Drag Factor Calculator
Two ergs set to the same damper number rarely produce the same drag, which is why the lever is a poor guide. Tell this calculator your weight, experience and target and it will point you at a drag factor worth testing at, confirmed properly through the PM5.
What drag factor should I use on a Concept2 erg?
In Irish clubs most openweight adults test 2k at drag 130-140, the band that best imitates a heavyweight boat. Women and lightweights usually suit 110-120, while juniors and novices learn fastest at 100-115. Setting drag 200 does not make the session harder in any useful sense; it simply shifts load onto different muscles and invites injury. Ignore the damper lever and confirm the real number in the PM5 menu first.
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Recommended drag factor
Why this number
Drag factor primer
| Profile | Drag range | When to use |
|---|---|---|
| Lightweight / women openweight | 110-120 | Reflects the lighter boat. Irish lightweight 2k testing at national level runs at 110-120. |
| Heavyweight openweight | 130-140 | Heavyweight boat load. Senior Irish men generally test 2k in the 130-140 window. |
| Distance / endurance | 110-130 | Steady mileage: 5k, 6k, 10k and beyond. Lower drag looks after the rating and the lower back. |
| Sprint / max power | 130-140 | Short maximal work - 500m, 10 strokes, one minute. Nudge the drag up slightly for peak watts. |
| Juniors / beginners | 100-115 | Groove rhythm, posture and connection before any thought of extra resistance. |
Drag factor myths
Myth: Higher drag = harder training = better results
It is not. What higher drag really does is trade rating for force per stroke - a different recruitment pattern, not extra fitness. Squads at clubs on the Lee, the Liffey and the Shannon train at 130-140 because that is boat feel. Sitting at drag 200 grinds out fewer strokes per minute and courts a lower-back problem for no aerobic return.
Myth: Damper level 10 = drag 200
It is not that simple. The lever only sets the vent opening on the flywheel; the resulting drag depends just as much on dust, altitude and humidity. On one erg damper 10 gives 175, on the next 220. The PM5's Display Drag Factor screen shows the true value - set the lever by that reading, not by the printed numbers.
Myth: Drag factor changes your watts at a given split
It cannot. The Concept2 power formula, watts = 2.80 / (split/500)^3, fixes watts to the split whatever the drag: a 1:50 split is about 263 watts whether the drag reads 110 or 140. Drag decides how the work feels, where the rating settles and which muscles empty first.
Myth: Boat-class drag factor matches the boat feel exactly
Roughly, no more. The published boat-class figures (single 1x around drag 100-110, eight 8+ around 130-140) are honest approximations, but an erg fan can never copy water. Begin from the boat-class number and adjust from experience rather than treating it as fixed.
How drag factor works
What drag factor measures
After every drive the flywheel slows, and drag factor is the measured rate of that slowing. The PM5 recalculates it each stroke and holds the average in its menu. Heavier drag means the wheel loses speed quickly, so the next catch must supply more force to recover it. The Concept2 ergometer reports the value regardless of where the lever sits.
How to set drag factor
Open Menu on the PM5, then More Options, then Display Drag Factor, and row a few strokes to give it data. Shift the damper lever until the reading matches your target, then look again once you are warm. A clean flywheel and a dusty one behave differently at the same lever, so verify ahead of each test.
Boat-class equivalents
Concept2's guide numbers put singles and lightweight boats near drag 100-110, pairs and fours around 115-125, and the eight at 130-140 - reasonable openers, nothing more. When the drag is settled, run your goal pace through the training pace calculator for zone-by-zone targets, and the erg pace calculator will convert any split into watts and a 2k projection.
Settle drag and stroke rate together rather than in isolation. Cross-check output with the watts to split converter once the number is set, then give the setting a fair trial on a couple of sessions from the erg workout library.
Frequently asked questions
Is drag factor 130 the same on every Concept2 erg?
It is. Because drag factor is an absolute reading of flywheel deceleration, every Concept2 reports it on the same scale. Drag 130 on a new Model E at the National Rowing Centre in Inniscarra is the identical load to drag 130 on an ageing Model D in a Dublin gym; only the lever position needed to produce it varies, since older flywheels usually demand a higher damper setting.
Should beginners train at drag 200?
No, and coaches should stop them. Until the catch and posture are reliable, drag 100-115 is the place to be. Heavy drag on a raw stroke is the quickest way to hurt a beginner's back, and it embeds a handle-snatching habit that lingers for years. Add drag only after the movement is consistent.
What drag factor do elite Irish and Olympic athletes use?
Senior Irish men typically sit at drag 130-140 for 2k testing, with women and lightweights at 110-120, in line with international practice. The O'Donovan brothers and Fintan McCarthy test within these bands - the drag matches the boat they race, not a number chosen to look tough.
Does drag factor affect calorie burn?
Not directly. The PM5 derives calories from watts through kcal/hr = (watts * 4) + 300, and the split-to-watts relationship is fixed by formula, so the same split shows the same calories at any drag. What shifts is behaviour: different drag nudges your rating and stroke length, moving average watts and, with them, the session's calorie total.
How often should I check drag factor?
Ahead of every test, always. As dust gathers in the flywheel the lever-to-drag relationship drifts week on week, and vacuuming the cage every couple of months slows that down. For everyday steady state one check at the start of the session will do; for a 2k or benchmark piece, confirm the number again in the warm-up.
What is the difference between damper lever and drag factor?
One is a control, the other a measurement. The lever (1-10) varies the airflow into the cage; drag factor records how fast the wheel actually decelerates, which also reflects dust, altitude and humidity. Base every prescribed load on drag factor - the lever is only the means of reaching it.
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Convert split to watts, calories and predicted 2k, 5k, 6k, 10k times.
Stroke Rate Calculator
Distance per stroke from rate and split, or vice versa.
Training Pace Calculator
UT2/UT1/AT/TR/AN paces, stroke rates and coach-ready intervals.
Right drag, honest numbers, better coaching.
Every erg piece a member logs in Row HQ carries its drag factor, split, rating and watts, so a coach can tell at a glance whether the squad trains where the plan says.