Keiser’s M3 Indoor Bike vs The M3i – Everything You Should Know

Keiser has become one of the premiere brands when it comes to indoor cycling and this is mostly due to the success of their highly popular M3i.

And rightfully so – it’s hard to find any user complaints regarding this elite cycle.

But Keiser also offers the original M3, a more affordable option that still has a lot to offer for folks looking to save a few hundred bucks.

What exactly differentiates the M3i from the M3? Is the M3i worth the extra cash or does it make sense to save your money and go with the M3?

Well, these are some of the questions I hope to help you answer with this review.

In this article, I’ll compare these 2 awesome cycles with regards to all their performance specs, features, and price so you can see clearly what differences there are between them.

After reading, you’ll know once and for all which Keiser cycle makes more sense for your home.

Let’s do this.

Keiser M3 Indoor BikeKeiser M3i Indoor Bike
Resistance8 lb flywheel
Micro-adjustable magnetic resistance (24 gears)
8 lb flywheel
Micro-adjustable magnetic resistance (24 gears)
Frame87 lb assembled weight
300 lb weight limit
92 lb assembled weight
350 lb weight limit
Warranty10 year frame
3 year parts
90 day wear items
10 year frame
3 year parts
90 day wear items
FeaturesSimple console
Height adjustable handlebars
Fully adjustable seat
Dual-compatible pedals
Tools included
Console compatible with apps
Fully adjustable handlebars
Fully adjustable seat
Dual-compatible pedals
Heart rate strap included
Dumbbell holders included
Mat included
Tools included

The Keiser M3 Indoor Bike vs The M3i

Even though most of us probably know Keiser as the brand that provides one of the 2 cycles we’re here to discuss right now, they’ve actually made a name for themselves more through the commercial and professional fitness circuit than anything else.

Yup, if you go to any training facility for a professional team in the US, odds are you’ll find at least 1 Keiser machine in there.

Keiser become popular for their patented strength training machines that utilize pneumatic resistance, allowing athletes to train harder while putting less stress on their bodies.

Keiser obviously branched out to the world of indoor cycling too and the rest is history.

It’s funny – Keiser has one of the most popular indoor cycles on the market, yet cycling is just a very small portion of what the company does.

Anyway, at the time of writing this, Keiser only offers 2 cycles to choose from, the M3 and the M3i.

They’ve also got a couple of other home cardio machines to choose from, but it’s their cycles that get the most attention.


One of the hallmarks of the M3 and the M3i is that both cycles utilize lightweight flywheels.

More specifically, we’re talking flywheels that weight in at around 8 lb, which is very light compared to the 40 lb + flywheels found on a lot of cycles these days.

The whole theory that “heavier is better” when it comes to exercise bikes and flywheels is true when talking about bikes designed to benefit from the extra weight.

But Keiser has proven that there are other ways to provide a smooth pedaling motion.

Basically, the M3 and M3i create the momentum necessary to provide a smooth riding experience by getting their lightweight flywheel spinning really fast.

And it’s this flywheel speed that creates the smooth feel users rave about regarding both cycles.

In terms of flywheel weight, there are no differences whatsoever between the M3 and the M3i – both use the same 8 lb flywheel.

There are also no differences between the magnetic resistance systems these cycles use.

The M3 and M3i both come with 24 gears (resistance levels), but you can also make small resistance adjustments between the set gears, so technically these cycles come with micro-adjustable resistance systems with “infinite” levels.

The 24 gear levels just help by giving you some reference for what level you’re on.

Overall, the M3 and the M3i are identical when it comes to their flywheel weights and their resistance systems.


Ok, so when it comes to the performance side of things, these 2 cycles are identical, but what about the bikes’ frames themselves?

Well, both models come with the same 26″ x 51″ footprint, but the M3i is a bit taller when you look at the heights (44″ vs 49″).

This height difference is the result of the tablet holder found on the M3i, but more on that later.

The M3i also weighs a few more pounds than the M3 (92 lb assembled weight vs 87 lb), but realistically, that isn’t enough to make a noticeable difference when riding.

