How do magnetic rowing machines work?

The basic parts inside a magnetic rower

Lift the plastic cover off most magnetic rowers and you find the same handful of parts. A strap or chain runs from the handle to a pulley and one-way clutch. The clutch turns a flywheel during the drive and lets it freewheel on the recovery. Close to the flywheel rim sits a curved bracket holding several permanent magnets. A cable or small motor moves that bracket nearer to the rim or further away.

The flywheel itself is usually steel with an aluminium or copper-coloured ring, or a solid conductive disc. What matters is that the rim is made of a metal that conducts electricity well. The magnets never touch it. There is always a small air gap, which is why magnetic rowers have no brake pads to wear out and make very little noise.

• Handle and strap: transfers your pull to the mechanism.
• One-way clutch: drives the flywheel on the pull, freewheels on the return.
• Flywheel with conductive rim: stores momentum and carries the eddy currents.
• Magnet bracket: sets the gap between magnets and rim.
• Adjuster: a knob, lever, handle buttons or an app, depending on the model.

Eddy currents: where the resistance comes from

When a conductive metal moves through a magnetic field, small loops of electric current form inside the metal. These are called eddy currents. Each loop creates its own magnetic field, and that field opposes the movement that created it. The result is a drag force on the flywheel, even though nothing is touching it. The energy you put in turns into a little heat in the rim.

The same principle is used in some train brakes and in many indoor bike trainers. It is smooth because there is no friction surface, and it is consistent because the magnets do not wear. On a rower, it means each stroke meets a steady, even pull rather than the grabby feel some older friction brakes had.

Eddy current drag does rise with flywheel speed, so pulling harder still feels harder. However, the change is gentler than on an air rower, where drag rises sharply as the fan spins faster. That is one reason magnetic rowers rely on a level setting to change the feel, rather than on how hard you pull alone.

Why moving the magnets closer adds resistance

Magnetic field strength drops quickly with distance. With the magnets far from the rim, only a weak field reaches the metal, so the eddy currents are small and the drag is light. Turn the knob up and the bracket swings closer. More of the field passes through the rim, the eddy currents get stronger and the flywheel resists more.

On a manual rower, a numbered knob or lever pulls a cable that moves the bracket in small steps. Eight, ten or sixteen levels are common. The numbers are not a standard unit, so level 8 on one brand will not match level 8 on another. Some makers quote a peak resistance in kilograms, such as 40 kg on the MERACH R15, but that figure is a maker's measure and not directly comparable between brands either.

How electromagnetic rowers set levels automatically

Electromagnetic rowers replace the moving bracket of permanent magnets, or add to it, with coils of wire. When current flows through a coil it becomes a magnet. The console controls that current, so it can change the strength of the field instantly without any moving parts. Turning the level up simply means sending more current to the coils.

Because the level is set electronically, it can be changed from buttons on the handle, from the console or from an app over Bluetooth. Models such as the MERACH Q1S electric and the MERACH R15 electric work this way. An app can then raise or lower the level during a programmed session, which is what makers mean by automatic or app-controlled resistance.

The trade-off is that electromagnetic rowers need mains power to set resistance. A manual magnetic rower usually runs its small console on batteries, or on a generator in the flywheel on some models.

Note:Electromagnetic rowers plug into the mains. Keep the lead clear of the rail and seat, do not run it under a rug, and switch off at the wall before removing any cover. If the unit trips a fuse or smells hot, stop using it and contact the maker's support or a qualified technician.

What this means for how a magnetic rower feels

Because the level, not your pulling speed, does most of the work, a magnetic rower tends to feel even and predictable. Each stroke at a given level feels much like the last. That suits people who want a quiet machine and a simple dial to turn. It feels less like a boat on water than a water rower, and it lacks the rush of an air rower when you sprint.

The flywheel size also matters. A heavier flywheel keeps spinning between strokes, so the recovery feels smoother. Lighter flywheels on compact models can feel a little jerky at the catch. For a fuller comparison of types, see our guide to water or magnetic rowing machines and the explainer on whether magnetic rowers are any good.

If you are ready to compare models, our best magnetic rowing machine guide sets out folding, levels and app support side by side.

Compare magnetic rowers →

Frequently asked questions

Do magnetic rowing machines need maintenance? Very little. Because the magnets never touch the flywheel there is nothing to wear on the brake itself. Keep the rail clean, check the strap and bolts now and then, and follow the maker's manual for any lubrication of the seat rollers.

Are magnetic rowers quieter than air rowers? Yes, in general. There is no fan moving air, so the main sounds are the seat rolling and the strap winding. Some listings quote figures below 30 dB, but those are the maker's own figures and room conditions vary.

What is the difference between magnetic and electromagnetic? A standard magnetic rower uses permanent magnets moved by a knob or lever. An electromagnetic rower uses electric coils controlled by the console, so levels can change from buttons or an app without moving parts, but it needs mains power.

Is level 16 on one rower the same as level 16 on another? No. Levels are set by each maker and are not a shared unit. Compare levels only within the same machine, and use watts or /500 m split from the console if you want numbers that make more sense across sessions.