CAROL Bike Review 2024 | TreadmillReviewGuru.com

In-depth CAROL Bike Review: Testing & Analysis

Dimensions/Storability

The CAROL Bike looks like your typical indoor cycling bike.

The build of the bike is standard, but it’s the features that make it unique. For your home or studio gym – wherever you plan on using this bike – you’ll need to make sure you have enough floor space. Like other popular exercise bikes, the CAROL 2.0 is smaller than a treadmill and doesn’t require a high ceiling to use. Its dimensions are 45.5” long and 22” wide. You’ll need to factor in these dimensions, plus, give yourself a little bit of extra space on the sides of the bike for getting on and off and pedaling.

The CAROL Bike weighs 120 lbs. This isn’t the heaviest indoor cycling bike we’ve tested, the NordicTrack S22i and S27i are pretty heavy at over 200 lbs each when delivered, but the CAROL isn’t the easiest to move around. There are two transport wheels at the rear of the bike under the flywheel. It makes sense that they’re here because this is where the majority of the weight of the bike is, but it’s hard to move.

To move it, you have to lift the front stabilizer under the handles.

This engages the rear wheels. It would be helpful if there was a handle to grab. The easiest way to move it is by squatting down and lifting the front, you have to watch out for the handlebars to not hit your head though. Just keep this in mind. We have found other bikes with front-weighted flywheels are easier to move with transport wheels on the front.

Onboard Workouts & Apps

The CAROL Bike’s membership is different than other onboard workouts and training apps that we’ve used. The attached tablet includes subscription training content, as well as other 3rd-party apps. It also includes AI technology.

Here is what to expect from CAROL’s membership.

CAROL Membership

The CAROL membership, standing for “cardiovascular optimization logic”, is $19.99 per month for home memberships and $49 per month for commercial memberships. Commercial memberships give access to 24 rider profiles and the home membership allows for up to 8 profiles.

The CAROL Bike and membership are designed around REHIT workouts. REHIT means reduced exertion high-intensity interval training. REHIT is a version of HIIT workouts – high-intensity interval training. HIIT workouts involve doing short and intense bursts of activity to get your heart rate up. These workouts can vary in length but are usually at least 20 minutes long. REHIT is the idea that you only need to complete 2 or 3 10-20 second sprints separated by a few minutes of very low-intensity exercise to get the same results as longer exercise sessions.

The CAROL membership includes 20 different workout options.

These are split into different categories: REHIT, Fat Burn, Free & Custom, and Fitness Tests.

The REHIT workouts are the most time-efficient. They range from 4:40 to 11:45 minutes long. There are 5 different options:

Intense: 2×20 second sprints
Intermediate: 3×15 second sprints
Intermediate: 2×15 second sprints
Energizer: 3×10 second sprints
Energizer: 2×10 second sprints

Each workout starts with a very low-intensity warm-up, rest periods between each sprint interval, and a cool down. All of the low-intensity portions are meant to be done with no resistance and slow pedaling. Each sprint interval is for going all out and pushing yourself to the max.

What makes the CAROL Bike and the membership what it is, is the REHIT workouts and AI-generated resistance. The bike doesn’t have a resistance knob (more on this later), instead, the resistance is adjusted automatically with AI to tailor it to you.

When you first start the membership, you’re required to take 3 REHIT workouts before unlocking the rest of the workouts.

During these, the AI feature assesses how much resistance you need while sprinting to keep you at your max intensity during the sprint intervals, and while resting, which is when the bike takes off the resistance completely.

These workouts and the CAROL Bike are customizable to you and your fitness level. REHIT workouts are scientifically proven to be more effective at improving your cardiovascular fitness than longer cardio workouts. The short bursts of cardio deplete your muscle glycogen (emergency energy reserves) triggering your body to produce more mitochondria and increase your blood volume. By digging into your body’s emergency energy reserve, your body must adapt to the stress by strengthening your cardiovascular system. It also gives an “afterburn” effect where your body burns more calories after you workout.

This makes the CAROL Bike a great option if you’re short on time. With this bike, there’s no excuse because you can literally hop on for 5 minutes 3 times per week and still see results. I think the REHIT workouts are also less intimidating than other workouts, like HIIT training, since they only involve a couple of sprints for 10-20 seconds at a time.

The Fat Burn workouts are longer and more intense.