The M3 and M3i are also the same when it comes to their ability to accommodate riders of varying heights.

According to Keiser, both cycles should be able to comfortably fit most folks who are between 4’10” and 7′ tall (which is impressive).

The only real difference I see between the frames of these 2 cycles is that the M3 has a weight capacity of 300 lb, while the M3i has a higher limit of 350 lb.

If you’re well under both limits, this probably won’t make much of a difference to ya, but larger folks should consider this fact when deciding.


The M3 and M3i Indoor Bikes both come with the same residential warranty:

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

Yup, no differences at all between the warranties on these 2 cycles.

I think 10 years on the frame is pretty good, considering a lot of expensive cycles these days are stopping at 5 years (although honestly, I’d still like to see a lifetime frame guarantee).

3 years on parts is also pretty good, considering most in this price range offer somewhere in the 2-3 year range.

90 days on wear items isn’t great or anything, but certainly not a dealbreaker either way.

Overall, I think both cycles come with a solid home warranty.


Ok, time to compare the features these cycles come with. So far, we haven’t seen many differences between these bikes, but there are a few key differences when it comes to this department.

Both bikes come with small, LCD consoles that track your workout metrics and whatnot, but the M3i’s console is also bluetooth compatible with the most fitness apps (the M3’s isn’t compatible).

Another notable difference is found with the handlebars.

The M3 comes with very basic handles that are only height adjustable; the M3i comes with upgraded handles that are more ergonomically correct and fully adjustable (height and fore/aft).

The M3i also comes with an included pair of dumbbells holders, while the M3 does not.

The M3i comes with an included Polar H9 heart rate strap, while the M3 does not.

Otherwise, both cycles come with the same dual-compatible pedals and sophisticated belt drive trains.

Both bikes also come with all the necessary tools required for assembly.

Oh, Keiser also usually throws in a complimentary bike mat with the M3i – they sometimes include this with the M3 too, although at the time of writing this they aren’t.

The M3i also comes with an included tablet holder, something the M3 doesn’t offer.

Overall, when it comes to their features, the biggest difference between these bikes is that the M3i comes with an app compatible console, fully adjustable handlebars, an included heart rate monitor, and dumbbells holders.


At the time of writing this, the M3 and M3i are going for the following prices:

M3: $1,630

M3i: $2,060

These prices may vary a little throughout the year, but generally speaking, there’s usually a $300 – $400 difference between these 2 cycles.

Does the M3i have enough upgrades over the M3 to justify the added cost?

That’s a personal question, but if you ask me, I’d say probably.

The differences between these cycles are pretty subtle when looking at them one at a time, but when you put them all together they’re more substantial.

The upgraded handles are one of the most important differences I see and I can tell ya from experience that having uncomfortable handlebars can be a real bummer when exercising.

The inclusion of an H9 strap is also fairly substantial – if you purchased one separately you’re probably looking at around $60 right there.

There’s also the tablet holder and dumbbell holders – again, not expensive stuff, but every little feature adds up.

Based on the differences between their features, I would say the higher cost of the M3i is fair.

Final Thoughts

But that doesn’t necessarily mean the M3i is the better buy for you.

Recall from the beginning, these 2 cycles are identical when it comes to performance.

The M3 and M3i both come with the same flywheel and the same resistance system and they also both come with the same seat.

And even though the M3i has a higher weight capacity, there really aren’t any differences between their frames either.

No, all of the most notable differences between these cycles are found in the features department.

But if you’re not planning on using fitness apps or watching your tablet during workouts, these upgrades will be of little use to ya.

And when it comes to the fully adjustable handlebars, it’s always nice to have the option to adjust the fore/aft position, but my Peloton doesn’t have fully adjustable handlebars either and I’ve never noticed.

When considering between the M3 and M3i, I think you really have to think about whether or not you like the idea of connecting with fitness apps.

If you plan on using apps, I think the M3i makes more sense; if you don’t care about connecting to apps, the M3 might be the better buy.

Luckily, since both bikes perform the same, there really aren’t any wrong answers here – both cycles are about as elite as they come.

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