fitting

I’ve been in the market for boots for a while, and it got me thinking. Why isn’t it a more common recommendation to try boots on barefoot? Without socks (especially padded snowboard socks) on, it seems WAY easier to feel how in contact/not in contact you are with boot liners. Thoughts?

Last year I got a pair of Niro boots size 11 used them for the year my foot would sometimes move in them so this year I got a pair of vans size 10.5 my toes are just touching but my foot is still sliding forward in the boot when I'm riding could this be fixed by getting good footbeds?