They’re still time-efficient because they range from 10 to 25 minutes. These are HIIT workouts that let you choose between 30, 45, and 60 8-second sprints with 12 seconds of rest between each. Doing 30 all-out sprints for 8 seconds at a time and only getting 12 seconds to recover, is tough. The Fat Burn workouts are meant to burn twice as many calories as moderate exercise. CAROL recommends these if weight loss is your goal.

If you’re thinking these are too intense for you, you can skip some of the sprints. At the beginning of the intervals, a prompt on the screen says to skip some of the sprints, if you need to.

The Free & Custom setting allows you to just ride or do targeted training.

The Regular Free Ride lets you control the resistance of the bike on the touchscreen. You can ride for as long and as hard as you want like you would on a typical indoor cycling bike. The target rides let you choose specific heart rate training zones and power (watts) targets.

The Free & Custom setting also has different sprint intervals you can take that are more challenging than CAROL’s main REHIT workouts.

The Fitness Tests test your VO2 max, functional threshold power, and maximum aerobic power. These are used to calculate your fitness score. CAROL is constantly assessing your efforts to appropriately adjust the resistance of the bike during the sprints and to give you a fitness score. You can see how your fitness score ranks compared to other members, too.

Combining all of these workout options makes the CAROL Bike versatile and a great option for most people from beginners up to advanced athletes. The amount of science behind the workouts and the data that the CAROL Bike remembers from each ride is beneficial and impressive. So, if you’re short on time, want intense workouts, or want to do popular zone 2 training, there are plenty of structured workouts on the CAROL Bike. Zone 2 training is keeping your heart rate at 60-70% of your max.

The format of each of the workouts is simple, yet engaging. The screen features 3 different meters for your power (watts), cadence (RPMs), and heart rate (BPMs). There is text that pops up during most of the workouts to provide extra guidance and motivation. I like that it encourages you to take deep breaths during the rest portions of the REHIT workouts.

Along with all of this, you can download certain training and streaming apps directly to the tablet. These include apps like Netflix, Prime Video, Disney+, CNN, YouTube, Zwift, Peloton, FulGaz, and ROUVY.

There are only specific apps available to download onto the CAROL’s tablet, but downloading them directly means you can stream directly from the bike.

Also, when training using apps like Peloton, you can adjust your resistance by 100 different levels just like the Peloton Bikes, as well as see your metrics right on the screen when riding in the trainer-led classes. Some of the other training apps more targeted at outdoor riding let you change the resistance of the bike in gears like you would an outdoor cycling bike. This is a really cool integration.

Onboard Workouts

The CAROL Bike can be used without CAROL’s membership. All of the downloaded apps like Netflix and Peloton are available without a subscription. You can also take some of the workouts, and of course, do your own thing in the free ride mode. For the REHIT workouts available without CAROL’s membership, the AI-generated resistance stays at an average level, rather than the level that works for you. You only get the customization to you and your fitness level when you subscribe to the membership.

Console

The console consists of an 11” tablet that’s mounted on the front of the bike. It is fixed to a holder and connected to the bike to adjust the resistance against the flywheel with the AI technology and from the screen when you adjust it manually. The tablet can be turned on when the bike is unplugged, and it charges when the bike is plugged in.

Note: You must plug in the CAROL Bike to use it. You also need to have the tablet on and in a workout to use the bike. The CAROL Bike isn’t meant to be pedaled when a workout isn’t in progress on the screen.

I like that the CAROL Bike has an attached tablet.

This allows you to be able to download compatible apps onto it and stream content outside of CAROL’s membership. The tablet tilts up and down but doesn’t detach from the bike.

It’s really easy to see and reach. The speakers are also clear to listen to the streaming content and/or music available in CAROL’s workouts. Streaming from apps like Netflix and Amazon Prime is a big draw, but I actually liked listening to the music CAROL provides. It is different than typical stations of songs.

There isn’t a resistance knob or brake on the CAROL Bike 2.0. The resistance is either AI-generated or adjustable on the screen. It is easy to adjust on the screen in certain workout settings and the 3rd-party training apps.

There isn’t any storage besides the 2 small cupholders that are attached to the handlebars.

These are a little small for my Stanley Cup, but they hold a standard water bottle just fine. I like that they’re on the handles, rather than down in front of the saddle. It’s easier to reach my water and I don’t have to worry about hitting my water with my foot when getting on and off the CAROL Bike. There isn’t an included device rack for your phone or tablet. This keeps you locked into the touch screen and training content if you subscribe to CAROL.

For heart rate tracking, the CAROL Bike 2.0 comes with a chest strap and compatible heart rate monitors through Bluetooth.

