i don't understand

That board isn't for us on the east coast. I don't have any problems with the bonzer, I don't buy the asym or mismatched fins though.

That board may be highly evolved for a specific wave or the C Bros were glassing on whatever they had at the shop. It's cool to see art imitating life kinda like the marine iguana or the blue footed booby. They might thrive in their environment but outside their evolutions are a hindrance and the animals will probably die. This board may thrive at predictable point breaks but will be limited in most conditions we see on the EC.

Big wet monster, I think you have been drinking the barry snyder juice too much. If you're having trouble going frontside or backside, a board really won't help you that much. Gonna have to hit on the "It's the indian, not the arrow" cliche on this one. I'm not saying the tail/fin fusion doesn't matter. I just think you bought the wrong board for the way you surf or you need to learn how to surf the board the way it was designed.

 

I think of it this way... in the simplest terms... because I'm a simple thinker:

Single side runners are typically 3" high with a 10" base, and roughly triangular in shape. So if you measure the area like this... 3x10=30, divided by 2 gives you 15" of fin area.

On a five-finner, front side runners are typically 3 3/8" high with a 4 1/4" base. Doing the same math gives you about 2.6" of fin area for the fronts. Rears are always bigger, running about 2 3/4" high with a 5 1/4" base. Fin area equals about 7.2". Adding the area of the font and rear fins together gives you about 9.8" of total fin area. But we all know that the double runners are much less triangular than the single runners, adding a bit more fin area than half the squared area of the measurements. For argument's sake, lets say the curved leading edge of the double runners adds a third more area... 1/3 of 9.8" is about 3.2", added to 9.8" gives you a generous 13" of total fin area for double side runners.

Bottom line: Single runners add a whole 2 square inches of fin area per side, giving you a significant amount of added drive when compared to double runners. The cost? Less responsiveness... making the double runners looser.

In the asymmetrical setup, this gives you quicker response on your heel side, where you need it due to the lack of leverage you get from your heel when compared with your toe.

 

Ahhhhh thanks LBcrew! I just assumed that the 2 side runners on a 5er had the same surface area as the one side rubber on a 3....or if there was a difference that the 5er would have more surface area.

So here's a question LBcrew. Let's take the asymmetrical out of the equation just for a minute. Does a 3 fin bonzer have more drive than a 5 fin bonzer? I assume you'll say yes judging of your post above. So I'm going to follow up with asking why/how?

Like I said, I'm sold on the bonzer idea. I'm actually planning on getting a bonzer very similar to this one, minus the asymmetrical shape. When trying to decide between the two fin set ups I thought the only difference was in responsiveness. Because the concaves are the same, I thought the drive would be the same....since That's what the concave do. Direct water flow through the fins to create drive.

Just looking for some science/math to help me understand why/how a bigger side runner would create more drive than 2 smaller. BWM said that to so I'm guessing there's something Im missing. I think you may be able to help me understand what's going on there

 

Keel rudders have a feeling to them that is nice on the frontside. Lots of drive and still able to pull the board around. All has to do with ability to leverage your foot vs leverage your heal (not very easy to do on the heal)

 

Heale.

 

One of the central concepts of the Bonzer design is that the side runners, which are set on the edges of the concaves, act as an extension of the concave. More fin area makes for a "bigger" concave, adding drive. There's also the concept of the fins adding a kind of "thrust" (in the physics meaning of the word, it means forward force, in the direction of motion) when the board is put on a rail... when the opposite rail and fins are out of the water. Water coming diagonally off the bottom of the board in the form of spray through a turn hits the inside of the rail fins, which are set at an angle so that the force of the water, when deflected back toward the tail, puts an equal but opposite forward force on the fin. Here's a writeup I did on the Bonzer bottom a few years ago, which one of the Campbell brothers read, and emailed me back saying I pretty much nailed it:

Bonzer Bottoms: ...in the early 1980s, the Campbells introduced the Bonzer 5 Fin, which split the single side runners into two smaller, more elliptical or keel shaped fins, which were separated by a narrow channel, or “flute,” with the trailing edge of the outside lead fin slightly overlapping the leading edge of the inside trailing fin. Typically, the 5 Fin version used less cant on the side runners – about 18 degrees or less. The center fins were typically 6-7 inch center box fins. The side runners were about 4¾ and 5¼ inches along the base, with the rear set of fins being the larger of the two. This updated version met with great success for more than another ten years, when the addition of the elevated wing was introduced to the design. Part bottom design, part rail design, the wing began low on the rail, but as the tail slowly pulled in, the wing elevated off the bottom edge of the rail, becoming slightly fluted, ending around the trailing edge on the rear side runner. The wing added lift at low speed, bite and hold on steep sections, and pulled the tail template in when on a flatter, faster plane.

Although today’s Bonzers incorporate a number of finely tuned revisions, and include a wide array of variations, the purpose of the design remains largely the same. By the Campbells’ own account, the Bonzer was, and remains, “a simple, low tech approach to getting high tech results.” The concaves manage the flow of water under the board very efficiently, channeling water out the back of the board in an effort to create greater speed and drive. The low aspect side runners dip in and out of the water easily, limiting turbulence and drag, while providing superior edge control, increased drive through turns, and blazing down-the-line speed. In addition, the designers contend, the side runners help harness wasted energy by deflecting water coming off the outside rail back, toward the tail, when the board is put on a rail. This rearward deflection water theoretically adds forward momentum to the board, helping the board hold speed through turns. The Campbell brothers contend that, overall, the design is geared toward minimizing entropy – loss of wasted energy that could potentially be conserved and changed into forward motion.

 

bonzers by campbells were out there long before early 80's - 6 or 7 years.
thats all; not goin nowhere w/it...those guys also make good omelets.

 

Yes they were... I deleted that part, (see the ... at the beginning of the post) which came before the 5-finner part, because it made the post too long. Three-finners were the first generation of true Bonzers as we know them. But before them it was the "shortboards" of the time, just with deep double concaves. The fin array came quickly after that.

 

Thank you man that's what I was missing. I wasn't thinking of the fin as an extension of the concave. Duh. Now the add drive makes total sense. Thanks for taking the time to post that. Gave me that "ah ha!" moment. Now that asymmetrical design makes sense to me.

The only knowledge I have on bonzers is with limited (2 months) experience on my 5er and from reading the surfer forum or CB site. Never saw any discussion on the difference in drive between the two. You have opened my eyes a bit. Now I'm pretty damn intrested in trying a 3er

 

Take the Bonzer design out of the equation for a minute . . . I ride an asymmetric fish that has a single keel fin on the front side and two side bites on the backside. BWM described my experience with it exactly. But I'm not such an experienced surfer that I can pinpoint the effect.

 

bought my first at islander surf shop 1976. second one same shop 1978. they were all the rage surf fashion-wise
at the time and had the added benefit of performance. sold it for a hot buttered i just had to have....

 

I want an asym badly. The guy who is on here (SI) that used to shape for Windigo that designed this I believe...

https://www.youtube.com/watch?v=SlAv1soob4A

pretty cool but I can't jive with that center trailer....

 

I will build you one. Cheap too.
And I can assure you, it will be asymmetrical, whether intended or not......

 

Barry Snyder posts on here. Here are his asyms.

http://www.barrysnyderdesigns.com/asymmetrical-designs.html

 

Do you think you'd have trouble selling a custom asym after you got bored with it?