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Competitive comparison – fixed v dynamic rowing machines

...the differences you should be aware of

The ROWPERFECT rowing simulator is the first rowing machine to truly simulate the dynamics of a light racing shell, floating on water. The main frame and seat simulate the boat, and the main bar simulates the water.

 

Simulator or Ergometer – What’s the Difference?

Look at the diagrams above – they clearly show the difference between a fixed rowing machine and a rowing simulator (or rowing boat).

On a fixed ergometer, the rower moves his entire body mass up and down the slide, and must absorb large amounts of momentum at the beginning and end of each stroke, when he stops before the next stroke/recovery. This energy is about 6 times higher with the flywheel fixed compared to floating. The Rowperfect’s floating flywheel dramatically decreases the risk factor for injury to body structures absorbing kinetic energy.

In a racing boat, the rower is attached to only 17 - 23kg, which will move far more than he does every stroke. The rower’s muscles, ligaments and tendons must absorb considerably less energy, and are therefore less likely to be injured. The Indoor Sculler’s moving mass is 17kg and thus the “feel” (scientifically known as Proprioception) is virtually identical between it and a well-rowed racing boat – the rower can train the correct reflexes off the water, so that when he returns to the boat, his Co-ordination Pattern (aka technique) is exactly as it should be.

ROWPERFECT DYNAMICS IN A NUTSHELL

To properly simulate the dynamics of a racing scull, at both turning points (the catch and the finish) the moving mass of the flywheel/stretcher combination must closely match that of a scull (including its blades) is properly train correct coordination and timing. In addition the speed/force relation of the handle during the stroke should also be as identical as possible to that in the boat to produce the "feel" of a true sculling stroke.

A good simulation of the "feel” during the stroke itself can only be obtained when the following condition is met: The kinetic energy of the rotation of the flywheel at the average flywheel speed during a stroke should be equivalent to the kinetic energy of the translation of the boat at the average boat speed during a stroke.

This condition is met by the combination of sprocket size and the moment of inertia of the flywheel of the Indoor Sculler. It then results in the same drive time (same speed of muscle contraction) as in the boat; provided the correct resistance setting is chosen.

So the "feel" of the Indoor sculler is very different to a fixed ergometer - it's almost the diametric opposite in fact - much smoother, and almost identical to the feel of a racing shell. To define "feel" requires a very short explanation of what "feel" really is:

The medical/scientific term for feel is proprioception.  It has two components. The special sense of proprioception is located in your middle ear. It gives us information on acceleration and deceleration, and balance. The general component of proprioception derives from pressure and tension receptors in your joints, muscles and tendons. As you row on the Indoor Sculler, whose dynamics virtually replicate those of a floating boat; your sense of proprioception is receiving almost exactly the same signals as would be the case in a boat without the extraneous information of wind, weather, and waves and so on. This allows you to truly concentrate on producing a perfect rhythm and technique, which is after all the perfect coordination of your muscles by your nerves. Your chances of then maintaining that coordination pattern when you are on the water are best summed up by multiple World Champion Sculler Frans Goebel:

 
“I have never told it before, but for three weeks before the World Championships of 1989 I was unable to row in the boat, and rowed exclusively on the Rowperfect. This gave me an advantage over my competitors; because I was able hone my timing at the catch to perfection, unhindered by wind or waves.” Frans Goebel

Every rowing machine hitherto invented has behaved like a boat which is tied to the wharf. By allowing the resistance mechanism to "float", the Rowperfect allows you to experience the feel of a free-floating boat.

Although the Rowperfect does simulate a racing boat very closely, there are one or two important differences:

  • Because oar handling technique is not required, deterioration of that technique due to fatigue will not serve as an automatic safeguard for the oarsman against over-exertion, as would happen in a boat.
  • Because the oarsman does not have to push the oar away at the beginning of the recovery, but instead is partially pulled back by the elastic shock cord, there is a tendency to row at a slightly higher stroke rate than in the boat.
  • Unlike the water, the main bar is not of infinite length. Therefore, to stabilise the position of the rower within this finite length, there is a slight downward bend in the main bar, with its lowest point at approx. 40 centimeters from the hind leg. In order to influence the dynamics of the system as little as possible, the curvature of this bend is kept at a minimum.

The unit should be levelled in such a way that when rowing, neither of the two support legs is touched by the main frame or the seat. For leveling the unit the front leg is provided with wheels which can be fixed at a variable height in the curved slots in which their axles are located. . When adjusted correctly, the lowest point of the bar will be between 1 and 1.5cm below the highest (front) point.

Comparison of fixed and dynamic Rowing Machines

On analysis, the two most critical points in the rowing stroke where technique can make a difference to raw power are:

(1) How the coordination of the catch is carried out, and

(2) Same for the finish.

1. This should be done so as to place no backward pressure onto the stretcher that is not transferred via the blade in the water and then levered forward against the oarlock which in turn moves the boat. Any Backward pressure without the counter balance of force in the opposite direction against the oarlock results in the boat being driven backwards. Put simply this would mean the rower has crashed their body into the front stops and stretcher before taking the stroke or has started the stroke (leg drive) without connecting with the water. Try doing this on the Indoor Sculler and see how the machine responds. It will fairly quickly force you to concentrate on a coordinated approach with timed power application at the catch. Initially this will be a challenge and require significant concentration in order to maintain the carriage and seat working in a stable central position. When you have it right the forces are in equilibrium and the seat stays more-or-less stable (actually the seat moves about as much as your pelvis tilts each stroke - don't sweat the seat staying too still)

 2. The same logic applies at the finish of the stroke., as perfectly summarised by Jim Battersby: On the fixed platform machine you can bash into the front as much as you like or for as long as your back and body can take it. I'd suggest that for those who haven't tried: Learn how to get it right on the Rowperfect then get off and onto the Concepts. If you are not left with the immediate impression that one of them was like rowing and the other something quite different I'd be very surprised.

Jim Battersby
Australian Champion Sculler, Olympic and World Medallist rower

 

Comparison of Rowperfect (dynamic) & fixed rowing machines 

Feature 

Benefit  

Rowperfect  

All other rowing machines available today 

Double action - creates accurate reproduction of the physics of rowing a floating boat

The closer your off-water training simulates a real boat—the more effective the training.

Allows more rapid acquisition and honing of co-ordination.

Reduces the forces acting on knees and lower back

Yes

No

Mass balanced - 17.5kg

Moving flywheel mechanism

Allows you to learn and practice good technique.

It is very sensitive to proper co-ordination of movements.

Yes

No

Seat requires balance

Forces you to sit and pull symmetrically (so you avoid developing incorrect body alignment while training off-water).

Yes

No

Handle force equivalent to boat

Allows you to train specifically for rowing.

Yes

No

Body mass corrected readout *

Rowperfect presents the fairest comparison of performances of oarsmen of different weight. A world’s first!

Yes

No

Boat class variable *

Train specifically for various events

Yes

No

Power-per-pulse available *

Revolutionary training tool - monitor cardiac output as never before

Yes

No

Full steel construction - no easily breakable plastic extrusion parts

Designed to last thousands of hours, with regular maintenance

Yes

No

Inherent flexibility equivalent to rigger + shoulder + footstretcher in a boat.

  • Flexibility = Strength
  • Stresses are minimised on both machine and rower!
  • Reduces damage to machine and injury to rower.

Yes

No

 

 NEXT > The physics behind the Rowperfect advantage

 

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