So my girlfriend & I have kayaks that we want to take camping with us. I got a pair of new fold-down J-style roof carriers for them. However she has a Pelican sit-on kayak and the seat back doesn’t come off like mine does. We will be driving 2hrs on the highway & I don’t want her seat back getting bent beyond repair or ripped off. Should I use a strap to keep the seat back “folded” down, load the kayak so it faces backwards, both, or is it not even an issue?
I believe you answered your own question. Strapping the seat back down would negate any worry about wind resistance.
As would loading it backwards. I do both depending on the boat.
Along with folding the seat down and keeping it down with a bungee think about the strap that will now be lose that adjusts the seat back. A two hour drive with it flapping at highway speeds will put 100 years of wear on the strap.
Also because you are new to J hooks and all this make sure you watch a few vids on how to attach the straps around the boats and what safety lines you may wish to add.
Ive had my kayak for years but have used more of a cradle style carrier on my roof to where it lays flat. I always use 2 straps & 2 safety lines for each kayak even when only driving 5 miles.
For hers I’ll wrap a shorter strap around the kayak to keep the seat down & load it backwards i guess.