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We've made boats wider, can we make them skinnier?

Posted: Fri Jun 14, 2013 2:02 am
by sc-vapaddler
No, I don't mean in production. I noticed a while back a fad of putting longer thwarts in the canoe to make it wider (seemed to happen with PE boats) and more stable. My question is would the opposite (shorter thwarts installed) work or change the performance of the boat?
I have a Caption that has the standard thwarts installed, I'm curious if I could install shorter thwarts to make the deck skinnier. I also have a Detonator and I noticed that the gunwhales are closer together than the widest point of the boat (hull). I'm sure the caption is slightly wider just below the gunwhales, but what would happen if the gunwhales were significantly skinnier than the hull's widest point? Has anyone attempted/ done this?

Re: We've made boats wider, can we make them skinnier?

Posted: Fri Jun 14, 2013 2:13 am
by ezwater
I once spread a Tripper to get a shallower arch in the center, and along with a foam pedestal crammed between the center thwart and the bottom I got a bit more rocker and a wonderful pivot zone. Probably the best handling OT Tripper ever.

But I suggest being cautious. Maybe take your Caption in an inch and see what it does. On the Esquif, I'm not sure what you'd get. That pinched in shape at the top of the hull is for your convenience in reaching the water. Again, be conservative.

Remember that toward the ends of the boats, you may not need to cut entirely new thwarts. You can just shift them toward or away from the center if you want to widen or narrow toward the ends.

On the Caption, I might be tempted to go a bit swedeform by spreading the stern zone a bit, and narrowing the bow. My MR Synergy is swedeform to begin with.

Re: We've made boats wider, can we make them skinnier?

Posted: Fri Jun 14, 2013 2:29 am
by Flip756
I've paddled Dagger Ocoees with standard length thwarts and shortened thwarts. Both boats had the thwarts in the factory location. The pinched boat was shortened by about an inch and a half. It was twitchier, the transition from initial to secondary stability was noticeably more aggressive than the standard width. The boat felt faster and much less "friendly". That being said, I'm pretty sure I'd rather have the pinched version. It didn't seem as dry but the responsiveness and gained speed more than made up for any perceived drawbacks.
-Jacob

Re: We've made boats wider, can we make them skinnier?

Posted: Fri Jun 14, 2013 12:06 pm
by Silent Bob
My first OC1 was a Mohawk XL12. After paddling it for a while, I decided that it was a bit of a pig. After a few beverages one day, I attacked it with a hacksaw and shortened the thwarts about 2-3" and moved them around a bit. It made a huge difference in the way the boat felt. Easier to get a good, vertical stroke, quicker, and a whole lot easier to roll. It was a fairly round hull to start with, so I didn't feel like I lost much in the way of stability. It made it a much nicer boat to paddle.

Pulling in the gunwales will tend to arch the bottom of the hull a bit, and theoretically reduce rocker. It is possible to overdo it, so its worth experimenting a little. I would suggest removing the stock thwarts, then make up some "adjustable" ones out of some scrap wood. You can either gradually cut them down, or clamp them in somehow. Then you can tinker with the length and placement and test paddle to see how the boat feels. Once you figure out the length you want, make up some real thwarts and install them.

Re: We've made boats wider, can we make them skinnier?

Posted: Fri Jun 14, 2013 12:22 pm
by Todhunter
I pulled my L'Edge in about an inch. Flattens out some of the rocker, makes it a tad faster, and you give up a little bit of initial stability, but it is quicker edge-to-edge.

Re: We've made boats wider, can we make them skinnier?

Posted: Fri Jun 14, 2013 3:39 pm
by Shep
I took 1.5-2 inches out of an Ovation... completely different boat. A little bit faster, very edgy, turned on a dime.

Re: We've made boats wider, can we make them skinnier?

Posted: Fri Jun 14, 2013 10:30 pm
by cheajack
I have had two Dagger Ocoees that I pinched 2". Faster, more nimble even with a little less rocker. Tighter fit and much easier to get vertical paddle strokes. Waaaay easier to roll.

Re: We've made boats wider, can we make them skinnier?

Posted: Sat Jun 15, 2013 8:42 pm
by Mike W.
Downriver racers have been doing this for years. It reduces rocker, speeds the boat, makes it harder to turn & less stable.

Re: We've made boats wider, can we make them skinnier?

Posted: Sat Jun 15, 2013 9:39 pm
by TheKrikkitWars
I've finally got round to temporarily pulling/pushing my prelude to make it swedeform, it's been pulled in 2" at the front (with extra thwarts at 8" [7.5" wide] and 22" [16.5" wide] from the bow) the front stock position thwart is the normal width (24") and the rear stock thwart has been widened to 26½"...

It's lost an awful lot of rocker (almost half I reckon) at the front and gained a little at the back, I'll be getting to test it tomorrow, and will be taking a screwdriver and the stock rear thwart with me just in case. I'm hoping that by keeping the bit under my knees the same, and widening the back, it won't have lost much if any stability, whilst hopefully giving it more speed.

I'm not sure I'll be able to keep it like that permanently even if it's worked out well, as the hull is pretty beat up and I'd rather not over-stress it, whilst I can't afford a replacement if it breaks.

Re: We've made boats wider, can we make them skinnier?

Posted: Mon Jun 17, 2013 6:51 pm
by Oci-One Kanubi
Back in the early '90s I did that with a Mohawk Whitewater 16 (which any of us today would refer to as a lake boat).

I removed all the thwarts (except possibly the little carry-thwarts at the ends - I don't remember about them) and drew a lariat around the absolute middle of the boat. By tightening up on the bight to pull in the gunwales at the center I ensured a smooth transition from ends to mid (a cam-strap would have worked as well and been much easier to manage). Then I cut down the original thwarts to fit, and re-drilled them to match the existing holes in the gunwales.

It became a very fast Class II/III solo camper or tandem day-tripper.

Re: We've made boats wider, can we make them skinnier?

Posted: Mon Jun 17, 2013 7:45 pm
by PAC
I believe Mohawk had an adjustable thwart at one point in time. Aluminum with a screw adjustment. Anyone remember or have photos?

I've dow this to boats with both good and bad results....of course the outcome was not dependant on my skills! :-(

Re: We've made boats wider, can we make them skinnier?

Posted: Tue Jun 18, 2013 3:13 pm
by drrpm
I had a solo Caption that had been narrowed an inch or 2 but I didn't like the decreased stability so I made some new stock length thwarts for it. Its easy enough to give it a try and see whether or not you like the result.