Need a smaller fin to go in my Fox 120. The stock 40cm fin is great with the 8.6 most of the time but but when it's really blowing or I go go down to the 7.8 it gets to be a handful. I'm thinking the Severne 36cm fin that comes with the fox 105 or maybe a tectonics raptor 36 or 38cm fin, I have the 50cm raptor in my fox 140 and love it.
any other ideas? No waves involved but nasty chop. I

38-40 too close even if one is beefier than the other. 36 should work well. Good practice to run small fins anyway ;) !

Sounds more like you could use a smaller board, a smaller fin can be overpowered fairly easy if the board is too big.

^^ Flip side is when its windy a long fin overpowers the board - railing up.

He needs a smaller fin for the windy days

Generally goes something like this,
light wind fox140, turbo 9.2 and 50cm raptor, when that gets to much I go to the 44cm Severne fin. When that gets to much I go down to the 8.6overdrive or I go to the fox 120 with either the 44cm fin if the winds got holes in it or the 40cm severne fin if the winds solid. By the time I'm down to the 7.8 I could be on a smaller board but as I don't have one and Don't see myself getting one in the near future I need a smaller fin.
I got slammed really hard a couple of weeks back broad reaching when the tail railed up, board took off then sail back winded. I don't to repeat that, it hurt