Blackhawk Zephyr, how much rocker?

I have the other specs, but not rocker. While it’s upside down on my car rack, it looks like it’s got at least three inches.



I haven’t tried to measure it while it’s right side up on the ground, that would require two or more people, at least that’s how it seems to me - it doesn’t sit flat very well. If nobody else has the Zephyr rocker numbers, I may try to contrive a rough means of measuring it.



Thanks.

Also, Zephyr seems very trim sensitive.

– Last Updated: Mar-23-08 11:48 PM EST –

Mine has the ICS two height sliding seat system and the handling changes significantly when the seat position is adjusted and can transform from very squirrely and uncontrollable to feisty and fun by sliding the seat aft several inches. It's a beast when the bow is too heavy and plowing.

Those of you with fixed seat Zephyrs, how far back from the outside edge of the bow is the front edge of the seat?

I'm 5'6" and 155 lbs.

Thanks.

Rocke
Measuring rocker is done differently by different manufacturers so results aren’t always what they seem. Especially, as in the case of a Nova Craft Supernova or Swift Raven, when the rocker starts form very near the center of the boat. Some boats, such as the Nova Craft Pal, have rocker starting only a couple of feet from the ends.

While it’s on your car park it as level as you can and position it as level as you can, then take any straight edge about 12’ long and lay it on the hull. Measure back 12" from the tips of the bow and stern then measure up to the straightedge. It’s rudimentary but it will get you pretty close.

Thanks,
I should be able to come up with a 12’ long piece of lumber to try that method.



Why measure 12" back from the tips of the bow and stern rather than closer to the tips?

how is “rocker” defined?
I’ve never thought about this before, but it’s not really clear what “rocker” means, quantitatively.



If you define it as difference in depth (when realistically loaded) between deepest point and cutwater at the ends, then you can measure it like this: Put yourself and your gear in the boat in calm water. Get a lucky volunteer to mark the ends at water level. Estimate where, lengthwise, the deepest point is. Take the boat out of the water and put it on a flat floor. Rock the boat back until the estimated deepest point is touching the floor. Measure the height of the marked points at the ends; those two numbers are the fore and aft rocker.



That’s precise, but it puts too much emphasis on the extreme ends. I guess a more meaningful measure would be the average depth difference between deepest point and cutwater at the ends, but that’s harder to measure. I say it’s more meaningful because it’s basically equivalent to the “missing” submerged area of the center longitudinal section of the boat, between deepest point and cutwater, relative to the submerged area of a perfectly straight-keeled boat along the same length. I suppose that missing area is really what determines the ease of turning.



Any other thoughts on how to define “rocker”?



– Mark

12" back from 4" waterline
A couple years ago John Winters posted on the ccr list that he had made overtures to other designers and manufacturers to standardize the measurement of “rocker”. For lots of reasons the idea never caught on.

I used the 12" back from the deck tip because that’s what some builders are using. I’ve measured Nova Craft Supernova and Pal, Wenonah Argosy and Wilderness and Bell Prodigy X this way and my numbers matched theirs. So that might be how they are arriving at their figures, too.



The Nova Craft Pal has most of it’s rocker within 3 feet of each end. The Supernova however, starts rockering very near center, on a flat surface the boat “teeters”. The Wenonah Wilderness has about 6 feet of flat in the middle then the rocker builds gradually to 1-1/2 inches at both ends.

BTW. speaking of standarization, is the US the only remaining country not using metric system? I’m trying to match nuts to bolts on this Raven I’m rebuilding and it driving me nuts.

I think I found the trim sweet spot.
It seems to handle pretty well where I’ve got it now. It’s now very easy to turn, pretty easy to keep straight and weight shifts and leans work pretty well and it pretty much does what I want it to do.



I haven’t measured this location of the seat, but I’ve been told recently by someone very familiar with the boat that the front edge of the seat should be about 4" aft of dead center of the boat.

