Everything You Should Know Before Buying Sole’s ST90 Slat-Belt Treadmill [A Review]

With the ST90, Sole has stepped outside of their comfort zone and created a treadmill with two firsts for the brand.

Not only is it their first (and only to date) slat belt treadmill, but it’s also their first treadmill to come with an AC motor – both of which are pretty big deals.

The rugged slat belt offers a durable yet cozy running surface and the AC motor is designed to be able to handle hours of continuous use day in and day out.

The ST90 also comes with a large running surface, 15 levels of power incline, and an updated 15.6″ touchscreen console that comes pre-loaded with entertainment apps, free streaming workouts, and screen mirroring.

The warranty on this treadmill is surprisingly short for a Sole product, but otherwise, there’s a lot to get excited about here.

All things considered, I think Sole’s ST90 would be a great option for runners looking for a treadmill that can handle some serious mileage.

But before you buy, you gotta know what to expect – and that’s where I can help.

In this review, I’ll go over all the specs and features this treadmill has to offer, but I’ll also compare it to some of the other top treadmills in it’s price range to see how it stacks up.

After reading, you’ll be well-equipped to decide for yourself whether or not the ST90 is worth investing in.

Sole’s ST90 is a heavy-duty treadmill with great performance specs and console features, but the warranty is a bit short for a treadmill in the $4k price range. Serious runners and families with multiple users will likely appreciate the durability of the slat belt, but more casual users may want to consider a more affordable option.

Sole’s ST90 Treadmill

It’s no secret I’m a Sole aficionado.

I praise pretty much all their products and you’ll usually find one of their machines at the top of my “best of” lists each year.

And no, Sole doesn’t secretly pay me off to do this – I do it because I like how straight forward Sole machines are.

Sole products are heavy-duty, easy to use, and usually packing better performance stats than any other machine in its respective price range.

Plus, I appreciate the extended warranties Sole usually offers, but more on that in a little bit.

Even though I think Sole’s bikes and ellipticals are just as high-end, it’s their treadmills that usually get the most attention.

This might be because Sole started out as a treadmill provider, but who knows.

Anyway, as I mentioned above, the ST90 is the brand’s only slat belt/AC motor treadmill to date.

And with an asking price around $4k, it’s also their most expensive model (it costs about $1k more than their new F89 treadmill).

Pros

• 20″ x 60″ running surface
• 2.0 CHP AC motor
• Slat belt
• Heavy-duty frame
• 400 lb weight limit
• 15 levels of incline
• Manual mode
• 15.6″ touchscreen console
• Built-in entertainment apps
• Free fitness streaming through Sole+
• Convenient rail speed/incline controls
• Bluetooth speakers
• Wireless charging port
• Heart rate monitor compatible
• Tablet holder
• Easy assembly

Cons

• Warranty could be longer
• No cooling fan
• Doesn’t fold

Running Surface

A treadmill’s running surface is a simple spec that tells us exactly how much room we’ll have while using said treadmill.

Personally, I think this is the most important spec to consider because it instantly tells me whether or not I should be interested in this treadmill.

And if the running surface is too small, I won’t even look at the other specs.

And that’s because regardless of how powerful the motor is or how many great features a treadmill has, if it’s too small for me to comfortably stretch out on while running, I know I won’t be happy.

Most higher-quality treadmills come with a running surface of at least 20″ x 60″ because at this size, most folks of all heights will be able to comfortable run as fast as they want without running out of space (pun intended).

And the ST90 comes with a running surface that measures 20″ x 60″, so space shouldn’t be an issue.

More interestingly though, is the fact that the ST90 comes with a slat belt.

We see slat belts on all the top curved manual treadmills, but there haven’t been that many traditional motorized treadmills taking advantage of ’em yet.

Woodway comes to mind – they might’ve actually been the first ones to use slat belts… I think Peloton’s Tread+ also comes with a slat belt, but there aren’t many home models that do.

Slat belts are generally considered a step up from traditional belts because they’re better at shock absorption and help reduce strain through joints.

They also tend to provide better grip with shoes, resulting in a more comfortable running (or walking experience).

Slat belts are made up of individual slabs of rubber, which are usually thicker than traditional belts, allowing the slat belts to last longer as well.

