Diadora shoe sizing.

[HillSlugger]

I usually have good luck with 42's. I tend to have a wide foot so I bought my new Astro MTB shoe in men's size 42. The length was perfect but I needed to reduce the volume with an extra insole. Now, they are perfect. So, I'd say the length is true to size.

BTW, I love these new shoes. I'd been using Shimano MTB shoes but what I'd been looking for was something like a road shoe that is walkable. The Astro is exactly that. They sell the same basic shoe as both a road or mtb shoe, the difference being the addition of a raised surface around the perimeter of the sole that keeps the cleat off the pavement. It was exactly what I was seeking.

[Julibird]

and I think that they run maybe a half size small. On the other hand, they are racing shoes. Overall, I'm happy with them and they're kinda sexy. Cool buckle.