Don’t let the minimalist design fool ya – Keiser’s M3 Indoor Bike is about as sophisticated as indoor cycles come.

Utilizing a fast spinning, lightweight flywheel, the M3 is able to keep its assembled weight down, making it easy to move around, without compromising on stability or function.

It’s also sportin’ one of the most accurate consoles on the market and was even the first indoor cycle to get recognized by the ISO for the accuracy of its metric reporting.

The M3 has also been renowned for its smooth operation and ability to closely simulate riding a road bike, but like any bike, it has its flaws too.

More specifically, the M3 doesn’t come with fully adjustable handlebars and its console is lacking some of the tech features we take for granted these days.

Long-story-short, if you’re looking for an elite cycle, the M3 is a good option, but before you decide on an investment of this caliber, you really need to know what you’re getting into.

And that’s where I can help.

In this review, I’ll go over all the specs, features, and pretty much everything else you should know about before deciding on this cycle.

After reading, you’ll know whether or not the M3 is the right bike for your home.

The Keiser M3 Indoor Bike

Keiser has made a name for themselves with their hi-tech, science based approach to fitness.

They’ve been around since the ’70’s and they initially came to fame with their pneumatic powered strength training machines, that’ve since become a popular choice for professional and Olympic athletes around the world.

Keiser came out with their M3 Series bike in the late ’90’s and the indoor cycling market has been forever chanced since.

Not only was Keiser the first brand to use eddy current magnetic resistance on a commercial cycling bike, but they were also the first to put the flywheel in the back (a design choice that’s been copied by a lot of other brands).

These days, Keiser doesn’t offer that many residential cardio machines to choose from – I think it’s more of a quality over quantity thing going on.

The M3 is actually 1 of only 2 cycles in their lineup, with the other being the upgraded M3i.

Pros

• Lightweight, fast spinning flywheel
• Sophisticated magnetic resistance system
• 24 gear levels
• Micro-adjustable resistance between gears
• Capable of providing a ton of resistance
• Rear-mounted design protects flywheel
• Fit’s riders 4’10” – 7′ tall
• Fully adjustable seat
• Dual-compatible pedals
• Polar H9 strap included
• Mat included
• Dumbbell holders included
• Good warranty

Cons

• Handlebars not fully adjustable
• Simple console
• No water bottle holder

Resistance

One of the biggest goals of any indoor cycle is to recreate the sensation of riding a road bike inside the safety and comfort of your home.

This is why these bikes were created in the first place (we have the famous Johhny G to thank for this).

Anyway, in order to do this, an indoor cycle needs to be able to provide a smooth pedaling motion, as well as provide enough resistance to recreate those hills cyclists encounter when riding outdoors.

This is done by pairing a spinning flywheel with either a friction brake or magnetic resistance system.

The M3 uses a magnetic system, so we can skip the friction brake stuff for now, but the key takeaway is that magnetic systems are better.

So, back to the flywheel.

You’ll see a lot of talk about indoor bikes and flywheel weights and the general consensus is that having a heavier flywheel is preferred because it provides a smoother pedaling motion.

The argument being that the heavier the flywheel is, the more momentum it’ll create as it spins, which in turn helps keep the pedals moving throughout each full pedal motion.

Which eliminates any lag between the upstroke and downstroke.

This argument makes a lot of sense and I agree with it 9 times out of 10, but it really only holds true for bikes that are designed to benefit from a heavy flywheel.

It probably didn’t take bike manufacturers that long to realize that adding more weight to the flywheel was an affordable way to give these bikes a smoother feel.

That’s why more affordable home exercise bikes design their resistances around heavy flywheels.

Well, turns out light flywheels can create just as much momentum (and even more) if they spin fast enough.

And this is the thinking behind Keiser’s lightweight flywheels (ICG also went this route with their famous cycles).

At just 8 lb, the flywheel on the M3 weighs a good 20 lb or so less than what most quality indoor cycles are using these days, but the M3 makes up for it by getting that flywheel spinning a lot faster than what these other bikes are capable of.

I believe the Keiser M3 has a gear ratio of 1:11, meaning the flywheel spins 11x for every full rotation of the pedals.

That means that flywheel builds some serious speed as you pedal and its this speed that creates the momentum needed to provide a smooth feel.

The M3 also uses a high-end belt drive train too, which doesn’t hurt.

My point is, the M3 is designed to utilize a lightweight flywheel on purpose and users are pretty unanimous in their believes that this cycle offers a very smooth ride.

It’s also capable of providing a serious amount of resistance.

Technically speaking, the M3 comes with an “infinite” amount of resistance levels, which basically means you can make as small an adjustment as you like to the resistance.

But there are also 24 “gears”, which give you an idea as to which level you’re on.

I found this a little confusing, so I reached out to a Keiser rep and he explained to me like this:

The gears give you a ballpark idea as to what level you’re on, but you can still make small adjustments to the resistance between gears.

I hope that makes sense.

Anyway, the resistance is adjusted by a convenient little lever in the front of the bike and your gear level is displayed on the console.

Oh, I almost forgot – you probably noticed that the flywheel is located in the rear of the M3 – well, Keiser was the first brand to do this too.

They decided to put the flywheel in the back to protect it from sweat damage, but I think it looks pretty darn sleek too.

Overall, users are very happy with how smooth the M3 feels to pedal and they also seem to agree that it can provide a boatload of resistance.

