Originally Posted by glye

Right, thanks for the info. Given that this mechanic is experienced with this kind of bikes and the issues with reversing disks, it could be safe to do as he says. The disk will see less extreme forces on the Birdy than on the big wheel bikes it is designed for, anyway. So there could be a good enough safety margin here.



The disk is designed to have the right side contacting the hub. If you flip it, the left side contacts the hub. If the bolt hole part of the disk is thicker than the brake surface, the disk is now misaligned outwards by (bolt hole thickness) - (brake surface thickness). A 2 mm difference means 2 mm misalignment, for example. According to jackyharuhiko's mechanic, this is the case for the ice tech disk. But if the thickness is the same, it's fine, as with the Hope disk example, and with the original disk delivered with the Birdy. Those can be flipped.



This is true, and if they are willing to keep the warranty on it, it could be fine.

Personally I see no good reason for this kind of experimentation, but: Your bike, your decision