With a spacious, slat belt, the ST90 could be a smart choice for folks looking for a comfortable, durable treadmill.

Folks prone to injury or dealing with aching joints will likely appreciate the thicker, softer belt.

Something else worth noting is how ridiculously heavy-duty this treadmill is.

With an assembled weight of 326 lb, you shouldn’t have to worry about this treadmill feeling anything but rock solid and stable during workouts.

It also comes with a max weight limit of 400 lb, which is high enough to accommodate folks of all sizes.

Overall, the ST90 scores highly with its large running surface, heavy-duty frame, and high weight capacity.

Motor

Ok, so the ST90 scores highly in the running surface department, but let’s switch over and talk motors.

The ST90 comes with a 2.0 CHP AC motor that can reach a top speed of 12 mph and it has 15 levels of power incline.

With a 2.0 CHP rating, you might conclude that this treadmill is weaker than most of the other top home treadmills, but we’re talking about an AC motor here.

Most home treadmills come with a DC motor – especially at this price range.

DC motors are found in most home treadmills because they’re more affordable; AC motors are found in most commercial treadmills though, because they’re more efficient and better able to tolerate prolonged running.

AC motors are designed to run for hours at a time without overheating, making them a smart choice for commercial gyms where it could be under repeated use by multiple users.

An AC motor could also come in handy for homes where there are multiple family members using the same treadmill or a single user who may run for hours at a time.

Like marathon runners.

FYI, giving a treadmill an AC motor usually immediately sets the price over $4k

The ST90 also comes with 7.44″ rollers, which is huge compared to the 2-3″ rollers found on your traditional belt treadmill.

By the way, the rollers are what the belt makes contact with, allowing it to glide smoothly over the deck and having larger rollers is a good thing because it makes for a smoother feel, while putting less stress on the belt.

And Sole usually prides itself in using very large rollers.

Overall though, I think the fact that the ST90 comes with an AC motor is pretty spectacular, given the price.

With an AC motor, this treadmill is capable of running smoothly for longer durations, making it a great choice for long distance runners or homes with multiple users.

Features

The ST90 Treadmill comes with the following included features:

15.6″ touchscreen- the ST90 comes with a large, Android based touchscreen console, making it easy to select and view all workouts and entertainment options.

Entertainment apps- the large console comes pre-loaded with all the most popular entertainment apps, including Netflix, Hulu, Disney+, Prime, and more.

Sole+ – it’s also equipped with Sole+, Sole’s free streaming app that gives you unlimited access to instructor-led workouts (for free!)

Screen mirroring- you can plug your phone to the console and view anything on your phone through the large console screen (including competitor’s streaming services if you want to).

Free mode- this feature turns off the motor and essentially turns the ST90 into a manual treadmill, adding an extra level of difficulty to your workouts.

Rail controls- you can control both the speed and incline through the conveniently located controls on the side rails.

Bluetooth speakers- you can listen to your workout jams wirelessly through the built-in bluetooth speakers.

Wireless charging- you can also keep your phone/tablet charged via the wireless charging panel.

Heart rate monitoring- you can get an estimate of what your heart rate is with the built-in grip monitors or get a more accurate reading with a strap heart rate monitor (one not included).

Tablet holder- the tablet holder’s located above the console, so you don’t have to worry about blogging your view of it while watching your tablet.

Cooling fan- the built-in fan can help keep ya comfortable during strenuous workouts.

Water bottle holder- yup, there’s a place to store your beverage of choice too.

Assembly

If you decide to purchase the ST90, you won’t have to worry about the assembly process – it’s very straightforward.

The main deck comes preassembled, so you’d only be responsible for attaching 2 uprights, the middle section, the console, and the tablet holder.

Everything is simply bolted on.

You have to make sure not to pinch any console wires of course.

The only thing to keep in mind is how heavy this treadmill is – remember, this thing weighs almost 400 lb, so moving it to its desired location might be harder than assembling it.

It’s also a good idea to have a second person available for when it comes time to attach that middle section (the part that holds the console).

Overall though, assembly should be pretty easy. Sole also offers white glove installation for those who don’t want to mess with assembly.

Warranty

Sole backs their ST90 with the following residential warranty:

• 5 year frame
• 5 year motor
• 3 year deck/parts
• 1 year labor

Sole’s warranty on this treadmill isn’t quite as generous as some of their other guarantees and I’m not sure why.