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Build Quality

The CAROL Bike 2.0 is rated for commercial use. This means that it can handle heavy use throughout the day. It is found in studio gyms and homes. Although it is pricy for home use, its quality and training features make it great for users who have the budget. At the time of writing this, the CAROL Bike is about $2600.

This exercise bike has a nice steel design and features.

It handles people up to 330 lbs. 350 is the highest weight limit we usually see on exercise bikes. The CAROL Bike should handle people up to its limit.

Frame

The steel frame is powder-coated to help prevent corrosion. The black and silver design is pretty sleek and overall the frame and build feel high-end. Plastic pieces cover the drive train, but the steel floor stabilizers, seat and handlebar posts, and rear flywheel make the CAROL Bike very solid and stable to ride.

Along with these components, there are 4 adjustable leveling feet under the stabilizers. This allows the CAROL Bike to be planted on the floor, even if that floor is a little uneven.

Like most exercise bikes with attached screens, the CAROL has 3 adjustment points. The saddle can be positioned up/down and forward/back. The handles can adjust up and down, too. They don’t move forward and backward, but with the amount that the seat adjusts, most people should get a good bike fit.

CAROL says this bike works for users from 4’7” up to 6’7”.

The tall height limit seems appropriate. Matt, who is 6’5”, doesn’t need to raise the saddle to its highest setting, so people a little taller than him should fit. I am 5’1”, and I am on level 3 for the saddle. I think 4’7” might be a stretch, but certainly, people a few inches shorter than me should fit on the CAROL 2.0.

To give you an idea of how the CAROL Bike will work for you, I measured the leg span and reach from the lowest to the highest saddle adjustments. The leg span, measured from the top of the saddle to the top of the lowest pedal ranged from 29”-39”. This is your inseam length.

The reach, measured from the nose of the saddle to the base of the handlebars when the saddle was all the way forward and backward ranged from 11”-16”. This 5” range of adjustability makes up for the handlebars not adjusting forward and backward.

Flywheel

The rear flywheel has a steel core with brushed aluminum on the outside. It is 22 lbs making it a heavily-weighted flywheel. This isn’t the heaviest flywheel we’ve used, but it is a good weight that makes for a smooth, consistent, and stable ride.

The rear placement is good for the longevity of the bike.

It is placed out of the “sweat-zone”, which you’ll inevitably do, even during the short REHIT workouts. Being placed at the back helps prevent damage to the flywheel from your sweat and water, assuming you’re staying hydrated while riding.

The rear flywheel and v-shaped frame remind me of the Keiser Bike.

The Keiser Bike has a light flywheel though, and since it doesn’t have AI resistance capabilities, it feels different to pedal. However, when you adjust the CAROL Bike’s resistance yourself, it feels more like a typical indoor cycling bike.

One aspect that can take some getting used to, is the light resistance in the REHIT rides. The AI technology removes all of the resistance and encourages you to work at a very low intensity. This makes the pedal stroke feel very light and inconsistent to pedal at times. Since there isn’t any tension, you don’t get the same feeling of pushing down and pulling up through each pedal stroke that you do on other bikes at light resistance levels.

This isn’t a bad thing, but it can take a little getting used to, especially if you’re a spin class junkie. I think we can get programmed to go all out when hopping on indoor cycling bikes, but the CAROL Bike isn’t meant to go all out all the time.

Another aspect of the resistance and pedal stroke is that you have to have enough resistance on the bike to stand up out of the saddle. This is true on other bikes. Without enough resistance, you can’t sink the majority of your weight into your lower body to balance and pedal.

When using the AI-generated resistance, you might not want to stand out of the saddle or be able to. You could potentially stand during the sprint portions of the REHIT workouts, but I was most comfortable sitting during those. The only time I got out of the saddle was when I was adjusting the resistance myself. This way, I could adjust the appropriate amount of tension I needed to comfortably stand.

Drive System

What connects the pedals to the flywheel is a poly-v belt that is under the plastic covers shown here.

This makes the CAROL Bike 2.0 practically silent. You can hear the resistance when it is adjusting, but it’s really quiet. The belt self-tightens so you don’t have to worry about tightening it and it shouldn’t require much (if any) maintenance.

Instead of a friction brake, the CAROL Bike has a freewheel safety clutch. This works to allow you to stop the pedals while the flywheel is still moving. Other bikes that have brakes and weighted flywheels, require you to press a brake knob to stop the flywheel if you stop pedaling abruptly. This is necessary if your foot comes off of a pedal and if you get pedaling too fast with light resistance and the weight and momentum of the flywheel keep going, requiring you to press a brake.