It’s also nice that you can make small micro-adjustments to the resistance, but also have the 24 gears to make it easier to replicate workout conditions.

Frame

The M3 comes with a “V” shaped frame and I can assure you that design choice isn’t a coincidence.

Keiser chose this design because it apparently optimizes how many folks of differing heights can comfortably ride this bike.

And according to Keiser, most folks between 4’10” and 7′ should be able to fit on their M3, making this cycle usable for the vast majority of the public.

I always stress the importance of comparing assembled weights too, because this spec gives us a good idea as to how stable or heavy-duty we can expect a bike to feel.

With being heavy a good thing because it’ll make for a more solid base during workouts.

Well, the M3 only comes with an assembled weight of around 87 lb, which is quite light for a bike in this price range.

For the sake of comparison, Sole’s SB900 weighs in at around 160 lb, almost double what the M3 weighs.

But you have to keep in mind the flywheel weight – the M3 doesn’t have a massive flywheel jacking up that total weight.

The aforementioned SB900 has a flywheel that weighs 40 lb more than the M3’s…

And user’s seem to be quite happy with how stable and secure the M3 feels and the fact that it’s lighter makes it easier to move around when necessary.

The M3 comes with a weight limit of 300 lb, which is pretty average for an indoor cycle, but still pretty impressive considering how lightweight this cycle is.

Overall, the M3 scores highly with a lightweight yet sturdy frame that can accommodate folks of pretty much any height.

Warranty

Keiser backs their M3 Indoor Bike with the following residential warranty:

• 10 year frame
• 3 year parts
• 90 day wear items

You know, 10 years on the frame isn’t bad compared to what other top cycling brands are offering, but I’d still like to see a lifetime frame guarantee at this price range.

NordicTrack offers 10 years on their frames and Peloton only offers 5 years, but brands like Sole and Spirit do offer lifetime guarantees.

Three years on the parts is also pretty good compared to the 2-3 years most other brands are offering.

90 days on wear items is a bit short – at this price range, I think 6- 12 months wouldn’t be asking too much.

Overall, the warranty on the M3 is decent, but given the quality and price of this model, I think there’s a little room for improvement.

Features

The Keiser M3 Indoor Bike comes with the following features:

LCD console- the console on the M3 is pretty straightforward, it doesn’t come with any built-in workouts or fans or anything like that. It simply displays all the workout metrics you’d expect from indoor cycle – but it does so very accurately, including the watt output.

Polar H9 chest strap- the console is compatible with Polar heart rate monitors and Keiser even includes an H9 chest strap with purchase.

Fully adjustable seat- you can adjust the height and fore/aft position of the seat, making it easier to find a comfortable riding position.

Height adjustable handlebars- you can’t adjust the fore/aft position of the handlebars, but you can adjust the height position. This is a feature they upgraded on their M3i, as well as the handles themselves – the handles on the M3 are a little dated looking, but they can still get the job done.

Dual-compatible pedals- Keiser takes a lot of pride in the quality of their pedals. These pedals are compatible with sneakers on one side (toe cage) and SPD cleats on the other, giving folks the option to choose how they wanna ride.

Tool kit- there’s some assembly required for the M3, but don’t worry, Keiser includes all the necessary wrenches necessary for the job.

Mat- Keiser also throws in an mat to put under the M3 to help protect your flooring.

Dumbbell holders- there’s also an included set of dumbbells holders, although you’ll have to supply your own dumbbells.

Price

At the time of writing this, the Keiser M3 is going for $1730 directly through Keiser.

I say “at the time of writing this” because this price could change as soon as I publish this article, but the price on this bike has been fairly stable, so I doubt it’ll change too much.

Based on this price, the M3 is certainly an elite home model, but it’s still quite a bit more affordable than other commercial grade bikes like ICG’s cycles, which can easily cost over $3k.

In this price range, NordicTrack’s Commercial S22i and the Peloton Bike are obvious comps, although they couldn’t be more different than the M3.

Both come with large, HD touchscreen consoles, heavy flywheels, and are designed for streaming instructor-led workouts.

So, even though their prices are similar, that’s about where the similarities end.

A better comp though, I think would be ICG’s Ride CX, which also utilizes a fast spinning, light flywheel and costs around $1500 at the time of writing this.

The Ride CX comes with a 1:10 gear ratio, so its flywheel isn’t spinning quite as fast as the M3’s, but it comes with 100 magnetic resistance levels and a 330 lb weight limit.

The M3’s warranty is actually better too: 10 years on the frame vs 5.

Based on these comps, I would say the M3 is priced fairly. I would also argue that it holds its own quite well in terms of performance.

Final Thoughts

Ok, time to wrap things up.

The M3 is a world renowned indoor cycle and it’s easy to see why.

When it comes to performance, it’s one of the most technologically advanced cycles on the market and it definitely has plenty of street-cred for creating a lot of the features we take for granted on cycles these days.

With a fast spinning, lightweight flywheel and a sophisticated magnetic resistance system, it’s capable of offering smooth and challenging workouts for riders of all skill levels.

The biggest downsides I see are that it’s lacking fully adjustable handlebars (a feature that was remedied with the M3i) and that the console doesn’t have some of the techy features folks might be used to.

Like fans, speakers, or built-in workout programs.

But if you don’t care about the console features and are just looking for one of the highest performing cycles around, I think the M3 is certainly a smart investment.