increased speed if I put in 5inch side twin fins in my thruster?

dumb question but who has gone with a 2+1 setup on their thruster/ modern twin increased speed? trade offs?

Might turn sharper, but not go faster.

Side fins are toe’d in, bigger would be more drag.

Small side, big tail might, but speed is up to the rider, not the board, as it’s too dumb to know what to do!

For what it’s worth,

Less fin less drag, better foil less drag.

I know guys that surf little rail fins and a tiny center on the longboards and the go like crazy. All the flat sided rail fins I’ve seen do push water when you’re triming in a straight line. I watched some twinzer longboards at the Lane today and they were going way faster than the single fin longboards and surfing circles around them too – so go figure. You take that big centerfin off the board and things get real free. I may sound crazy but twinzer longboards work great. With one big rail fin you won’t have the best placement toe-in or rocker but it’s certainly worth a try you better have great rails and rocker on the board though.

– attached fins are running on a 9’2"

    right now and it rips --

With the right placement and proper foil and rocker a longboard doesn’t need a center fin (-- oops?! What did I just say?

Don’t believe me – check out the west side of Santa Cruz sometime when the Lane or Indicators is workin’. They’re not for everybody but it sure is a snappy free ride.

Good surfin, Rich

On my 7’9" fun/mal, I use side fins 6" x 5.5" and no tail fin. Not for speed, for quicker turning.

On a short tri, different rules apply, unless you want to trim in a straight line.

How long is your board, and do you want to trim for speed, or pump for speed?