I am attempting to make a bonzer style board. I stripped and reshaped an old longboard that I had. I have a couple of questons regarding the concaves and the fin placement.
The dimensions on the board are 8’ x 16 x 22 x 15 at the wings and 2 7/8 thick. Nose rocker is 3.5" and tail rocker is 3".
The picture shows where I have placed the double concaves. Does it look right or not? Should I make the concaves/channels longer? Do I need a single concave in front?
Second question, I would like to use a 5-fin setup. What about fin placement, how far up from tail? How far up should I put the center fin box? My weight is about 185 and I tend to surf off the back foot.
I would take the concaves up a little more, I talked to one of my neighbors a while ago and he rode one bonzer for like ten years or so and said the only thing he would want to change about it would be to bring the concaves up to like the mid point, and then put a single concave up from there. Scince you have such low rocker allready, I don’t think the single needs to be very deep, but bring it up to maybe a foot or 18 inches from the nose, just so it transitions well. I did a bonzer like before christmas and I still haven’t glassed it yet, but looking at it for that long I think my concaves now don’t start high enough. There’s another post about concaves but it’s kinda for a shortboard that’s on page 1 right now, but you might want to read through that too.
I don’t know about the five finners, but for the center box from waht I’ve read in the archives you should put the box at like five inches from the tail.
Hope I could help, but if you’re still wondering there’s a bunch in the archives on this that I’ve just constantly read through because I didn’t want to mess mine up…
These measurements came from a 7’2" eggish bonzer 5.
channels start 3-4’ from tail slight at 4 realy starting at 3. All fin measurements to rear of fin. center 6". next is 11.5 then 15.5,they used red x that comes with cant. Didn’t measure the depth of concaves but looks like approx.1/8. think I might have seen somewhere that you buy the fin set up and can get a template with them.