cadence or doing workout intervals.

The CORE One’s flywheel feels a bit better than the Zwift Hub, which makes sense since the Hub’s flywheel is a bit smaller. Still, the standard KICKR’s larger 18lb flywheel feels even better, which is partly why that trainer demands a higher price.

Wrapping It Up

Wahoo’s KICKR Core has the best reputation of any mid-range direct-drive trainer, which is why it commanded a price of $900 without a cassette for the first 5 years of its existence. Then Zwift entered the market with the bargain-priced Zwift Hub, a lawsuit happened, then a settlement… and here we are, with the KICKR CORE Zwift One available for $599 including a year of Zwift.

That’s a sweet deal, even if the Zwift Cog is noisy on some chains and power accuracy isn’t perfect.

With the CORE One replacing the Zwift Hub One moving forward, this is simply the best trainer for the money on the market today.

Questions or Comments?

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Wahoo KICKR Core Firmware Update Delivers Auto Calibration, Virtual Shifting

Wahoo’s KICKR Core is one of the most popular smart trainers in the world, and this week, Wahoo issued a firmware update (version 1.3.17) for the trainer, expanding its capabilities.

See Wahoo’s firmware release notes >

The firmware release coincided with the announcement of the new KICKR Core Zwift One trainer, so it would be easy to miss the news if you are one of the tens of thousands of Zwifters who already own a KICKR Core.

See below for details on the new features delivered by firmware version 1.3.17 and instructions on updating your KICKR Core’s firmware.

New Feature: Auto Spindown Calibration

With automatic spindown calibration, you no longer need to do manual spindowns to ensure accurate power readings from your KICKR Core. Instead, the trainer will automatically calibrate itself as you ride. (This is the same tech built into Wahoo’s flagship KICKR v5, v6, and MOVE trainers.)

How does this work? Wahoo says, “The trainer continuously monitors the motion of the large pulley wheel and flywheel. When the trainer detects coasting, it measures the drag in the system (resistance in the wheels, belt, etc) which allows us to recalibrate. This process only takes a second or two.”

Short answer? It just works. There are no downsides here… just more accurate power, automatically.

New Feature: Virtual Shifting

Virtual Shifting is a Zwift-specific feature that requires either the Zwift Click or Zwift Play Controllers. With virtual shifting, your chain doesn’t move between different rear cassette cogs when you shift. Instead, a virtual shift changes the resistance on your KICKR Core so it feels like you’ve changed cogs.

There are lots of benefits to virtual shifting, including flawless shifting, less drivetrain wear, and an expanded gear range. We’ve covered these benefits in more detail elsewhere, so if you’re curious, see “Virtual Shifting Expansion” on this post.

Upgrading Your KICKR Core Firmware

Installing the new firmware is easy using the Wahoo app (available for iOS and Android). Add your KICKR Core to your list of sensors if you haven’t already done that, then click it for details. From there, click the “Update Firmware” button and follow the instructions.

Note: when I installed the update, the app hung on the “Finishing up…” screen. After waiting for around 10 minutes, we restarted the app (which is a scary thing to do in the middle of a firmware update) and it showed the firmware as installed. The KICKR Core has been working fine ever since.

Questions or Comments?

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Wahoo KICKR CORE Zwift One Smart Trainer Announced

Zwift and Wahoo have announced a new smart trainer which is a collaboration between the two indoor cycling juggernauts. Named the Wahoo KICKR CORE Zwift One, this trainer combines Wahoo’s well-respected hardware and broad distribution network with Zwift’s innovative virtual shifting.

The result? A very capable smart trainer that is available to more Zwifters than ever before.

Today we’ll look at the new trainer’s specs and availability. A more in-depth review of the new trainer will be published separately.

What’s In a Name?

Wahoo KICKR Core Zwift One. The name is quite a mouthful, but it also describes this trainer nicely. The main “trainer” hardware is the same Wahoo KICKR Core we all know and love. But instead of a standard cassette, the single-cog Zwift Cog is installed, with a Zwift Click included for virtual shifting:

Simply put, the Wahoo KICKR Core Zwift One is a KICKR Core with a Zwift Cog installed. I’ll be calling it the CORE One for the rest of this post to keep things simple.

CORE One Specs

Built on Wahoo’s well-established KICKR Core line, the CORE One has all the capabilities required to deliver a high-quality Zwift experience. Here are the trainer’s key specs, with new features in bold:

• Zwift Click included for virtual shifting
• Calibration: automatic
• Cassette: Zwift Cog (compatible with most 8-12 speed bikes)
• Accuracy: +-2%
• Flywheel: 12lb
• Max Wattage: 1800 W
• Max Incline: 16%
• Cadence: built in
• Communication: ANT+ and 3-Channel Bluetooth
• Axle Compatibility: 130/135mm quick release, 12×142/12×148 thru-axle
• Weight: 18kg
• Physical Dimensions: 9″L x 23″W x 21″H (closed), 20″L x 23″W x 19″H (open)

Low Price, High Availability

The CORE One is priced very competitively at $599/£549/€599, the same price as the KICKR Core and the Zwift Hub. This price includes one year of Zwift. It is now available on zwift.com and wahoofitness.com.

