Paddle slippage and stability

[josko]

I've been experimenting with Lendal Xrange 750, 700 and 650 paddles, trying to find something to replace my Ikelos and Cyprus. Here are some findings and surprises to date:

The 750 is a bit of a bear for me. it feels wonderful with a light, fast kayak (P&H Bahiya) when covering ground. I can feel the relative lack of slippage anchoring the blade in the water - it just 'feels' efficient', and I seem to get a few tenth's of a knot over the other paddles. My 4.5 kt cruise just works well.

However, I have to be very careful not to pull on the paddle too hard, or I start pulling/straining things in my forearms. I had the same issue with the Ikelos in early-season paddling - it would take me about a month before I could stop worrying about hurting my forearm tendons.

The 700 is a nice blade - I can feel the additional slippage and feel I'm working marginally harder at the 4.5 kt cruise; this blade reminds me of the Ikelos.

The 650 has, for me, a frustrating amount of slippage, and I can feel the difference from the 700. It's noticably harder to maintain 4.5 knots. On the good side, I don't have to wory about hurting my forearms with it, and it might be the ticket when paddling loaded boats long distances, i.e. camping.

And now the surprise part, that the post title refers to: I'm MUCH more comfortable in rocks and tideraces with the 700 than with the 750. One would think that the added area would provide that much more force to move the boat tightly in conditions, but the lack of 'yield' i.e. paddle slippage, really impacts my stability in rough water. It's as if i want the paddle to be slipping through the water to get a maximum bracing effect. The 'plant it and it's there' effect of the 750 somehow feels MUCH less stable than the additional yield I get with the 700. Similarly with a draw stroke in rocks - I'm not sure what it is - perhaps as the blade yields, I continue to position it to dynamically give me the directional pull. Whatever it is, the 700 does it a LOT better for me than the 750. Would anybody know what I'm talking about here? Why would a larger blade feel less secure in tight quarters and rough water?

Just for completeness, the 650 works for me in rough water, but I prefer the 700. Only time I would opt for the 650 would be early in the season or whenever I'm worried about my forearms, and perhaps with fully loaded boats.

FWIW, I've also been messing with shaft lengths, but that a subject for another post.

[Doug]

Josko,

Most likely the 750 has too much surface and resistance for your body size. Too much stress for the forearms to maintain a cadence over a long period of time unless your form is right on and your in top paddling shape. It's true that the the larger surface will give you more bite but at what cost. You will fatigue faster and lose finesse in the rocks where you need it most. The manufacturers suggest a heavier paddle in the rocks and surf to protect it from breakage but personally, I would lose the quick response reaction a lighter paddle affords me.

You can only get so much from the smaller size in this group but then again you are not expecting as much and psychologically give in to the resolve of not achieving your fastest pace.

Proper form plays a big roll of course and from time to time it's a good idea to work with a professional to adjust any bad habits that may have creeped in. It's been a long lazy winter so this paddler is spending an hour and a half one on one with Ben Lawry later in the week. I should be good to go after that.

The new Lendal Storm seems to be an exceptionally well designed blade in the 650ish range. It gives you an efficient bite of a 700 and the finesse and quickness of a smaller and lighter paddle. I love the strait shafts elliptical shape too. It makes it easy to correct your grip by feel when your mind gets disoriented. I do feel that Werner produces a nicer quality finished product over Lendall but they are still a relatively young company under new ownership. Sorry I'm drifting off subject.

No paddle will do everything as no one boat is best for all purposes. Keep the paddles you have. In time you will gravitate towards one over the others but admit it, it's fun to have these kind of problems.

Doug

P.S. Andy (inverseyourself), I hope this answered your PM to me earlier this week.

[leong]

A few points to add to Doug’s excellent advice.

Because we lose efficiency when a blade slips we may conclude that larger blade areas are more efficient. That's true for a machine (or an Olympic sprinter), but there are several mitigating factors for the rest of us. Here’s why some blade slippage is OK.

Firstly, increased blade area means increased weight and that corresponds to more effort, especially for the non-propulsive blade side.

Secondly, a larger blade makes it awkward to handle the paddle and restricts how close to the hull one can stab the paddle (that increases the energy lost to propulsion in the form of a force trying to turn the kayak; i.e. a turning moment).

Thirdly, blade size affects paddling cadence. Hill’s equation indicates that the maximum force a muscle can produce decreases as the speed of contraction increases. Noting that power = force times speed, there is some ideal speed (ideal cadence for paddling) that maximizes the power output from muscles. A higher or lower cadence from the ideal cadence reduces efficiency. So, if you’re not an Olympic sprinter, the blade size should be chosen to obtain the ideal cadence, even at the cost of some slippage.

Finally, it should be noted that paddle thrust (drag) squares with velocity. So doubling the velocity increases the thrust by a factor of four. That’s why paddle boarders can move so fast just using their hands (they move their hands fast and get a lot of thrust). Perhaps that’s one of the reasons that paddler’s using skinny GPs do so well.

-Leon

[EEL]

Since I am not familiar with the paddles, I looked at their website and noticed the 750 is not mentioned. So perhaps as Doug and Leon have noted it was just too big to be useful for most folks and dropped. As to why it makes you feel less stable in close quarter combat, can only guess that perhaps it is too big/gets "stuck"/shoved about in the water and that prevents/makes more difficult your ability to dance with the water and that results in a less stable feeling.

Ed Lawson