They are not just asymmetric, but are two totally different small wave boards which merge together somewhere near the middle. The two models we merged are the BT Twin Fin and Minion model. When we designed the board our aim was to have a board that had the flow and speed of a twin fin on toe side turns and the control and drive of the Minion model on the heel side. What eventuated was something very special! Incredibly fast and loose like a twin fin but much easier to harness in all conditions.
This asymmetric board goes equally well on your forehand and backhand.
“I think these boards are the best shaping I have ever done!” Billy Tolhurst
In the Autumn of 1970 I was working with Bob Cooper. There was only the two of us, both shaping with Bob doing all the glassing, sanding and finishing as I was still in high school. Surfboards were changing so quickly at this time that new boards were being outdated before they were even finished. We were making asymmetrical surfboards to see what different things did, plus we had the idea that you could benefit from having different curves frontside to backside. This was pretty common on the east coast of Australia at this time with lots of guys heading down this road looking for answers to the as yet unknown questions. We’d each shape an asymmetric board differently then Bob would laminate it, stick on a fin and hot coat it. A quick grind around the base of the fin and a foil job then down to the beach to try them out. We did this on a remote beach near town so no one saw us. One surf was usually enough to find out something relevant. Bob would then sand, pinline and gloss these boards and put them in his shop. We got to understand more about surfboards in those three months than I had ever known before, or probably found out since. We played with rockers as well as plan shape curves, foils, bottom shapes and fin shapes and their positions.
When Harley came to me a few years ago and started talking asymmetric I said pick two boards, tell me which side for each and I’ll get it sorted. Never really went any further because he couldn’t decide which board he wanted and where, but never stopped mentioning that he still wanted one. Early 2016 Harley bought it up yet again, I repeated my earlier statement but added small wave, instantly he said BT Twin Fin forehand and Blackhseep III ( Minion ) backhand, as Harley was travelling to the Gold Coast the next day I got him to buy a thick blank that we could get the thing out of, not quite knowing how to attack this I wanted plenty of room to move. He came back with it and wanted to do it instantly; like yesterday. I was laminating so I said you go and do it, It’s your board. When I’d finished laminating, I went to check it out and he had done a great job of joining the two planshapes and then we started fiddling and talking a lot about how to combine two different rockers and bottom shapes without detriment to either side. This is about when I took over and the Twinion kind of just fell into place. What we ended up with is a surfboard that surfs like a twin fin forehand with the positive feel and drive of a quad off the top and in cutbacks. When surfing backhand waves, the bottom turns are without any of the twin fin twice that some surfers have trouble with whilst snappy top turns and accelerating cutbacks are a reality. Overall a really fun board. The Twinion exceeded all expectations and when the Thunderbolt guys saw footage they wanted to make a couple. The Thunderbolt 5’10” and 5’7” Twinions in both Goofyfoot and Naturalfoot versions are the result. Billy Tolhurst