I found a pair of gently used Sidi SRS boots for a price I can't pass up, my old boots have a tear so I figure it these will work, why not? The problem is that they are a size 9 1/2 and I know boots are all about fit so I'm not going to buy them if I have to squeeze my feet in. In shoes I can wear anywhere from a 9 1/2 to a 10 1/2 depending on the brand. In cowboy boots I wear a 9 1/2 comfortably. Also I can wear a alpinestar size 10 fine. I've heard Sidis run a little large so I think they will work but I want to be sure. Also my calves are a little bit large (they fit in a-star boots fine) so how far can the straps adjust? Note: None of the shops around carry Sidis so I can't try them on.