Rowing rigging

Stroke quadrants

Concept: The path taken by the oar from the catch/finish to the axis perpendicular to the longitudinal axis of the boat. A stroke segment consists of two stroke quadrants:
1. catch quadrant: from the catch to perpendicular to the boat and
2. finish quadrant: from perpendicular to the boat to the finish.
Sizes: Measured in degrees. The stroke quadrant differs per rower and is also determined by the chosen span and the length of the inboard handle. It can be used to determine if the strokes of several rowers match in length and quadrants.
   Stroke segment  Catch quadrant Finish quadrant
 Sculling 110° 68°─73°   37°─42°
Sweep rowing 90° 55°─60° 30°─35°
Effect:
+ The larger both stroke quadrants, the longer the draw.
The smaller both stroke quadrants, the shorter the draw.
+ The larger a quadrant, the heavier that portion of the draw.
The smaller a quadrant, the lighter that portion of the draw.
Measure: Using a stroke quadrant meter. This meter is attached to the oarlock and follows the oar or oarlock while rowing. A writing pen attached to the stroke quadrant meter records the quadrants of the rower on an aluminium sheet. A less accurate but less expensive alternative, is to use a marking tape (see figure) on the gunwale and film the rower from a motorboat. The zero point of the tape is at the position where the handle is perpendicular to the boat. The angle is determined by the following formula:
angle (°) = measured distance (cm)/effective inboard handle (cm) * 180/pi
See also: Effective inboard handle (gearing). When filming, make sure that the camera stays perpendicular to the boat.


Stroke length meter and marking tape for measuring the stroke length

Adjust: Can be changed by adjusting the:
1.  foot stretcher: shift between catch and finish quadrant;
2. Rigger position:  shift between catch and finish quadrant;
3. Inboard handle: increasing or decreasing the quadrants.
4. Span: increasing or decreasing the quadrants.

Trim
Freeboard

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