PedalTheOcean.com

It was a perfect weather day today so I got the record boat out to Elbow Valley community lake and ran some test with the new short flexible shaft and free hub:

• #1 flex shaft, small rudder, freehub, 150 watts = 11.9 kph
• #2 REPEAT of #1 = 11.8 kph
• #3 REPEAT of #1 = 11.8 kph
• #4 100 watts = 10.3 kph
• #5 200 watts = 13.2 kph

All of these speeds are almost exactly as per Ricks predicted speeds so this is very good news.


The spring steel shaft felt good - about the same as the stainless shaft I had on before. My speeds were about .1 kph faster with the smaller shaft diameter and length.

The other good news was the freehub that I coupled to the shaft worked very well. It allowed me to coast without pedaling whereas before, when I stopped moving the pedals, the prop would stop also and cause drag. However, it did nothing to change the feel of the normal pedal action and I found that I missed not being able to pedal backward to clear weeds from the prop or to go in reverse. I don' think that the weight or complexity of the freehub is worth it for the record boat. I don't plan on coasting at all anyhow. Here is a video of the freeprop spinning:


I've been waiting for decent weather, so I took the opportunity and packed the boat up and went to Glenmore reservoir to test some longer, straighter runs with some disappointing results:

• #1 1 km out and back = 11.1 kph
• #2 1.3 km out and back = 11.1 kph
• #3 1.3 km big loop = 10.9 kph
• #4 .8 km loop, NO RUDDER = 11.6 kph (10 kph wind)
• #5 .8 km loop, BIG RUDDER = 11.1 kph (10 kph wind)

The reservoir is VERY dirty because of the high water flow and flooding this year. At one point near the canoe club I went through a large patch of branches, logs, weeds, etc. I had to pull weeds off the prop and prop strut and there may have been some weeds on the rudder. I didn't count this run because of this. The runs that I did count were in an area that didn't have any visible weeds and there were not weeds on the prop or rudder before or after runs.

So why were my long runs at Glenmore so much slower than at Elbow?

Is it possible that at the small Elbow valley lake I am taking advantage of a counter clockwise flow in the lake? I doubt it because I don't really ever notice any kind of drift when sitting still.

My rudderless run at Glenmore was very close to the speed of the rudderless run at Elbow if I subtract .2 kph for 10 kph winds. Also so was the small loop big rudder run. The only difference was that the initial runs were either straight or a large loop. This makes me think that my slower speeds at Glenmore are due to the straight line route or very large loops that I did. Perhaps the boat is more efficient if it is making a small, constant left hand turn.

To confirm this, I need to get back out to Glenmore (or some other large lake) and repeat tests with various loop diameters and directions. Here is an updated speed table: