More than 20 years ago, Keiser set out to create a bike that would exceed the demands of indoor group cycling.
- A bike that fits riders of all body shapes and sizes
- A bike that achieves a quiet — but true — road bike experience inside your gym or home
- The ONLY bike built in the United States to ensure the tightest quality control
...and we accomplished it all with
THE SIMPLEST OF
Thanks to the lessons learned from our past generations of bikes and our constant innovations, the Keiser M3i isn’t just any indoor group cycling bike.
It’s the industry’s only indoor group cycling bike built around YOU. That’s...
YOU the rider
YOU the gym owner
YOU the service technician
HERE’S HOW WE DID IT.
OF ALL SIZES
Many indoor group cycling bike manufacturers talk about providing a road-bike experience, but they failed to recognize what’s important about road bikes:
FRAMES VARY TO ACCOMMODATE RIDERS OF DIFFERENT SIZES.
Our solution was to engineer the industry’s FIRST V-shape frame for an indoor bike
Our V-shape frame design allows the M3i to mimic different road-bike frames by allowing the seat and handlebars to be simply raised in conjunction with one another to adjust for longer legs, torsos and arms.
FIRST TO ENGINEER A V-SHAPE FRAME
Other indoor group cycling bikes mistakenly place the rider’s sweat zone directly over the flywheel and other vulnerable mechanisms — an obvious engineering flaw that leads to corrosion, excessive cleaning and a shorter bike life.
Keiser was the FIRST to put the flywheel at the rear of a bike, allowing the M3i to be more reliable, easier to clean and better protected from sweat and corrosion.
Further protection of drive-train
The angled channel on the bike frame flows excess fluid away from the drive-train.
Less maintenance, longer bike life
With superior sweat protection, gym owners can save money through lower maintenance costs and a longer bike life.
FIRST TO ENGINEER A REAR-WHEEL DESIGN
It’s easy to “claim” accuracy, but we guarantee it. As the FIRST company to use magnetic resistance, Keiser revolutionized indoor cycling by delivering a quiet, reliable ride with immediate accurate data for EVERY M3i bike.
And unlike most competitors’ bikes, the M3i has been certified for accuracy
The nerve center of the M3i
The simple, elegant axle assembly is the core piece responsible for predicting and delivering accurate ride data, EVERY TIME — and EVERY COMPONENT is inspected to meet precise tolerances.
TRUE POWER READINGS
The M3i is the FIRST indoor bike to receive the globally recognized EN957-10 certification for accuracy and safety.
IMMEDIATE RIDE DATA
The FIRST indoor bike designed to predict the power generated at any speed in any gear — ensuring that both instructors and riders are provided with accurate ride data immediately.
Our relentless Quality Control procedures ensure that every M3i delivers the same immediate accurate ride data, bike after bike after bike. And every day an M3i production bike is randomly dyno-tested to ensure quality and accuracy
FIRST TO USE MAGNETIC RESISTANCE
The competition endorsed Keiser’s engineering by following our lead on using magnetic resistance — but they should have also copied our drive-train design.
Our simple drive-train, with just a single Poly-V belt, produces the higher speeds necessary for a lighter-weight aluminum flywheel to provide the kinetic energy and magnetic resistance to simulate a good road-bike experience. Using an outdated drive-train, designed for heavier flywheels, our competitors must use a perimeter-weighted flywheel to accomplish the same thing.
They even brag about their perimeter-weighted flywheel, cog-belt drives or crank-arm-to-flywheel ratios. But what they’re really telling you is...
THEIR BIKE WRONG.
QUIET, SMOOTH AND
To design their indoor bikes right, our competitors will have to copy Keiser’s single Poly-V belt drive-train, because it’s the perfect balance between SIMPLICITY and PERFORMANCE
The Poly-V belt is the key to our drive-train design because it transmits very high loads over very small pulleys, achieving a good road-bike experience:
- Without a perimeter-weighted flywheel
- Without a more complicated drive-train
- Without the unnecessary noise and vibration of a cog belt
No required maintenance, zero adjustments
The belt’s pre-tension design also requires zero adjustments, and the M3i drive-train requires no maintenance other than routine inspection.
The Poly-V belt is THE choice of automotive manufacturers
The Poly-V belt is the preferred choice to run the accessories on the front of car engines, because it’s so quiet, durable and reliable.
FIRST DRIVE-TRAIN TO USE A POLY-V BELT FOR MAGNETIC RESISTANCE
Many indoor group cycling bike manufacturers talk about the distance between their bike’s two pedals, and boast about their narrow Q Factor. But their bikes were built around the narrow shoes and pelvises of elite cyclists, even though footwear of any width and people of all body shapes can be found in group cycling classes.
WHY WOULDN’T YOU DESIGN A BIKE TO FIT
CURVED CRANK ARMS
TO FIT WIDER HIPS AND BULKY SHOES?
Instead of using straight crank arms to achieve a narrow Q Factor, Keiser recognized the need for versatility. We added curvature to the M3i crank arms to maintain the proper distance for wider hips and any type of rider footwear, from narrow bike shoes to the bulkier gym shoes most commonly worn in group classes.
KEISER M SERIES PEDAL
Keiser also set a new industry standard with our SPDcompatible M Series indoor group cycling bike pedal. Engineered beyond consumer standards for group classes, it’s more than a pedal — it’s a game changer, providing superior comfort, safety and durability.