3mph for 3 miles today in the Zephyr
at comfortable cruising pace on a 1 mile course around the curvy shorline of the local city park lake using a 50" Wenonah Black Jack carbon bent shaft (ZRE relable?) paddle. 50" almost seems an inch or two short with the tractor seat in the top slot. My 56" straight shaft ZRE seems an inch or two too long. I would have done another lap or two if I’d had the time. The winds were steady at about 10mph, but I was mostly sheltered from them for about half of the course. It seemed to handle in the wind from all directions.



I know that 3mph isn’t a very fast pace, but it sure is a fun pace in the Zephyr on that lake with all the turns while following the shoreline and messing around with the boat control and the boat’s handling characteristics.



Happy paddling.

Zephyr is a great boat
I put many happy miles on my Zephyr before I started paddling with a dog. I was almost too big and heavy for it at 185 lbs or so, but with a light thwart bag the total load was fine. I took a freestyle lesson in it; it worked great. It was so quick in acceleration and so good for cruising speed that I sold my Flashfire…the Zephyr was hotter for my type of use although the Flash is a much more capable freestyle boat. I used to hit and switch with a nice light straight Grey Owl Freestyle and the boat would really cruise…faster than most tandems.



It’s a bit tender for beginners but otherwise I think it’s a truly magical boat.



At 3 mph I think the boat requires almost zero paddling effort!

Hit & switch does work well in Zephyr.
In addition to using the 50" Wenonah Black Jack bent shaft, I also like using the 56" ZRE straight shaft for a while, but it’s either too long or the blade’s too wide, because it tires me quicker than the 50" bent shaft.



I have a lot of learning to do with single blading solo canoes, but the Zephyr is a lot of fun to learn in.

Zephyr rocker
I have an 88 BlackHawk Canoe catalog. From the side view, rocker seems ~!2" bow, ~1" stern carried out to a point under the paddlers fanny.



No rocker dimensions were published, but Phil was an early convert to John Winter’s suggestion of differential rocker.



The extreme carryout, is reminiscent of the Chestnut Prospector.



Dana Grover and i paddled the first Zephyr on our way to the Sawyer BWCA event, fall 87. It was a fine little boat, fast and responsive, that had an unerving tendency to take water over the stern quarter when heeled to the rail.



All in all, the best bottom Phil ever designed. I miss that man.

what is carryout?
Charlie,



Can you explain the term carryout? I’ve never heard it.



Also - is Phil gone? I bought a Combi 15’8" from him at a demo day at CanoeSport in Ann Arbor in 1992 and I enjoyed meeting him. Only $875 at the time, with amazing quality and the nicest ash/mahogany contoured kneeling thwart I’ve seen.



Finally, I have no idea of actual rocker specs but it sure seemed like the ends were pretty high in the air (esp the bow) when you set the boat down on a wooden dock…it seemed like the boat had significantly more rocker than a Merlin II.



I also remember taking in water many times when playing with the boat…another 1/2" or inch of freeboard would have helped me.


Measured about 3.5" total rocker today.
I layed a 12’ aluminum pole along the keel of the upside down boat and measured a total of about 3" to 3.5" combined at 12" in from the ends of the boat. That’s right on target with what Charlie posted above.



I’m not sure how to tell how much of that is at the front and how much at the rear.



It sure looks like more rocker than that with the boat just sitting on the rack upside down. Looks can be deceiving.



Thanks for the advice on how to measure the rocker.

More rocker than Keef Richards.

Rocker Disappears Over Hull Length
Had a Blackhawk Zephyr and Starship gunnels down on racks. Both had the same amount of rocker but the Zephyr has the rocker extended over a shorter distance.



Of course this means the Zephyr is more playful than the Starship. Unfortunately, a person could make the statement “they have the SAME amount of rocker.” This would be horribly misleading…



Just curious. Does the Zephyr have similar characteristics to the original Bell Wildfire composite?