Although there are many different cycling brands to select from, many still believe the Keiser M3i is the golden standard for rear-flywheel cycling bikes. This model, introduced in 2006, is still widely used in homes and fitness facilities.
As an indoor cycling instructor, I have learned various models exceptionally well throughout my career based on the equipment that my facility (The Ridge Athletic – Montana) has decided to use. Over the past year, I have ridden the Keiser M3i for all my cycling classes. Here is what I have learned from the hours spent in the saddle on this model.
My Verdict & Pros/ Cons
A top-tier, rear-flywheel indoor bike known for its quiet, smooth, and adjustable ride. Its self-powered design doesn’t need electricity, adding convenience. The M3i’s robust build and reliable performance make it a favorite among serious cyclists and fitness enthusiasts.
I was excited when I first learned that the M3i would be the model I got to ride for class. I had read quite a bit about this bike but had never actually been on one. Like any new bike, I always feel that there is a learning curve to finding the best set-up. It took me a few classes since it has a V-shaped frame, and I always find it a little harder to find the sweet spot where my knees feel great, and I do not have saddle soreness.
Keiser M3i Model Options
Keiser has continued to create additional M3i models, offering customers and cycling studios a wider variety of options to find the model that suits their needs. See how these models compare below.
| M3i | M3i Studio | M3i Studio+ | |
| Price | $2,985 | $3,320 | $3,490 |
| Height Range | 4’10″ – 7’ | 5’ – 6’2” | 4’10″ – 7’ |
| Console Type | M Connect | Studio Display | Studio Display |
| Gears | 24 | 72 | 72 |
| Model # | 5507 | 5508 | 5509 |
| Handlebar Adjustability | 4-way | 2-way | 4-way |
How We Rated the Bike
Our team at Indoor Cycling Love rates each piece of equipment against eight categories, when applicable, to help our readers decide which models best suit their needs. Please see below what categories we use in which bikes receive a score of up to five.
Rating System Categories
- Construction Quality & Durability
- Assembly Process
- Comfort & Adjustability
- Connectivity
- Support, Financing Options & Warranty
- Value for Money
First Impression
Main Specs & Features of the Spin Bike
- Flywheel weight: 8 pounds
- User height range: 4’10” -7′
- Resistance levels: 22
- Height: 45″, Width: 26″, Length: 49″
- Item weight: 85 pounds
- Max user weight: 300 pounds
Main Bike Parts Overview
Detailed Review
Riding Experience & Performance: 4.5 / 5.0
The M3i offers a smooth and silent riding experience. The pedal strokes are seamless, with no disruptions throughout the rotations, even though the flywheel only weighs eight pounds. This Keiser model includes 24 gears of magnetic resistance, which is different from models like the Peloton or Bowflex C6, which feature 100 levels of magnetic resistance. While the Keiser M3i doesn’t include these micro resistance adjustments, the resistance gear levels are challenging.
Since this model includes hybrid pedals, you can ride in regular sneakers with toe cages or click in with an SPD cleat.
My Tip: Remember that if you are purchasing cycling shoes for the first time and only plan to ride inside, ensure that you select a model with a hard, smooth bottom instead of tread. I have found that some shoes made for riding outside have trouble clicking into a hybrid pedal since it is not like the typical SPD pedals that people place on their outdoor bikes.
Unlike many models, including the Bowflex C6 and the Peloton that use a resistance knob to adjust resistance levels, the M3i uses gears instead. This model has 24 gears available, unlike others that have 100 levels. The difference in resistance levels means that you can feel a more significant resistance change as you add gear. Compared to the micro-adjustments of a model with more resistance levels. Don’t let this model only having 24 gears fool you, those higher gear levels are challenging.
Construction Quality & Durability 4.8 / 5.0
The M3i has fantastic construction quality and durability. The most common issue I find with this model is that the seat can loosen over time and begin to tip down. The seat issue is an easy fix; just a little tightening will place the seat in the correct position.
Depending on when the version of the M3i, some of these bikes have a pin design that secures the seat post in place, but older versions of the M3i do not have a pin but just a tension knob that secures the seat post. With the versions that do not have a pin, the seat post can become stuck in the bottom position if it slams to the bottom of the seat position and is not carefully lowered. When this happens to one of my students, I always have to move them to a different bike and have maintenance come and fix it, as I cannot unjam the seat post.
Remember that the bikes in a studio are used much more frequently than someone who will have a bike at home. Only a few riders are taking 3-4 rides per day on their home model, so these limited issues should not be prevalent and should not keep you from purchasing this model.
Comfort & Adjustability 4.5 / 5.0
The handlebars and saddle offer four-way adjustability and can, therefore, accommodate a wide range of riders. Since this model has a V-shaped frame, it is important to note that as the handlebars are moved higher, they do get farther away from the saddle, which can be bothersome for smaller riders who prefer to ride with higher handlebars, those with back issues, or those who are pregnant and require the handlebars to be in a higher position.
While some people enjoy the handlebars, I prefer a more traditional handlebar style that allows riders to rest their hands comfortably in position one.
I appreciate that there is only one stabilizer that will stabilize the entire bike instead of having to adjust four different touchpoints under the bike’s feet.
