Sunday, May 20, 2012

Commencement Bay Race 2012

I finished the side drive system yesterday and took it out for a spin at the Commencement Bay Race today. Just as I started pedaling I heard a clunk-clunk-clunk which I determined to be the right crank arm hitting the head of a bolt that was being used to prevent the chain from being too sloppy. It was kind of strange to me that it was happening as it didn't seem to be hitting when I tested it in my garage with me pedaling. Sigh...apparently the crank mount I put together flexes just a little too much, causing the interference. Anyway, it wasn't so bad that I couldn't pedal reasonably efficiently, so I decided to race after doing a couple of turns near the starting line and getting the feel of things with the new drive and dipping rudders.

I found the ratio was a bit too high for my liking. Even at cruising speed of roughly 7 to 7.5 mph my cadence was around 60 rpm. It could have been a little higher, but I was too busy keeping up with the other racers and taking photos at the time. The offset thrust was also quite noticeable in its affect on the direction of travel. The boat has a strong tendency to turn to port, regardless of my leaning to one side or the other. The conditions were flat, with very little wind. The propeller shaft was vibrating a little, but otherwise appearing to work well. The clunk-clunk was a nuisance, but as I said it didn't seem to be impeding my pedaling. The relatively slow cadence was counterproductive to attempts to try sprinting, so I stopped for a moment and switched to a somewhat smaller chainring that was on the crankset to see if I could use it to get my cadence faster. Unfortunately, the chain was far too sloppy and derailed. So, it was back to the large chainring. About 16 minutes into the race, and about 23 minutes after starting from shore one of the shear pins in the Mitrpak R-082 gearbox broke with a big CLUNK.

I drifted for the remainder of the race, taking photos of the racers as they passed by. The currents in the bay moved me at about .5 to 1 mph, depending on where I was, sometimes turning the boat around as I hit eddies caused by a distant river entering the bay, being countered by the tides and very light breezes. Eventually the chase boat arrived and towed me back to the start.

I am a bit disappointed in the performance of the gearbox. I was under the impression that it should have handled the loads presented for a much, much longer period of time. I'm planning on returning it to Mitrpak to have it examined and repaired, and possibly replace it with a R-081 though the rating is not much higher. The R-061 used in the Cadence has a much lower specification, so I am not sure why the R-082 failed. Both gearboxes are supposed to be configured to have solid than rather than roll pins as they were special ordered to have them.

Lastly, I tried inserting a sheet of Coroplast between the closed cell foam and the open cell foam layers in the seat pad. As the pedaling portion of the race was cut short I can't say if there is much of an improvement, but I think it was working better than without the Coroplast layer in distributing the load.

Lake Whatcom & New Drive System & Biking

I've been both busy and lazy since Jetty Island. I went to the Sound Rowers Lake Whatcom race with the boat still using the Involute crank and long crank shaft as I still did not have the new drive system mounted. 12.5 miles, and my posterior was extremely sore for days afterwards. The seat bottom cushion, though almost identical to what I used in the Cadence, was definitely inadequate. I think the seating position of the V15-6m is a bit more upright, and the seat bottom of the Cadence a bit more flexible.

For whatever reason, I had troubles keeping my heart rate above the low 140's after the first 1.5 to 2 miles. Anyway, I still was within seconds of my personal record for that race, which was probably set the year I drafted a fast OC-6 for much of the race. I think that the outgassing of the amas was part of the problem, breathing the fumes from them for the 1 hour 45 minute drive to the race. A week of drying in the garage (with a small ventilation fan running 24 hours a day) after varnishing was not enough to get rid of the odor, apparently.

I've also done a bit of cycling in the local hills and mountains in addition to my every other day indoor recumbent/upright workouts. It is interesting to compare my hill climbing abilities with those of "regular" cyclists. It seems that I am a bit stronger than most in that area on upright bikes, and not far behind when riding my recumbent - and we have some fairly competitive riders in this area.

The side mount drive is finally nearing completion. I had to redesign a couple of pieces for the mount, but at long last the cranks, chain and gearbox are connected to the prop shaft and propeller. I managed to prime and paint some of the pieces, too. I have not completed fabricating and mounting the strut, but that should be pretty quick once I get the hull mount for it in place.

I'm thinking of placing the propeller so that it is about 2 inches from the upper tip to the bottom of the hull.

The rudder is still an area that will need to be addressed since the central prop shaft will no longer be there to hold the lower end down. For next week's race I might just have to go back to the dipping rudders again.

Jetty Island Race

In April I attended the Sound Rowers Jetty Island race in Everett, WA. The weather was relatively balmy, the sun was out, and there was not quite the wind that had been forecast for the day.

I did my usual thing of pedaling and taking photos during the race, and getting quite a good workout in the process.

The turning is still nowhere near where I would like it to be. I guess I'm spoiled by the Escapade and Cadence with their rudder-directed prop wash, but turning around buoys as is common in these races means I have to take it wide - losing time in the process. I came in 14th of all the single person boats. It might have been 13th, but I got too close to shore at the north end of the island and the prop was hitting the bottom. It took maybe 20 or 30 seconds before I could get to adequately deep water, by which time a guy on a surfski caught and passed me. I am pretty sure the V15-6m cruise speed is faster than the Cadence. I would guess it to be about 0.5 mph faster or so for the same level of effort.

In 2009 while pedaling a Cadence I finished with a time somewhat slower (54 minutes vs. 45 minutes). That year I managed to lose the rudder on some rocks at the north end of the island and had to use a canoe paddle to keep on course. This caused me to slow down a fair amount as steering is not very effective when done from the middle of the boat. Still, I think I am a little fitter, so far as pedaling is concerned, than I was back in 2009. My every other day exercise for the past couple of years of upright and recumbent cycle exercise is a closer match than running up hills.
In addition, I noticed that right full rudder on the V15 tends to aerate the propeller. Left full rudder does not seem to have the same effect.

Here are a couple of links to videos from the race last Saturday. The person who took these videos was not an experienced videographer so there are not as many close-ups as would have been preferred. Still, the camera was mounted on a tripod so the images are pretty stable.

Leaving the dock:


Race start:

Lastly, here is the finish line video. Roughly half way through is where I cross the line.