Dreher Aerodynamic oars draw on 25+ years of oar design and carbon manufacturing experience to produce exceptional high performance oars. Our Aerodynamic oars represent a major departure from previous designs by utilizing an elliptical aerodynamic shaft and hydrodynamic blade. This line of Dreher products has an optimized oar shaft and blade shape to increase efficiency both through the air and water.
Dreher’s Aerodynamic oars have a profile that seamlessly mates an aerodynamic elliptical shaft to a hydrodynamic blade profile in order to minimize both wind resistance on the recovery and drag resistance on the drive. In this way the wind resistance is minimized on the recovery when the sum of the the boat velocity and angular oar velocity is at it’s fastest. Less wind resistance on the recovery and improved stability equates to the potential for greater speed for the same effort. The more efficient the sculler and the faster the boat class, the greater the potential for speed improvement.
Aero EH and EHX: This design aerodynamic, but with a conventional roll wrapped shaft. The shaft has an elliptical profile of a helicopter rotor blade. It is manufactured at essentially the same cost as our standard racing sculls.
The hydrodynamic theory plus prior racing blade performance models inspired the high aspect ratio design of our Aero EH and Aero EHX. The blade shape is narrowest by the blade/shaft interface and then increases in surface area and width towards the tip of the blade. By optimizing the aspect ratio of the blade design we have been able to create a blade that takes into account the various forces on the blade during the drive phase allowing for a cleaner smoother stroke.
Aero EA and EAX: This oar design resembles a traditional hatched shape, but has been modified to optimize aerodynamic advantages. The blade is quiet with little back splash at the catch. The blade maintains the same smooth blade-to-shaft transition allowing for a cleaner extraction at the release. These blades will perform best with a shorter overall length and inboard setting which will help optimize the angle of attack. These two two newest aerodynamic sculls are the EH and EA. These both have the smaller profile on the feather with narrowest part of the oar close in the bottom third of the shaft. We also offer these two oars in EHX and EAX in high modulus/twill carbon as well.
Tool Free Adjustment Update: Either price point oar or style of blade can be equipped with the Tool Free Adjustable (TFA) sleeves/collars to each adjust inboard / outboard adjustment in under 10 seconds. For every 90 degree rotation of nut on the segmented carbon screw, the sleeve / collar assembly will move 0.25 cm either in or out. So a full turn of the adjustment nut will move the sleeve /collar and 1 cm. The Patent on this assembly was approved in February of 2017: Patent No. US9573668
The new TFA has a new nut locker which is integral to the assembly, which is no longer a separate part that can get lost or easily broken. This new robust, lightweight clip will lock every 90 degrees of rotation and you will hear it click when it passes each .25 cm of adjustment. In addition, the latest design has a new the “onboard adjustment wrench” as well.
When customers opts for the TFA feature they will get the newest design. In addition, we will offer a free upgrade of the nut locker replacement after May 1, 2017.
Our aerodynamic shafts have an elliptical profile in region of the shaft that goes the fastest. The relative drag associated with our elliptical design, is a fraction of that associated with what our competitors circular design. The effect is especially noticeable into a headwind, where the sculler can feel the oars slicing through the headwind. See the graph showing the relative drag or the various potential shaft profiles.