5 years on the frame and motor is actually pretty short for a treadmill in this price range, especially considering Sole offers lifetime frame/motor warranties for all their other models.

A year on labor is pretty standard for any treadmill, so no issues there.

Overall, I’m not sure why Sole doesn’t back the ST90 with their standard warranty, but this is the biggest downside I see.

Sole’s ST90 vs The Competition

	Sole ST90	Peloton Tread+	NordicTrack Commercial X32i
Running Surface	20″ x 60″ Slat belt	20″ x 67″ Slat belt	22″ x 65″ Traditional belt
Motor	2.0 HP AC	2.0 HP AC	4.25 CHP DC
Speed/Incline	0.5 – 12 mph 0 – 15%	0.1 – 12.5 mph 0 – 15%	0.5 – 12 mph -6 – 40%
Rollers	7.44″	?	2.5″
Console	15.6″ touchscreen	32″ HD touchscreen	32″ HD touchscreen
Warranty	5 year frame/motor 3 year parts 1 year labor	5 year frame/motor 1 year parts 1 year labor	10 year frame 2 year parts 1 year labor
Price	~$4000	~$6000	~$4500

Ok, so it wasn’t easy to come up with comps for the ST90 because there aren’t that many slat belt treadmills in this price range.

The Woodway treadmills mentioned earlier are amazing slat belt machines, but they’re not really priced for home use (and you’ll have to spend at least $10k to get one of their commercial models).

So, I went ahead and chose Peloton’s Tread+ and NordicTrack’s Commercial X32i because they’re in similar price ranges and the Tread+ is a slat belt model.

You can see the specifics in the table above, but the Tread+ comes with the same strength AC motor and an even shorter warranty.

And it obviously costs quite a bit more than the ST90.

The X32i isn’t a slat belt treadmill, but it’s priced similarly and has some other great features.

It’s a huge treadmill, known mostly for it’s jumbo HD touchscreen and insane inclining capabilities (40% is just madness), but it’s a quality machine.

If nothing else, I hope this table shows that the ST90 is pretty unique in the fact that it comes with a slat belt and an AC motor for this price range.

Sole’s ST90 vs Sole’s F89

The F89 is Sole’s second most expensive treadmill, so I thought it would be fun to compare these 2 machines to see how they stack up.

	Sole’s ST90	Sole’s F89
Running Surface	20″ x 60″ Slat belt	22″ x 60″ Traditional belt
Motor	2.0 HP AC	4.0 HP DC
Speed/Incline	0.5 – 12 mph 0 – 15%	0.5 – 12 mph -6 – 15%
Rollers	7.44″	2.75″
Console	15.6″ touchscreen	21.5″ touchscreen
Warranty	5 year frame/motor 3 year parts 1 year labor	Lifetime frame/motor 3 year parts 1 year labor
Price	~$4000	~$3000

The biggest difference is that the F89 comes with a traditional belt and a 4.0 HP DC motor, but the F89 also comes with a better warranty.

And of course, the F89 also costs about a grand less.

Folks who like the ST90’s console, but don’t necessarily need the long-running AC motor, might want to consider the F89 because it’s a great combination of performance and features.

And both of these treadmills come with the same console and all the same streaming options.

Full disclosure though, it’s highly popular and is prone to selling out…

Final Thoughts

Ok, that about does it for the ST90.

As I mentioned in the intro, I think this treadmill has a lot going for it.

The slat belt is a huge perk, but for me this treadmill’s most redeeming feature is that AC motor – and there aren’t many treadmills in the $4000 price range that come with both.

It’s also awesome how heavy-duty this thing is.

The biggest downside I see (and I can’t believe I’m saying this about a Sole treadmill) is that the warranty could be longer.

Something else worth noting is that this treadmill doesn’t fold, so you have to make sure you have enough dedicated floor space.

Overall, I think the ST90 would make a great choice for a serious runner or a home where multiple folks would be using it on a regular basis, but I could also see it making sense for folks looking for a lower-impact belt.

If you don’t plan on running long distances at a time or will be the only user in your home, you may want to save some cash and go with one of Sole’s more affordable models.

Either way, I do commend Sole for creating such a high-end, comfortable treadmill.