These brakes work by pressing a felt pad against the flywheel to stop it from moving. This can create wear and tear on the flywheel. Instead, the CAROL Bike’s freewheel safety clutch and friction-free magnetic resistance don’t place stress on the flywheel. The safety clutch just provides a mechanism to prevent the pedals from continuing to move with the flywheel after you stop pedaling. It provides safety and gives you control of the bike.

The pedals are hybrid with SPD clips on one side and toe cages on the other. This is really the best option for pedals because it gives you the choice between wearing regular tennis shoes and clipping in cleats. This allows more people to comfortably ride the CAROL Bike.

Handlebars & Saddle

The handlebars and saddle are also comfortable. The handlebars have a good width for taller users and they offer plenty of grip options. I like the middle center handle. It is wide for comfortable handle placement in the second position. The handlebars are fairly thick, but I can wrap my hands around them.

They also have a grippy texture so your hands don’t slip.

I like the saddle.

It has a little bit more padding than other exercise bikes, like NordicTrack’s and Peloton’s. It is still narrow for distance riding though.

Warranty

CAROL includes a 5-year frame, 1-year components/parts, and a 1-year labor warranty with the purchase of the CAROL Bike. We like to see at least 10-year warranties for the frame, especially on pricier bikes, like this one. Having 2 people for setup is a good idea, but one person who is comfortable with putting together equipment could probably set it up just fine.

Should You Buy The CAROL Bike?

The CAROL Bike puts a unique spin on indoor cycling. It isn’t your average spin bike, it’s something more. The CAROL Bike is designed to get the most out of your workouts in the least amount of time possible. The REHIT workouts are the brand’s staple workouts requiring you to complete only 2-3 10, 15, or 20-second all-out sprints with low-intensity pedaling in between.

Even if you only have 5 minutes, the CAROL Bike makes it so you can’t skip your workouts. I know most of us are busy, but we have 5 minutes. The CAROL Bike automatically adjusts the magnetic resistance with AI technology. It adjusts it based on your prior performance so when you complete the REHIT sprints, the bike pushes you to your max.

The CAROL Bike also works as a regular indoor cycling bike. Some of the workouts allow you to adjust the resistance on the screen, rather than with a knob. Plus, this bike is rated for commercial use so it’s very high quality. It is pricy at around $2600, so it isn’t for everyone and it’s definitely not a budget pick, but it incorporates scientifically-proven workouts that are designed to get you “fitter faster”.

The CAROL Bike is great for beginners up to advanced athletes and everyone in between because of its versatility. It’s a no-excuses machine to improve your cardio fitness, without wasting any time.

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CAROL Bike Review FAQs / Q&As

Is CAROL Bike worth it?

The CAROL Bike is worth it if you have the budget and are short on time. It is also an excellent option if you want to get the most out of your cardio machine. With proven, time-efficient workouts, the CAROL Bike can help you increase your fitness in less time. If you have just 5 minutes, the CAROL Bike can work for you. It also is versatile to use for longer rides.

Can you use the CAROL Bike without a subscription?

Yes. There are workouts available as well as the free ride mode, without a subscription. During the available REHIT rides, the AI resistance adjusts to an average setting rather than a setting that is tailored to you. You can also access the downloadable apps on the tablet like Netflix and Amazon Prime, without a subscription.

Is this CAROL Bike review a paid review?

This CAROL Bike 2.0 review isn’t paid. CAROL sent us the bike, but they did not pay us to create this review. We work with all kinds of exercise bike brands to test all of the latest models. We get paid through our affiliate links. If you purchase through one of our links, we receive a commission. This allows us to test equipment, compile reviews, and recommend the best exercise bikes from our direct experience using equipment.

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About the Author

Sydney Kaiser, ISSA-CPT, ISSA Nutritionist Certification
Sydney is a certified fitness instructor, personal trainer, and sports nutritionist who combines her passion for fitness, health, and wellness with her passion for writing. After graduating from UC Riverside with a Master of Fine Arts in Creative Writing, she began teaching indoor cycling and Lagree Fitness group fitness classes to people of all ages and abilities. Raised in Central Michigan, Sydney grew up training and competing on the Arabian Horse Association circuit through both Regional and National levels in Dressage and Sport Horse classes. In college, Sydney went on to compete at the collegiate level as a Division 1 equestrian athlete. Here at TRG, Sydney relies on her extensive background in fitness when reviewing and recommending all kinds of fitness, recovery, and health-related products.

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