Flywheel

By the Watta Team · Updated

Flywheel: The flywheel is the spinning air resistance mechanism inside a Concept2 ergometer that generates resistance during the drive phase of the rowing stroke.

What is Flywheel?

The flywheel is the core resistance mechanism of the Concept2 erg. It is a large fan-shaped wheel enclosed in a housing. During the drive, the chain wraps around the flywheel axle and spins it, generating air resistance. The faster the flywheel spins, the more air resistance it encounters. Between strokes (during the recovery), the flywheel decelerates due to air drag — this deceleration rate is what determines the drag factor. The damper setting controls vents on the flywheel housing: open vents allow more air in, increasing deceleration rate and creating a "heavier" feel. The flywheel provides the smooth, responsive resistance that makes the Concept2 feel natural. It is a passive system — there are no motors or magnets, just air physics.

How Watta Uses Flywheel

The flywheel generates the data that appears on the PM5 monitor — split time, watts, stroke rate, and distance are all calculated from the flywheel's rotation speed and deceleration. Watta captures these metrics from the PM5 display to calculate your Effort Score.

Further Reading

Frequently Asked Questions

How does the Concept2 flywheel work?
When you pull the chain, it spins the flywheel. Air resistance increases with speed. Between strokes, the flywheel slows down. The PM5 calculates your power from the flywheel's acceleration during the drive and its deceleration between strokes.
Do I need to maintain the flywheel?
The flywheel itself requires no maintenance. However, dust can accumulate inside the housing and change the drag factor. Concept2 recommends vacuuming the flywheel housing through the vents every few months to maintain consistent performance.
Is air resistance the same as magnetic resistance?
No. Air resistance is dynamic — it increases naturally with force. Magnetic resistance (used in cheaper rowers) is static and feels artificial. Air resistance more closely simulates the feel of rowing on water and is why the Concept2 is the industry standard.

Related Content

Drag FactorDrag factor is a normalized number on the Concept2 PM5 that measures the actual air resistance the flywheel feels, so you can replicate the same stroke feel on any erg.Damper SettingThe damper setting is the adjustable lever (1-10) on the side of a Concept2 rowing ergometer that controls airflow to the flywheel and affects resistance.Concept2 RowErgThe Concept2 RowErg is the industry-standard air-resistance indoor rowing machine used by Olympic teams, universities, CrossFit boxes, and home gyms worldwide.The DriveThe drive is the power phase of the rowing stroke where the rower pushes with the legs, swings the back, and pulls with the arms to accelerate the flywheel.Ergometer MaintenanceConcept2 ergometer maintenance involves periodic chain oiling, flywheel cleaning, and hardware inspection to ensure consistent performance and longevity.Stroke Power (Peak Watts)Stroke power is the peak or average watts generated during a single rowing stroke, with the PM5 calculating power from the flywheel acceleration during the drive.Split to Watts ConverterDrag Factor CalculatorErg Technique GuideFor Concept2 Users
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