I installed the chinook straps on my foil board and I think they are designed horribly wrong. You simply cannot lengthen them b/c the neoprene cover on the ends only stretches 2-3 mm at most. I'm not trying to get my ankle snapped in half on my first ride, or be able to only tuck my toe nails into the straps. Furthermore, an advanced foiler at my local uses cabrinha straps that were probably 2x as loose as mine. He laughed at my straps. Another guy told me the straps are really good.
All I know is these straps are not for me. Anyone know of real adjustable straps for a surfboard that do loosen like a twin tip? thanks.