fitness paddling: exercise, train, race by kayak & canoe

In the next post, I will try to summarize my experience with the Nucleus 100. I understand this kayak much better after reading Phil's comments.

I have paddled the Nucleus 80. It can't be compare to the Thunderbolts as they are based on different design criteria.

The Nucleus is 3 feet shorter than the Thunderbolt. The Thunderbolts are optimized to reduce wave making (displacement rate) at higher speeds. The Nucleus has been optimized to have minimized frictional (skin surface area) resistance at race speeds of 5 to 6 mph. ( A social multisport racer's pace.) Given the Nucleus's 17 ft length and an 80 kg paddler this hull has some serious issues with wave making at higher speeds, due to the displacement volume over the shorter length.

I have tested the Nucleus 80 and found this to be just the case. If you push it over 6 mph it's a big wave making machine. It's not a kayak you want to use for sprint racing. Sisson claims it's faster at lower power inputs, which is an oxymoron statement. What he's really saying is that the hull is reasonably easy to keep moving at it's natural hull (low) speed. Fit paddlers will find this hull frustrating, as it will generate waves at higher speeds, or in shallow water, making it an energy vampire when you need to go fast.

Sisson says he scaled the Evolution to get the Nucleus, and flared the hull above the waterline to provide secondary stability. Sisson is a gifted kayak builder and I take nothing away from him, but scaling is risky and not accurate. The displacement load (paddler weight) of the Evolution is I believe about 70 kg. The Nucleus 80 is 3 ft short and designed to carry at least 10 kg more weight, so must have either a wider section or deeper displacement. (Or both) This means scaling from the longer, narrower Evo is hard to imagine. He could have only taken the most basic of proportions from the Evo, but this to my mind still does not work, the design criteria is too different to allow scaling.

Sisson's logic in designing this kayak is sound, if people used his logic when racing. Mostly though people think with their imagination, rather than their logic, and imagine just how much better they would be if they had a faster kayak, not one optimized for their skill and fitness. So in NZ the Nucleus was never a big hit. The Eclipse, Eclipse XL and Total Eclipse by JKK really dominate the market where the Nucleus is pitched.

I've been working on my own "beginners" multisport kayak for the USA. The design is based on getting a faster kayak, that does not turn into an energy vampire at higher speeds, yet has some good initial stability for the novice not to be scared to use it. My first kayak is optimized for 65 kg paddlers. Yes 65 kg, it's for women and lighter men. It's being molded right now and I'll be testing it very soon.

The Thunderbolt baffles me somewhat.

Regards

Phil

Related posts:

• Sisson Nucleus 100, a Multisport Kayak from New Zealand - Part 1: Pictures
• Thunderbolt-X Kayak in Rough Water - Comments by a New Zealand Adventure Racer
• Outfitting Thunderbolt Racing Kayak - Tiller Bar Footrest and ONNO Gas Pedals
• Outfitting Thunderbolt Racing Kayak - Sliding or Guerney Gears Bumfortable Seat?
• Valley Kayaks Rapier 20 and WSBS X-par Missile: Can I Fit My Butt into a Narrow Racing Kayak?
• WSBS Thunderbolt-X Racing Kayak Arrived to Colorado

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