Rigging, Leverage Formula and The “M”

Reader Mike writes:

Hi Mike – love your site and your book – one question I can’t seem to find the answer to… What is the “M” value of CII Fat Smoothie sweep oars? Look forward to the answer…

Mike is talking about the leverage formula that I use to keep track of the load of a specific rig. I discuss it in detail in several places, but basically here is the formula:

[(L-I)-B/M]/S

In the equation L= oar length, I= inboard, B= blade length, M is a variable, S is the spread, and B/M togther represent where the center of pressure is on the blade.

Two things of importance here:

1. Measurements are metric
2. Do not use this formula to compare between different blade shapes, just between oars with the same blade shape.

The M that reader Mike refers to helps find the approximate center of the oar. The number that I use is, for rectangle shaped oars (or close to it)  2 (for 1/2 the length of the blade), and 3 (for 1/3 for the length of the blade) for macons. I am not sure what I would use for something like a delta, I would have to measure it first, or talk to the maker.

In this case,  a for CII Fat Smoothie that is 52 centimeters long, the M would be 2.

There is debate as to whether this number, and in fact the formula, have value. I’ve found it to be helpful for me in keep track of things, although I strongly caution again anyone to use it to compare different blade shapes.

What do you use to keep track of your leverage/load?

16 Ways to Get Better at the Physics of Rowing

(This is scary stuff. Buckle your seat belt.)

Physics: the science of matter and motion.

(Told you it was going to be scary.)

If you were pressed hard you could divide rowing into two distinct spheres. The first would be the art of rowing. This “art sphere” deals with human factors such as motivation, team work, leadership, etc.—those human issues where there may not be a distinct right or wrong answer, but an answer nonetheless.

The second sphere would be the science part, specifically physics. Yes Physics. The same word that has freaked out an unlimited number of students and drove more of them to be English majors faster than the thought of Jane Austin could drive them away.

Over the past two weeks I’ve received several inquires about the physics of rowing, so I thought instead of addressing each separately I would post this. I spent years studying the physics of the ocean. When I started I remember thinking, “Wow, this will be cool!” And for the most part it was. Really cool. But there were so many dry, boring, difficult parts that physics about drove me nuts.

The main reason was that the way it was taught and explained. It was removed so much from reality and kept in the theoretical world that it was hard to really like it and see how it applied to more than just a few experiments and line drawings.

But since then a day has not gone by that I haven’t used some of my physics background in rowing. And if you row, or coach, or just work on the equipment, it is the same for you, whether you know it or not.

Physics plays a huge roll in rowing.

Disbelieve me? Read on.

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