I screwed the 1x4 down but it didn't break just the plywood, it basically followed the inside line of the binding. The more I think about it, I sure am glad I added that 1x4.
If I hadn't added the 1x4, I bet you I would have done the splits.
I can just see what would have happened.
With my feet in the bindings & each foot having it's own set of wheels, there would be no way I'd have enough strength to keep my legs from sliding out, that could have been catastrophic.
If whatever doesn't kill you, only makes you stronger.
Then I am so close to immortality