My Tip: While there are many versions of the M3i, I recommend purchasing a version with a pin and holes in the seat post for a more secure position instead of the smooth seat post version that is also available.
One of the most minor adjustability options, but one of the coolest I found, is that the tablet tray is removable. This piece of the bike is usually securely attached and unable to move, but I like that Keiser gives riders the option to have it on the handlebars or not.
Connectivity 4.8 / 5.0
The M3i offers wireless heart rate monitor connectivity. Keiser suggests pairing it with a Polar 9 or 10 monitor. The newer models also include ANT+ and Bluetooth connectivity, but the model I have ridden in class for the past year does not.
More connectivity options are available through the use of the M Connect. The upgraded M Console, that my facility currently does not have, includes the M Connect technology within the console instead of requiring the older M Connect technology.
If you have the correct console or the M Connect, the M3i can be used with various apps. Some apps it integrates include FulGaz, TrainerRoad, Rouvy, Peloton, and Zwift. It does not pair with Strava.
The Keiser M Series App is available for iPhone and Android. It is free and can provide real-time graphs for power, FTP zones, cadence range dials, and W/Kg ratios as long as the bike has the correct console.
Support, Financing Options & Warranty 4.5 / 5.0
I do not have any personal experience with their support team, as our in-house bike tech at my fitness facility handles any bike issues. The M3i offers a 3-year all-inclusive warranty. Most warranties include a 10-year warranty for the frame and a 1-year warranty for parts and labor.
Value for Money 4.2 / 5.0
While this bike is excellent, many provide a similar riding experience at a more palatable price tag. For someone closer to my height, I feel that there are other models that are more affordable and provide a better fit, but it might be worth it to those above 6’5” as not many bikes accommodate this height range.
While these bikes are at a higher price point, I have found they have fewer issues than some of the less expensive models on the market.
Comparison with Alternatives
Bowflex C6
The Bowflex C6 offers an excellent riding experience at a fraction of the cost of many other commercial-grade indoor cycling bikes on the market. Priced at under $1,000 and allowing the opportunity to pair with many of the industry’s popular cycling apps, including Peloton and Strava, this is one of the reasons I have kept this model as my home bike for over 4 years.
BODi MYX II
The BODi bike offers a unique riding experience as it features traditional friction resistance compared to the industry’s new golden standard of magnetic resistance. I enjoyed testing this bike and experiencing its integration with all the Beachbody classes and BODcast features. This feature allows riders to join instructor-led classes and be seen in real-time, which is unique to all other platforms. Due to the monitor, the handlebars do not offer 4-way adjustability.
Freebeat Lit
For riders looking for a more game-like riding experience, Freebeat offers a point-based workout where riders can earn prizes for workouts and streaks. I enjoyed testing this model as it focuses on riding to the music rhythm. Many of the games reminded me of playing Guitar Hero. The large monitor connects to the Freebeat platform only. This bike does not include hybrid pedals but toe cages only. Like the BODi bike, the handlebars do not offer 4-way adjustability due to the monitor on this model either.
FAQ
- Is the Keiser M3i accurate?
Yes, the Keiser M3i is accurate and remains the gold standard for a magnetic resistance bike. It received an EN957-10 certification for power accuracy.
- Is Keiser M3i a smart bike?
It depends on which M3i model you are referring to. The original M3i does not have Bluetooth capabilities, while the Plus model integrates with many platforms via an ANT+ and Bluetooth.
- What heart rate monitors work with Keiser m3i?
Keiser recommends Polar heart rate monitors and emphasizes a H9 or H10 for the M3i.
Bottom Line
A top-tier, rear-flywheel indoor bike known for its quiet, smooth, and adjustable ride. Its self-powered design doesn’t need electricity, adding convenience. The M3i’s robust build and reliable performance make it a favorite among serious cyclists and fitness enthusiasts.
The Keiser M3i is a quality bike that initially set many industry standards for a rear-flywheel model. However, many other bikes are similar or offer new features on the market. It is exceptionally well built and has maintenance issues less frequently than others I have ridden, and when it does have problems, they are minimal.
Through my classes, I have seen this bike accommodate a wide range of riders, but that is not enough to stop my current facility from considering other models for when they upgrade their studio in the near future.
| Great For | Not Recommended For |
|---|---|
| – People 6’5” and up – Riders up to 350 pounds – Purchasers looking for a bike that is made to last – Studios or home use | – Those on a tighter budget – Those that prefer a knob resistance system over gears |
In truth, this Bike hasn’t changed much in over 17 years (since m3 in ~2007) it’s that good!, 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 spinners on a budget just buy a used keiser m3i with the original computer – there’s always the ‘K2pi converter’ (instead of keiser magic box) which gives you all the benefits of the newer computers – eg more compatible Bluetooth for apps like Zwift and peloton along with Ant ! Perfect for connecting to multi sport watches like Garmin at same time as using Bluetooth 👏👍
Thank you for your insightful comment!
I really like the smooth motion, almost no maintenance effort and the power meter. However I found the minimum resistance for me to ride in control is 10. I am not a heavy rider so I can’t take advantage of body weight to push the pedal. Is Keiser m3i suitable for me or I am just a poor rider???