The best treadmill reviews you can trust
The Sole ST90 is a slat belt treadmill with high-end features and a matching price tag. I review the Sole ST90 treadmill’s pros, cons, and performance to help you decide if this treadmill deserves a spot in your home.
Updated: November 9, 2023
Sole takes a page out of Peloton’s book for this one–the Sole ST90 is a motorized slat belt treadmill with a hefty price tag. In light of Peloton’s woes, Sole smartly included a rear shield to prevent anything (or anyone) from being sucked under the ST90’s deck. Sole has also equipped the ST90 with its new interface of training and media features, so you will never get bored while training on the ST90. The touchscreen display is a moderate size of 15.6 inches and is comfortable for viewing entertainment and training content. Part of the ST90’s major appeal is the ability to disengage the motor for manual training. This review of the ST90 recounts my experience actually testing out this awesome cardio machine.
The Sole ST90 has a z-shaped frame, so the screen looks like it is almost hovering over the front of the deck. It is hard to say that I like this design for the ST90, because while it looks nice, the console is not quite as stable as I would like. The ST90 could have done with a little more stability, which would have earned it a point back on our build rating. Yet, the ST90’s frame is not bad. I could still watch all the training and entertainment content with little issue.
The frame is metal with a black powder coating. There are hints of Sole’s signature red and large white branding along the sides. The footrails are grippy enough to feel supportive. I had no problem jumping from the belt to the footrails if the belt started running away from me. The handrails could use a little more texture. They are a minimally textured plastic, whereas I would have liked a soft rubbery coating for this price point. The rails are sturdy, but they miss some of the high-end refinement, which likely will bother very few users.
The motor is a 2.0 HP AC motor. Because this is an AC motor, it defies our typical ratings for motor horsepower. The ST90 is perfectly capable of supporting running and daily use. As an AC motor, it is a bit louder than its DC counterparts. The ST90 is not ideal for users hopping to minimize treadmill noise. For reference, it is quieter than the discontinued Peloton Tread+ and has faster speed and incline adjustments.
The motor is beneath the deck. I cannot be certain, but while testing, I felt more vibrations underfoot than normal. I speculate that the motor’s placement has something to do with this. Yet, I could be wrong. Either way, the vibrations didn’t interrupt my run; it was simply an unexpected sensation.
The ST90 is a slat belt treadmill. It has a spacious 20” x 60” running surface with a 10-inch step-up height. There is plenty of space to lengthen your stride. The console is positioned a little further back on the deck to keep you from stepping off the front of the treadmill. There is no motor hood due to the motor’s positioning under the deck. It can take a little time to get used to this construction, but there is very little chance of stepping off the front of the belt.
The belt provides soft cushioning, but not as much spring as some runners may prefer. This design is best for runners who want the shock absorption but don’t want to feel like the treadmill is helping them run. The ST90 feels a bit more difficult to run on than other motorized, cushioned treadmills. It is a great way to increase your training intensity.
The ST90 is a non-folding treadmill that weighs nearly 400 lbs. I recommend having a set place in your home to locate it, because it is not easy to move. The ST90 is best for users with dedicated workout spaces, like a home gym. Placing the ST90 in an enclosed space allows you to keep pets and children away more easily. Sole has taken measures to ensure that nothing unintended gets caught between the slats, but we advise exercisers to err on the side of caution. Really, pets and children should be kept away from any treadmill of any kind.
The ST90 has an incline range of 0 to 15%. While in manual mode, the ST90 is restricted to an 8% incline maximum. There is no option to decline the treadmill, which may be a letdown for some users. Many high-end treadmills have decline, so it is a definite sacrifice to get a slat belt treadmill like the ST90.
The ST90 has a large onscreen button labeled ‘Free Mode.’ This training option allows the user to train with the treadmill belt disengaged. The deck can then incline from 0 to 8%. You retain control over the incline throughout the free-mode exercise. The belt is difficult to bring up to a running pace, especially for smaller users. Yet, it’s perfect for sled pushing or walking. Exercise in free mode is intense, but it is just one more way the ST90 is versatile. I appreciate that the ST90 can be so easily placed in manual mode, as other treadmills require more complicated processes or for the user to step off the treadmill.
