Originally Posted by Canker

That actually makes no sense and having used nothing but mtn bike shoes I've never once thought about why they all have 4 holes. 2 holes or 4 holes makes no difference to how far forward or backwards you can move the cleat. It is all in the slot. Maybe the metal plate would have to be longer to be strong enough to cover for the full movement of the plate if it only had 2 holes.