The big news, though, is availability. Thanks to Wahoo’s distribution channels, the CORE One will be available via wahoofitness.com to customers in Australia and Canada beginning in late March! This is great news to Zwifters in both markets who haven’t had access to the Zwift Hub (which is only sold in the US, UK, and EU).

Virtual Shifting Expansion

Wahoo is now rolling out a firmware update (version 1.3.17) for all KICKR Core owners which, among other things, enables virtual shifting in Zwift. If you own a KICKR Core and Zwift Plays or Zwift Click, you can begin using virtual shifting as soon as you update your firmware.

What exactly is virtual shifting? With virtual shifting, your chain doesn’t move between different rear cassette cogs when you shift. Instead, a virtual shift changes the resistance of your smart trainer so it feels like you’ve changed cogs. This is how smart bikes like the Wahoo KICKR Bike, Wattbike, StagesBike, and Tacx NEO Bike have always worked.

Why do Zwifters like virtual shifting? Because it beats mechanical shifting in several ways:

• Fast, smooth, quiet: with no chains skipping between cogs, your shifts are completely silent, perfectly smooth, and lightning-fast.
• Less wear and tear: your chain won’t wear out as quickly, and neither will the Zwift Cog, since it is built beefy because weight is not a concern.
• Shift under full load: no need to ease off the pedals when shifting under power, as your chain isn’t going to “skip” when virtual shifting like it can with mechanical shifting.
• Compatible across many bikes: no more spinning out on your low-geared mountain bike, or needing to swap cassettes if you swap bikes. Virtual shifting works with almost any 8-12 speed bike and auto-calibrates to your physical gearing.
• No more fine-tuning: many riders have to fine-tune their physical shifting when moving between outdoor riding and a direct-drive trainer, since the cassettes aren’t lined up exactly the same. The Zwift Cog doesn’t require any such fine-tuning… just shift to a physical gear that has your chain lined up straight on the Cog and you’re ready to ride.
• Expanded gear range: Zwift’s virtual shifting currently supports a virtual 24-speed setup, which is more gears than most riders have on their outdoor setups. Additionally, the gear ratio range is very wide (from .75 to 5.49), meaning everyone should find that virtual shifting offers more easy gears and more hard gears than your mechanical gearing.
• In-game visualization: with Zwift’s virtual shifting, you can always see what gear you’re in on screen.

Zwift’s virtual shifting was rolled out to the Zwift Hub in late 2023, and it’s arguably the most significant technological advance we’ve seen in smart trainers in years. The CORE One is the first non-Zwift trainer to support virtual shifting, and that’s big, good news for Zwifters. I bet virtual shifting will be rolled out to many more trainers, with Wahoo’s flagship KICKR being one of the first, as consumers begin demanding this functionality.

CORE One vs Hub One

Wahoo’s CORE One compares favorably to the Zwift Hub One, matching or improving on the Hub One’s specs in almost every area:

As you can see, the Hub One only wins when it comes to offering 10Hz race mode and heart rate monitor bridging. (Both of these features could be added by Wahoo via a firmware upgrade. But Wahoo may choose to reserve those “premium” features for their high-end trainers.)

You may recall that back in November 2023, Wahoo dropped the price of the KICKR Core and began offering it with your choice of cassette. At the same time, Zwift stopped selling the Zwift Hub classic, effectively replacing it in their store with the repriced Wahoo KICKR Core.

Zwift still has the Hub One trainer listed for sale, but the new CORE One will be replacing the Hub One. (Zwift says they will continue to support the Hub and issue Hub firmware updates for the next two years.)

Buying a Zwift Cog for Your KICKR CORE

Zwift tells me a Zwift Cog + Click upgrade pack will be available in the future for KICKR CORE owners who wish to replace their cassette with a Zwift Cog, but it is not yet in stock. It’s worth noting that the Zwift Cog for sale on Zwift.com will not work with KICKR CORE trainers, as the freehub is incompatible.

For now, you can enjoy virtual shifting using your Play Controllers and existing cassette. I’ve done it myself, and it works swimmingly.

Conclusions

Today’s announcement is all good news, as I see it. The Wahoo KICKR CORE Zwift One is a capable successor to the Zwift Hub One: more accurate, more connected, compatible with the KICKR Climb, and backed by Wahoo’s industry-leading support. It will also be available to more Zwifters, including riders in Canada and Australia!

And while the new trainer offering may grab the headlines, the bigger news may be virtual shifting arriving for a huge new chunk of Zwifters. With thousands of KICKR Core trainers already in use on Zwift, virtual shifting is now just a firmware update (and perhaps a Zwift Play purchase) away!

As I said above, I’ll be publishing a review of the CORE One soon. Until then, here’s a review from our favorite Aussie Lama:

And DC Rainmaker:

Questions or Comments?

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