Tech Tuesday is our feature here at the Stern Scoop where we plan to highlight some of the more technical aspects of some of our products. From line specs to how to properly rebuild a winch we hope to provide some fodder for the tinkerers and engineer types out there.
Today we’re starting with some detailed specs on carbon tiller extensions. We offer seven different types with rubber universals (there are some larger big boat extensions made of carbon as well from Forespar). From top to bottom we have the Acme Fatso, Acme Fatso Jr., JCD, Ronstan, Forespar Giant Stick, Forespar Big Stick and Holt Allen. I threw a quarter and a dollar bill in there for a size comparison.
We felt that the two most important measurable qualities of carbon tiller extensions were their stiffness and their weight. To that end we’ve crunched the numbers and come up with the following results. All the extensions measured were 48″ or the closest length the manufacturer makes (+/- 1″ or so). You can click on each product for more details like cost and diameter.
|Product||Weight (oz)||Deflection (inches)|
|Acme Fatso||7.7||1/8″ (Best)|
|Acme Fatso Jr.||5.8||9/16″|
|Forespar Giant Stick||6.9||5/32″|
|Forespar Big Stick||7.5||7/16″|
|Holt Allen||5.5 (Best)||7/8″|
We measured the weight of the extensions on a postal scale. To measure the deflection we supported them at both ends and hung a 26lb weight from the center point of the extensions. Kudos to Ian for developing this testing rig and doing all the deflection measurements.
While I think with more time and an engineering degree a more accurate testing process could be devised I think we’ve provided an accurate means by which to determine relative weight and stiffness for these extensions.
Grip and diameter are a matter of personal preference. Obviously the thicker extensions performed better in our deflection test and tended to be heavier (although the Forespar is actually lighter). The Holt Allen and Ronstan’s have foam grips and the JCD has basically a rope wound around the end which is then shrink wrapped. The Acme and Forespar extensions have a textured sandpaper like feel.
The picture above is of the Ronstan which obviously had a bit more bend than the others. The Ronstan is also the only tapered extension so that might be related to the bending.
Which one is the best? I think based on the numbers the Acme Fatso Jr. looks like the winner to be with the best combination of stiff and lightweight. I prefer the textured grip of the Acme and Forespar over the foam but again that’s more of a personal preference. If you want a larger diameter to hold onto the Forespar Giant Stick is a great choice as well.