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.
posted by Michael Lampi @ 12:26 PM
3 comments
3 Comments:
Mike
I'm following your lead and changing from the involute gearbox and inline shaft to a side mounted shaft. I had to remake the torque box as the bottom bracket is too narrow for the old one. Got hold of a 1:2 90 deg gearbox which will give me a 1:7 gear ratio. I'm going to use one of Ricks carbon fibre props and a 10mm dia aluminium shaft. Still finishing off the torque box so might be one or two weeks before I finish it and get it on the water. At the moment I have a small spade rudder mounted under the hull. Might change this as my aim is to be able to sit the boat flat on the beach.
Ian Cassell
Hi Ian,
At Commencement Bay last weekend I tried the side mounted drive for the first time. It worked pretty well, though with a 6:1 gearing my pedaling cadence was closer to the 60 RPM range than the 70-80 RPM range I was expecting when going at 7.5 mph.
19 minutes after starting the race the gearbox broke, probably due to a shear pin breaking.
I shipped it back to Mitrpak to hae them take a look at it. This one was special ordered with solid shear pins, and should have easily been able to take the torque so we are not sure why it failed.
Otherwise, I like being able to launch close to shore, etc.
Mike
Bad luck about the gearbox, its always at the worst time these things break. I've got a 1:2 gearbox from TEA transmissions, it has 15mm dia shafts. I'm going to use a 52 tooth chainring with a 15 tooth gear at the gearbox. This gives me a bit of scope to go up or down with the gearing.
Ian
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