Dreher Elliptical sculls draw on 25+ years of oar design and carbon manufacturing experience to produce exceptional high performance oars. Our Elliptical sculls represent a major departure from previous designs by utilizing an elliptical aerodynamic shaft. This line of Dreher products has an optimized oar shaft and blade shape to increase efficiency both through the air and water.
Dreher’s Elliptical oars have a profile that seamlessly mates an elliptical shaft to a hydrodynamic blade profile in order to minimize both wind resistance on the recovery and drag resistance on the drive. 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.
Elliptical Aerodynamic (EA): This oar design resembles a traditional hatchet shape, but has been modified to optimize aerodynamic advantages. The smooth surface of the blade promotes a clean catch. While our seamless blade-to-shaft transition allows for a cleaner extraction at the release creating less turbulence in the water. If you have used traditional hatchet shaped blades in the past, you will find our Elliptical Aerodynamic sculls maintain a similar feel with the added benefits of reduced drag.
Elliptical Hydrodynamic (EH): The hydrodynamic theory plus prior racing blade performance models inspired the high aspect ratio design of our Elliptical Hydrodynamic sculls. 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, what we believe to be, a cleaner and smoother stroke.
Tool Free Adjustment Option: All of our sculls can be equipped with our Tool Free Adjustable sleeves/collars & handles allowing for inboard and 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
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. The following graph demonstrates the relative drag or the various potential shaft profiles.