The spars in my Monokoat Big Stik 40 are hardwood. I received it about a month ago. It must be about Stik number seven for me. My first few were the Jenson kits back in the 70s and 80s. It’s a great design that you never get tired of no mater how long you have flown RC and how good you are at flying. But on the other hand any and all ARFs need a lot of checking out before you assemble them or you will be very sorry. The Big Stik 40 is closer in sized to the original Jenson kit than the Big Stik 60.