I need a miche supertype seat post for my fixed conversion. The problem is that my frame only accepts 26.4 mm seat posts and every supertype I've ever seen is 27.2 mm.

According to miche.it it's available from 24.8 mm to 27.2 mm. This kinda implies that there are more sizes available in between 24.8 and 27.2. If not I'd settle for 24.8 and some shims.

Could someone please help me find a small enough supertype? I've emailed miche several times but they won't respond. I've mailed lots of stores but noone can help me.