When I learned to row, we had only wooden handles on fixed-length oars. Depending on the manufacturer, the handles were different in size or diameter. While we beginners were obviously not allowed to practice any woodcarving, we became quite experienced in this craft later in our careers when we knew more about the sport. We convinced our coach that it was advantageous to shave off a few millimeters of handles that were too thick. Some rowers became quite adept with a file and carved indentations in the handles to suit their hands. Some went so far that a handle would sometimes break under the strain of a hard stroke.

 Fixed-length oars with wooden handles are becoming extinct, but it’s still possible to order them. With modern oars, you choose your handle size, and while the dimensions can no longer be altered with a file, you can always switch to a different one. Which size is best? And how do you decide? Read on.

The most important consideration, of course, is you, the rower who must transfer power efficiently to the oar without injuring yourself while repeating hard and light strokes many times under varying conditions. To get an idea of what’s involved in determining the correct size, imagine hanging by your hands from a bar with your feet off the ground. To hold on to the bar, the middle phalanges of your fingers must be able to pass the bar’s apex. To get them there, you have to angle your wrist, which requires a lot of strength. Moreover, your hands, lacking sufficient grip, will slip off easily. All this extra effort will fatigue your hands and lower arm muscles, which can lead to such symptoms as tendinitis. While holding on to a thin bar is easier, it will soon hurt because the contact area between your hand and the bar is small and will exert  unsustainable pressure on your fingers. 

You also must be able to feather and square the blade, which requires applying torque—easier when your handle is larger. The larger the radius, the larger the leverage. As oars have become lighter over the years, the diameter of the shafts has become smaller, reducing friction between the sleeves and oarlocks. At the same time, because blades are wider, rowers need a firmer grip to direct the oars securely and precisely.

Another consideration for choosing handle size is the stiffness and stability of the inboard portion of the oar. As experience from the old days teaches us, handles can break when too thin.  You want to have a stiff inboard oar so that force is transferred without loss and your feel for the blade is not inhibited. A handle that’s too thin will bend too much and soften the overall oar, especially in sweep rowing, That’s why the handle is larger for the inside hand in sweep.

Many years of experience have led oar manufacturers to set handle sizes for sculling and  the outside hand in sweep between 32 and 40 millimeters and the inside hand in sweep from 42 to 46 millimeters. These numbers are universally accepted, and all manufacturers offer a variety of choices. 

Nowadays, handles are interchangeable, so you can try different sizes and find what’s most comfortable easily. Because the range of choices is limited, handle size has no appreciable effect on performance, so personal preference and comfort should be the deciding factors. When you find the handle size that works best for you, you’ll likely stick with it for a long time. Soon you’ll get so used to it that it will be embedded in muscle memory and seem like an extension of your arm.