The M Connect Display broadcasts over Bluetooth 4.0 on four profiles: CSCS, FTMS, CPS and Keiser Proprietary. Those are the profiles third-party cycling and fitness apps read for cadence, speed and power, so an app that speaks any of them will see an M3i. The same radio reaches heart rate monitors and the major group cycling projection systems, and the Keiser M Series App and M Series Group App run on it too. Nothing sits between the bike and the app: no converter box, no external dongle and no separate sensor clamped to the crank.

Nothing below the handlebar. The frame, the 92 lb, the four-way Studio Curve bar, the four-way seat, the Poly-V belt and the 4 ft 10 in. to 7 ft fit are shared item for item, so the question is only which screen you want above them. An M3i gives you 24 gears on a black-and-white numeric M Connect Display running from two AA cells, which is everything a rider working from watts and cadence needs. The M3i Studio Plus gives you 72 gears in colour, a profile the screen remembers and a generator in place of the batteries. Its screen carries 86 percent more area than the M Connect, it adds ANT+ beside Bluetooth so an older chest strap pairs without an adapter, and it runs four training modes off that stored profile: % of FTP, % of HRmax, METs and Speed. Neither screen touches the magnetic brake underneath, so both bikes ride the same and the readout is the only choice to make.

Two things move in opposite directions, so read both before deciding. The M3i Studio carries the Studio Display with 72 gears where the M3i carries the M Connect with 24. The Studio's handlebar is the two-way Studio Align, which moves up and down only, and its rider fit is 5 ft to 6 ft 2 in. against the M3i's 4 ft 10 in. to 7 ft. The Studio is also a smaller machine at 44 in. and 87 lb. A rider taller than 6 ft 2 in. is outside the Studio's range and inside the M3i's.

Both, and the second explains the first. The magnetic brake moves in infinite incremental changes with no detents in it, and the M Connect Display lays 24 numbered gears over that continuous range so a setting can be called out loud, written into a session plan and found again next week. The Studio Display on the M3i Studio Plus maps the same brake onto 72 gears, which gives finer steps between one setting and the next.

Yes, right to the top of it. Rider fit on the M3i runs 4 ft 10 in. to 7 ft, the widest band across the M Series bikes, and it comes from the four-way Studio Curve handlebar working with the four-way seat. A rider over 6 ft 2 in. should note that the M3i and the M3i Studio Plus are the two bikes in the family that reach them.

350 lb, and Keiser classifies the frame under EN957-10 at that rating. It holds for a rider in the saddle, out of the saddle and in the moment of getting on. The 92 lb the M3i weighs itself answers a different question, which is how many people it takes to put the bike where it is going.

About 45 minutes. The M3i arrives partially assembled and the remaining work is bolting the frame together and fitting the contact points. A torque wrench and crowfoot wrenches are what the job wants, and the Keiser M Series Assembly and Maintenance Kit is sold separately for exactly that.

Cadence in RPM, power in watts, kilocalories, elapsed time, distance, heart rate and the gear you are in, all on one screen. Behind the live numbers it keeps running averages for cadence, power and heart rate, a trip distance and an odometer. Power is the figure worth training against, because it is the only one that stays comparable when cadence and gear both move.

The M3i measures 49 in. / 1245 mm tall, 26 in. / 661 mm wide and 51 in. / 1296 mm deep and weighs 92 lb. Measure the route before the room: 26 in. across the bar has to pass the front door, the hallway, the stair turn and the doorway at the end of it, and at 49 in. the M3i is the taller of the two frames Keiser builds in this family. Once it is standing, leave clear floor behind the saddle for mounting and clear air above the bar for a rider riding out of the saddle.

Keiser builds the M3i in the United States from domestic and globally sourced material, and classifies the bike under EN957-10. Warranty on M Series Cardio runs three years all inclusive, excluding labor and wearable parts, with ninety days on the wearable parts: handles, pedal cage, straps and saddle.

The M3i falls inside every accessory scope in the range. The Keiser Bike Dumbbell Holder is the M3 and M3i fitting by its own product name, though a frame built before May 2016 has no tapped hole for it and wants a retrofit first. The M Series Assembly and Maintenance Kit is scoped to all M Series Indoor Bikes, the Keiser Floor Mat to the wider set of M Series Cardio machines, and the Keiser Gel Seat Cover to the Keiser saddle or any other "narrow" saddle. Four products, four separate orders.

Saddle height first, with the rider sitting on the bike and their feet on the pedals, because every other measurement is taken from where the saddle ends up. Saddle setback second, since sliding the seat fore or aft moves the rider closer to or further from the grips and changes the reach you are about to set. The handlebar last: raise or lower it for the back the rider wants to hold, then use the fore and aft travel to bring the grips to the rider. Working the other way round, with the bar bolted where it arrived, leaves a rider stretching for it for the whole session. Both posts carry numbers, so the four settings are worth writing down once a rider is happy.

Yes, and the four-way seat and four-way handlebar are what make the handover quick. Note the numbers on the seat post and the handlebar post once each rider has a position they like, and the swap afterwards takes under a minute. The M Connect Display holds no stored rider profile, so figures on the screen belong to whoever is riding at that moment.