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Keiser M3i Indoor Cycling Bike Review

By Fitnosia Team – Last Updated: December 2021

Keiser M3i Review

Keiser M3i Overview

The Keiser M3i indoor bike is a unique-looking exercise bike. Despite the appearance of being sleek, this is a very well-made and sturdy exercise bike for those that are serious about their indoor cycling workouts. The Keiser M3i may be expensive, coming in at around $2,000, but this is the top-of-the-range exercise bike from Keiser, and it certainly has a lot going for it. Due to the design and engineering that has gone into the transmission, this is one of the most silent indoor exercise bikes that you can get.

Throughout this Keiser M3i review, we will look into a bit more detail about each feature and see how if the price tag on this exercise bike is justified. The Keiser M3i Indoor bike is one of the few indoor bikes that is made in the US. You get a 3-year warranty on the frame (6 months on wearable parts) and US-based customer service. This is a performance-orientated indoor exercise bike that will help you to get fit and have some fun while you are at it. Now let’s look at the details of the Keiser M3i in a bit more detail.

Bike Monitor

The bike monitor on the Keiser M3i spin bike is quite underwhelming. It provides you with all the basic fitness metrics you need, including the Gear, RPM, Watts, Calories, Time, and Distance. If you have an HR strap synced up, it also shows your HR. The Keiser M3i exercise bike has a direct power meter built-in, giving you accurate feedback on the power you are putting into the pedals.

The monitor is backlit; however, it sometimes seems slightly dim, especially compared to the more comprehensive displays on other exercise bikes in this price range. The screen is supposed to adjust the brightness when it senses low light conditions automatically, but it is not very easy to read in bright light.


The Keiser M3i comes with Bluetooth. However, many customers have been frustrated by the lack of compatibility with well-known cycling apps and hardware. Firstly, the Keiser M3i will seamlessly connect to the Keiser M Series app, which is adequate as a workout companion but lacks many features and shared experiences of apps such as Zwift and Peleton.

To make the most of other 3rd party cycling and fitness apps, you will need to purchase an M series convertor from Keiser (but at around $200, this seems like an expensive compromise). The ANT+ is similarly restricted. If you want to connect an HR monitor, you will need to stick with the Polar brand (included in the Keiser M3i Indoor Cycle Bundle). Note that the New Keiser M3i bike comes with an upgraded monitor that seamlessly connect with all major indoor cycling applications including Zwift and Peloton.

Power Source

Unlike many of the other exercise bikes at this price range, the Keiser M3i is not self-powered. You will need 2 x AA batteries for the small display. Due to the relatively limited features, the battery life is good, and at least you do not have to worry about setting up your indoor bike near a power outlet (recommended to replace annually).


The resistance and transmission system sets the Keiser M3i among the best exercise bikes on the market. It has a magnetic resistance system and provides one of the most silent riding experiences of all the exercise bikes available. The gearing is provided by a lever system (as opposed to the traditional knob). You can choose from ‘gears’ 1-24. The resistance levels have a wide enough range to maintain a high cadence or challenge yourself with really high gear.


As indicated above, the transmission is what has made the Keiser M3i so popular with indoor cyclists. It comes with a Poly-v belt that is super low maintenance and a lot quieter than chain transmission systems. The innovative transmission design with the flywheel at the rear of the bike provides an incredibly smooth riding experience. As soon as you start pedaling, the resistance is engaged, and it feels very similar to riding a traditional bicycle.

Flywheel Weight

Weighing in at 8lbs, the Keiser M3is flywheel is a lot lighter than many other exercise bikes. However, somewhat counterintuitively, it provides a much smoother riding experience than a lot of those indoor spin bikes with heavy flywheels. The flywheel is located at the back of the bike, keeping it protected from your sweat. Although it does come with a guard around the perimeter, the flywheel’s sides are exposed. So it is essential not to have small children running around while you are on the bike.

Q-Factor Size

Many performance-oriented indoor exercise bikes have a very narrow q-factor, due in part to the improved pedaling efficiency and similarities to the feeling of riding a road bike. Interestingly Keiser has decided to go for a much broader q-factor of 197mm compared to most of their competitors in the price range (155mm – 170mm).

Pedals and Cranks

This is an interesting move. It means that the Keiser M3i is more geared to the average person than the narrow-waisted professional cyclist. A wide q-factor is more comfortable if you have wider hips or naturally cycle with your knees further apart from the frame.

The Keiser M3i comes with dual-sided spinning pedals. On the one side, you have an adjustable toe clip. On the other the fitting for SPD cleats. Even if you are new to cycling, it is worth purchasing some indoor cycling shoes with SPD cleats to make the most of your workouts and use all the muscles in your leg with every pedal stroke.

Specifications and Adjustability

The Keiser M3i is incredibly sturdy despite its relatively basic and minimalistic design. There is little to no wiggle or wobble, even when you are standing up and pedaling hard. The stabilizer feet do their job well and can be adjusted if you use them on a slightly uneven surface. It also has a generous max rider weight of 350lbs, a testament to the steel v-shaped frame’s strength.

Both the seat and the handlebars are 4-way adjustable. This allows you to find the perfect riding position for you. You would be forgiven for thinking that the v-shaped design restricts the adjustability, but Keiser has combated that with the ability to move the seat and handlebars fore or aft. The handlebars’ relatively unique design also allows for several different hand positions to keep you comfortable, especially during longer workouts.


