Concept2 Drag Factor Explained (and the Setting to Use)

The damper lever on the side of your Concept2's flywheel is the most misunderstood setting in indoor rowing - and drag factor is the number that actually tells you what it's doing. If you've ever wondered why "damper 5" feels different on two machines, or what setting you should use, this is the number to learn.

What drag factor actually is

Drag factor is a measure of how quickly the flywheel slows down between strokes - in other words, the true resistance the machine is giving you. The PM5 calculates it every stroke from the flywheel's deceleration, so unlike the painted damper numbers (1–10), it's a precise, repeatable figure.^[1] Crucially, it accounts for things the damper number can't: air density, altitude, and how clean your flywheel is. A dusty flywheel in a garage gives less drag at "damper 5" than a clean one - the damper number lies, the drag factor doesn't.

How to check drag factor on a PM5

It's tucked in the menu, not on the main screen. From the PM5 main menu: More Options → Display Drag Factor, then take a few strokes - the number settles after a stroke or two. Check it at the start of a session and adjust the damper lever up or down until you hit your target.

What drag factor should you use?

There's no single "correct" number, but most rowers train in a sensible band. Set the damper to land in the range that fits you:

A good default is a damper of 3–5, which puts most people around a drag factor of 115–130 and mimics the feel of an on-water shell.^[1] Higher isn't "harder" in a useful way - it just changes the feel and can load your lower back. Your pace comes from how hard you pull, not the lever.

Drag factor vs. the damper number

Think of the damper as a coarse airflow control and drag factor as the precise readout of the result. Two reasons to use drag factor over the damper number: it makes your settings comparable from machine to machine (essential if you train across different ergs or compare scores), and it stays honest as your flywheel collects dust. For the deeper conceptual explanation of why a higher damper isn't a harder workout, see our guide to damper setting vs. resistance.

Keep it consistent

If your drag factor drifts down over weeks at the same damper setting, your flywheel housing needs a dust-out - part of normal Concept2 maintenance. Set your drag factor at the start of each session and your data stays comparable week to week, which is the whole point of training on the world's standard monitor. New to the numbers? Start with how to read your monitor and split times.