Mike wrote; > > If you make a seat-and-footpeg frame and mount it on three supports > (statically determinate), then put appropriate strain gauges on the > supports, you could measure the net direction of all forces and > moments on the kayak due to the paddler. Yes, and it would be something that could give immediate feedback while testing different stroke mechanics. Might prove very useful. > > However, this would not give much info on the paddle itself. True enough. It might, however, suggest the merits of specific stroke mechanics when imposed by the paddle geometry. Not sure this would make the effort worthwhile but interetsing nevertheless. Coliin wrote: > If you fail to replicate that complex motion (be you a > tank test dummy or a novice paddler), then they don't do very much very > well. I think most researchers understand this kind of thing. For example the paddle testing and stroke mechanics testing done by Plagenhoef, Mann, Kearney, Jackson, Brown Sanders and Kendal among others clearly shows they understand this type of thing. When you merge the two with tank testing such as in Locke and Brown's study then you really start to gain insight. (or rather, I should say, they started to gain insight). Just because a person wants to know how paddles work does not mean he/she doesn't care how humans work Sorry to blow my own horn but I suggested this in my articles in Canoesport Journal from over a decade ago and showed how it might apply to tank test results. The problem has always been , "How can we test objectively?" Unfortunately, as good as people are for telling you how they feel they just don't seem very good at telling you anything quantifiable with accuracy or repeatabiliy. If I know how much lift or drag or thrust or whatever a paddle produces at a wide range of angles of attack etc. then I can merge that knowledge with films of paddlers in action to see how the two work together. > and my argument is the only way to > test the validity of an analysis of the fluid dynamics/mechanics of a > static > paddle in flowing water or a paddle stroked through air and water would be > through a comparative methodology (combined or not with an analysis of the > bio-energetics) investigating real paddlers proficient in the use of their > paddles. Well, suppose one hundred expert paddlers confirm the validity of the tests and another hundred expert paddlers do not. What would you conclude from that? I faced this problem decades ago. No two experts could agree. >Another analogy - Knowing about the fluid dynamics of a disembodied > swimmers arm would tell you what? yet small changes in the complex motion > of > that arm result in great changes in swimming performance. I think this reveals a difference in thinking. Some seek to understand how paddles function and apply that to how paddlers can use them best. Others seek to form opinions based on experience and apply that to how paddles should be designed. At least with objective testing we can evaluate the results and critique the test methods. I no longer have the courage to tell a young, strong and potentially sociopathic paddler he doesn't know what he is talking about :) Anyway, I don't think anyone ever died from either method. This discussion has proven useful to me because it reveals how paddlers think about such things. In my book I have greatly expanded the chapter on paddles to include not just the theory of paddle function but the perceptions of paddlers. The key element in that being how a paddle designer (or builder) can make a paddle that will please people. So, thanks to everyone for their input. If have some opinions or thoughts that you did not want to post for public consumption you can send then to me personally. I really don't have time to discuss points with too many people at one time but I do make use of the comments. Cheers John Winters *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************
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