I reshaped and foiled 2 Rainbow Fins a TK Flex and Rusty Flex, used a hand held black and decker sander, a bastard file,and hand wet sanded. These will go in a 2 plus 1 speed egg shape TK is about 6.73" and RF is 5.78" with 5" bases with a little rear flare. I wanted to post this cause I was happy with the results. But yet to water test it…
The fundamentals of this "reshape" was for a new custom speed egg which I will post in the future by Steve Coletta. In words he explained I was on the right track, the idea of deucing the base on the center fin to thruster like dimensions could really loosen up the board - could make for some tight radius turns without stressing the control factor by forcing the tail to release - withe narrow base and moderate depth. the surface area of the three fins - if we we could calculate the area of such a curved perimeter as a fin template -should add up to about the same surface area as a 4.5" deep pure thruster set. Rearranging that surface area into a deeper center fin with smaller site bites ( ht. 3.57" base 3.91") will provide stability on deep and fading bottom turns. This set up should bring function to lined up point breaks as well as larger surf with lots of of room for sweeping arcs. I really like the flex fins as a center fin from a previous well surfed Coletta speed egg, there are not many flex fins available out on the market under 7" , only one I found is by Rainbow - Rusty Flex. "Break your Trim!"