The Sole ST90 has the abundance of features that Sole equips their folding treadmills with. Users familiar with the F80 and F85 will find a very similar interface on the ST90. Sole provides one some of the most versatile content and features on the market. From smart features to low-tech necessities, the ST90 has it all, but somehow, the console never feels cluttered.
The ST90 has a floating console with a large screen. The console has large buttons. There are speed and incline buttons along the sides for making quick changes from one setting to another. The buttons do not represent the entirety of the speed and incline ranges, which can be a little frustrating. The ranges aren’t bad, but there is no quick adjust button for making the belt level. This is a strange choice, but I think most treadmill users will be able to live with it.
Toward the bottom of the console, you will find a start and stop button surrounding the safety key. The only other button on the console is the fan button. With such a large console, the ST90 could have used a couple more buttons. In particular, I would have liked to see a volume button, though the volume can be adjusted onscreen or with your headphone controls.
The ST90 has a 15.6-inch touchscreen display. It has good graphics, but it isn’t quite up to par with watching content on a 4k TV. The screen is moderately sensitive. By this, I mean that I occasionally had to press the screen more than once to select the button I wanted, but it was not so sensitive that I ended up pressing buttons unintentionally. Sole’s interface is pretty easy to navigate. New users would benefit from reviewing the manual, but it is not necessary. Most users should have no trouble getting comfortable with the ST90’s layout.
The ST90 has two large cup holders. These cup holders are each bordered by a small item storage compartment. Sole has handily placed icons next to these compartments, demonstrating that you can put your keys, phone, or remote inside, for instance. They would also come in handy for runners stowing nutrition to use during their long treadmill runs.
The ST90’s fan could use some improvement. In addition to being weak, the fan has a strange angle. It points at an angle away from the user. It may provide minimal relief for users who don’t like a fan blowing directly on them. It has three-speed levels, but I didn’t find any of them particularly useful.
The ST90 has a device rack at the top of the console with an adjustable clip. The console’s shaking can cause the device rack to rattle, particularly if the adjustable clip is not pushed all the way down. If you are hearing a creaking noise, make sure this is not the cause. The device rack functions really well with a device inside of it, and the noise immediately went away. The height of the device rack is really good, so most users should be comfortable viewing it. If anything, it was a little on the taller side.
The speaker quality is decent, but not as clear as other treadmills I have tested. I had no problem with the volume level. The sound just wasn’t quite as crisp as I expected.
The Sole ST90 is Bluetooth-compatible. It can pair to the Sole+ app or with a Garmin watch. The audio is also Bluetooth, so you can pair a smartphone to play audio through them or pair Bluetooth headphones for quiet listening. The sound quality is much better when listening through my headphones, though that will largely depend on the quality of your headphones rather than the treadmill’s capabilities.
The wireless charging pad is great for compatible devices. Unfortunately, not all phones are able to charge wirelessly, but this does seem to be the general trend that smartphones are moving in, so it was a great choice for Sole to include. Thus, you can use your device to screen mirror or play audio without worrying about your battery life.
The Sole ST90 supports screen mirroring for iPhones. While Sole previously had an app to make this possible for Android users, it is now out of date. When I try to install the app (at the time of this review), the Google Play store notifies me that the app was built for a previous version of the Android operating system. Our iPhone-owning reviewers inform me that the connection between Sole’s interface and their phones is just fine. The quality is not as good as the native content, but that is standard across most mirrored device connections.
At the very front of the console, there is a stability bar. This bar provides users with extra support. It is flat on the top and bottom with rounded edges. The top is equipped with two pulse grip sensors. These sensors provided comparable readings to my Garmin watch. The sensors are not practical for runners to use during their activity, but it is a comfortable hand position for walking. In fact, I lost a few steps toward my daily step goal, because my hands naturally gravitated towards this bar.
