Keel Fins - why no toe-in and no cant on traditional fish.

Traditional fish have their keel fins set with no toe-in and no cant. Why is this and what effect does it have on the boards performance if there is a slight angle on the fins. Thankyou.

The traditonal fish is basically a gun shape widened up, with the straight rail line and flatter rocker, toe in would only work while riding the board very flat. Fish draw a line and take up a lot of distance during a turn, so configure the fins to work with it not against it.

The traditional fish flew down the line on clean glassy waves, this was due impart becouse of the fins pointed stright! ( remember tow boards, the fins are stright ). the same board does not work so good in crappy conditions, however if you were able to change the tow toward the nose the same board would be loose and spontanise, remember Buttons and Larry Bertalman. That was 1970 - 1980s this is 2000 !! Adjustable fins fine tune your surfboard to the conditions of the surf !!! So, why no toe in ? We didn’t know any better, and the fins were glassed on ! Aloha , Clyde Rodgers

In response to the original question. Keel fins and the Twin Fin Fish. The Twin Fin fish was invented around 1971, no one had ever applied cant and toe-in to fins at that time. The application of cant and toe-in and its popularity started in the mid to late 70’s. However, that original Twin fin fish with no cant or toe-in for the fins actually had alot going for it. Any twin fin fish by design would be very gyrating and lack down the line speed, however the early 70’s fishs got around this through design. By having a straight rail line instead of curved,turns were more drawn out instead of a short turn radius then run out of gas. The fins being keelish and set straight in also contributed to drawing out turns enabling this style of board to ride bigger surf than its length and two fins would have normally dictated. Consequently, you could really lay one of these down on its rail, and hold a turn and project down the line. Negatives: were that they could be tracky in certain situations, as in riding on a train track and hard to turn…if you didnt have a good one.

The tri fin V-bottom I shaped at Bahne and Channin/Diffenderfers factory in 1968 had toe in and cant in the set up.

Actually didnt Bob Simmons have a twin fin with toe in and cant?? However, when did it become a standard?? the Bonzer?

So according to that guy these boards only work in glassy lined up conditions. how come some people love them when its choppy windswell

Rob, you are right, Simmons boards had a toe in of an 1/8", no cant though. If you check the archives you’ll find the Simmons board Paul Gross shaped for me. It has twin fin boxes set in straight. After some experimentation with fins without toe in we ended up using very small fins (4 1/5") with the toe in shaped into the foil. It not only increased turnability tremendously but also went fastest that way… and I mean really fast! flo

Great timing for this topic I just got my blank and my lis fish keel fins for my traditional fish. So what happens if I put little tow in on my keel fins. I would like the extra turning radius but how much speed will a 1/8 inch tow in sacrifice? Has anyone tried this? I spied a fish in SD with wooden keel fins and it didn’t have any tow but it had a little cant. Thanks sr

toe in with longish keel fins, I dont’ want to especially bite this topic. But let me add, that the purpose of a keel fin is to draw out your turn, the purpose of toe-in is responsiveness and shortens?? the turning arc?? ( am not sure,but makes sense , since it makes initiating turns quicker and easier). However, toe-in over the base length of a keel fin, is going to be quite a drag. Moreover, with toe-in or more of it, your creating in the board more of an inherent need to pump it and promote more fin/rail release as you go down the line.

And when you look at the width of the tail of some of those fish (17inches)I think you would already be getting fin release as it is.

Great info, so I’ll keep the original premise of the keel fin no toe longer turns with speed but what about using a bit of cant on a keel fin. Will this produce better performance like the boards I saw in San diego. There is a least one shaper who thinks so.

no toe-in but ‘cant’ should enhance full rail driven bottom turns. See it as a positive-positive.