Although the Keiser M3i does not come with many accessories built-in, the Keiser M3i Indoor Cycle Bundle includes everything you need to start your indoor cycling adventure. The bundle consists of a floor mat, media tray, stretch pads, and Polar Heart Rate monitor. The media tray is a must, as to make the most of the Keiser M3i accurate power meter, you will want to track your workouts by connecting it up to a tablet or phone.

Due to the minimalistic design, there is nowhere to store any water bottles on the bike, so you will need to make sure you have some bottles within arm’s reach. You can also get a fitting to allow you to fit small weights below the seat (sold separately). As mentioned above, you will also need to buy a Bluetooth converter if you want to use the most popular cycling or fitness apps.

Keiser M3i Indoor Bike Pros:

  • Unique and minimalistic frame design keeps the weight and size of the Keiser M3i down
  • Very smooth and near-silent riding experience thanks to the revolutionary drivetrain and transmission
  • Very accurate power readings from the inbuilt direct power meter
  • Incredibly comfortable to ride thanks to all the adjustability and design of the handlebars
  • Relatively light compared to other indoor exercise bikes in this price range and easy to transport thanks to the transportation wheels on the front
  • US made and high overall build quality and stability while cycling

Keiser M3i Indoor Bike Cons:

  • This is an expensive indoor exercise bike. Especially when you consider that due to the minimalist design, you need to pay extra for many accessories
  • The seat is very similar to those found on a road bike (i.e. narrow and uncomfortable). You can get a gel-padded cover to take away some of the discomforts.
  • If you are paying this much money for the bike, it is a shame that you would need to pay an extra $200 for a device to allow you to connect the bike up to your favorite training app. The Keiser M-series app is adequate to track your workouts (and there is no monthly fee), but it does not have as many features as the more popular cycling and fitness apps in the market. Read more about Keiser M3i applications here.

The Final Verdict

This Keiser M3i review has taken into account all the main features and functions you should be thinking about when looking to invest in a top-of-the-range indoor exercise bike. The review shows that the design and transmission system on the Keiser M3i is equal parts unique and very effective. The near-silent and super smooth riding experience more than justify the relatively hefty price tag. However, the lack of built-in programs and data recording features does let the Keiser M3i exercise bike down. That said, you can spend an extra $200 and still be paying less than some other high-end exercise bikes.

If you are relatively new to cycling and are looking for a minimalist exercise bike that will help you work out more and not annoy the rest of your household while in use, then the Keiser M3i is the best indoor bike for you. The Keiser M3i is stable enough and has enough features to help experienced cyclists level up their fitness. It’s also the best spin bike for short and tall persons because of its adjustment and design. However, the large q-factor may feel unnatural for anyone that is used to riding a road bike.

Keiser M3i Indoor Bike
Keiser M3i review

The Keiser M3i is a groundbreaking entry into the indoor cycling and Spinning bikes market. The M3i is the first spin bike that is built 100% in the United States to ensure best quality. For studio spin classes, data from the M3i computer can be projected onto a display. With Keiser M Series, Zwift, and Peloton apps, riders can download data from the computer to their smart phone or tablet.

Product Brand: Keiser

Product Currency: USD

Product Price: 1800

Product In-Stock: InStock

Editor's Rating:


1 thought on “Keiser M3i Indoor Cycling Bike Review – Ride like an Elite”

  1. The Bike hasn’t changed much in over 17 years (since m3 in ~2007), computer has a seen a couple of upgrades in last couple of years, the last upgrade ‘studio display’ now even has a colour screen and costs an extra $1k!
    For keiser m3i users with the original computer there’s always the ‘K2pi converter’ which gives you everything the newer computers provides – eg more compatible Bluetooth for apps like Zwift and peloton along with Ant+! Perfect for connecting to multi sport watches like Garmin 👏👍


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Keiser M3i Spin Bike Rating

Keiser M3i Indoor Bike Review
Fitnosia Ratings:
  • Q-Factor: 197mm
  • Pedals: Dual-sided SPD & toe Cage
  • Flywheel: 8lbs
  • Resistance: Magnetic
  • Transmission: Poly-V belt
  • Weight capacity: 350 lbs
  • Height capacity: 4.10″ to 6.7″ (147 cm to 200 cm)
  • Bike weight: 84 lbs
  • Bike dimension: 26” W x 45” H x 49” L
  • Monitor: Backlit
  • Connectivity: Bluetooth and ANT+
  • RPM tracking: Yes
  • Speed tracking: Yes
  • Watt tracking: Direct
  • Applications: Keiser M-series app, Zwift, Peloton, Bkool. GOind, Spivi, and more.

Keiser M3i Alternative: Nordictrack S22i

Nordictrack S22i review

If you prefer more advanced indoor cycling with more features and integrated technology, NordicTrack S22i is the best Keiser M3i alternative. Unlike Keiser M3i, the S22i comes with a huge 22-inch touchscreen, speakers, and fan, plus an incline and decline system which I found really engaging and efficient. It helps you burn more calories and mimic the feel of the road. Plus, it is often cheaper than Keiser M3i indoor bike. I was lucky to get mine for $1499 which was $500 cheaper than Keiser M3i at the time.