Rigging Dreher Carbon Riggers:
“Rigging”: is the term used to describe the determination and subsequent adjustment of the outrigger height, pitch (oar lock face inclination from the vertical), spread or span (distance between the pins in sculling or centerline of the boat to centerline of the pin in sweep rowing), shoe location (horizontal, vertical and angle), oar length and collar location as well as other adjustments such as boat trim and blade angle at the catch and finish position. The rigging objective being to adjust the boat to comfortably fit the rower whole maintaining maximum efficiency of the rowing stroke.
Pitch: Pitch is the measurement in degrees that the face of the oarlock is inclined from the vertical. Pitch compensates for the flexibility of the oar/rigger system and the imbalance of forces resulting in the blade attempting to dive. The result is that an oar with too little pitch will go deep and be difficult to extract at the end of the stroke. Because the pitch required is dependent on how stiff the system is you must estimate how stiff your equipment is as a starting point. Many years ago when all boats and oars were made of wood we used about 7 – 8 degrees of pitch with some in the oar and some in the lock. In some countries like Germany that is still the case. Today with the stiffer composite boats, carbon oars and riggers, the pitch of 4 degrees is molded into the face of the oarlock and the pin that the lock swivels about is set at zero degrees in all directions. If the oar, scull or rigger is constructed correctly all the extra pitch bushings except for the 4-degree pair that come with modern oarlocks are seldom used. Most oars and sculls are manufactured well within ½ degree of 0 degree pitch, except those built for the German market which uses 3 degrees. Carbon tubular riggers have pins set at 0 degrees with pitch inserts used to decrease the molded in 4 degrees to 2 or 3 degrees. This is because the system is very stiff. On the other hand a recreational or club single with a wing rigger may use pitch inserts to increase the pitch to 5 or 6 degrees. To determine if you need to correct pitch you must row the boat and observe how the oar tracks through the water. Assuming that you row correctly and have the oar seated against the lock face the oar blade should be buried completely and stay at a constant depth and come out cleanly at the finish. If the result of a test row indicates a pitch adjustment then try different degrees of pitch inserts in pairs and repeat the test to see if it makes a difference.
Rigger Spread or Span: Spread is the distance between the centerlines of the lock pins of sculling boats. Span is the distance between the centerline of the boat and the centerline of the pin and sweep boats. For sculling boats the spread ranges between 156 and 163cm with most common being 160cm. Sweep boats will range between 81 to 86cm. To assure equal leverage a measurement from the port side track to the starboard lock and vise-versa is made. The actual measurement number is not noted, but must be identical at all positions, both port and starboard so that the boat will pull straight.