Sole readily advertises the ST90’s compatibility with Garmin fitness wearables. My Forerunner 245 connected as intended. The only hiccup in the process is that your phone must first be disconnected from your watch before you can connect to the ST90. I would much rather a treadmill connect with my watch through heart rate broadcasting or as a sensor/accessory. Connecting the ST90 as a phone prevents me from getting notifications from my phone, which can be nice while I am busy exercising. Perhaps Sole plans to increase the integration between its treadmills and Garmin in the future to include more features beyond heart rate monitoring.
The ST90 has included a few safety features in addition to the running belt’s rear guard. The treadmill can detect when a user is on the belt. Thus, if the belt is moving but a user is not detected for ten seconds. The workout will be ended after five minutes displaying the safety pop-up. This feature only engages if the belt is running at a speed of 2 miles per hour or higher. In my testing of this feature, I found mixed results when I was standing on the footrails. It is possible that standing on the footrails and holding the handles prevents this feature from engaging, which makes sense. Being on the footrails is not the same as being off the treadmill entirely.
There is also a child lock. This feature requires the user to hold down the start and stop buttons before the treadmill can be started. The speed and incline quick adjust buttons are up high, and the speed and incline switches cannot be held down to rapidly change speed or incline.
The Sole ST90 is a powerful running treadmill with unique features. The slat belt and motorized design. The ST90 can feel muted underfoot. This means it has great shock absorption but very little bounce. If you are looking for a tough workout, this is it. Because the deck doesn’t have a lot of bounce and absorbs a lot of the energy you are creating with each step, the treadmill is making you do more eccentric work. This makes the workout harder, kind of like running on sand or thick grass.
The speed and incline switches near the stability bar are the easiest way for me to adjust speed and incline while training. They can be held down for fast adjustments, but you might have to hold them down longer than you think. Once they start adjusting, the adjustment does pretty quickly. This delay is likely a safety mechanism to prevent users from accidentally adjusting their speed or incline too fast.
The ST90 is really for runners or walkers who want to take their cardio up a notch. Maybe you don’t care about how fast or far you are running; you just want a quality workout. The ability to disengage the belt and put yourself to work shows the ST90’s strengths. Exercise is meant to be challenging–that’s how we grow stronger and more efficient. The ST90 is for those who want to be pushed to that next level. The ST90 didn’t cut me any slack like the NordicTrack Commercial 2450 might.
Sole excels for the onscreen content. Instead of locking you into one training platform, Sole throws the doors wide open. On the ST90 you get several interval workouts and military tests built into the treadmill. You also have the ability to program your own workout in just a few steps. If you complete a workout that you might want to do again in the future, Sole allows you to save the workout as a template.
The Sole ST90 does not require a subscription to access any of its features unless required by the third-party app. For example, you need a Netflix subscription to access Netflix’s content, but you don’t need a subscription to Sole to access Netflix. In addition to Netflix, the Sole ST90 has apps for Prime, YouTube, Audible, CNN, ESPN, Hulu, Max, Disney Plus, and Peacock. With a good WiFi connection, you should have no trouble watching your favorite shows and movies.
For other training opportunities, the Sole ST90 also includes an app for Kinomap. This app is a virtual training app that takes you on routes around the world. The incline will automatically adjust to mimic the real-world grade to give you an immersive experience. Kinomap offers a free trial and some free content. After the free trial, you will have to pay to continue to access most of its content.
If this is not enough training, the screen mirroring ability allows users to access content from other training apps like Peloton, iFIT, and more. This way, you can train alongside whatever platform you wish.
The Sole ST90 Treadmill is a high-end treadmill with a powerful AC motor. The treadmill is great for runners with the dedicated space for such a machine. It is an intense training tool that doesn’t offer to do any of the work for you. Yet, the belt has a decent amount of cushioning. Sole has taken steps to provide the ST90 with a good amount of safety features, though users should still keep their pets and children away from the treadmill while it is in use. The ST90 offers great onscreen content for training and for entertainment. Walkers and runners trying to avoid a monthly subscription should be happy with the free offerings found on the ST90.
