Originally Posted by
steelbikeguy
I'm not sure that a flex wrench is required, but it might be handy.
I've been using a 12 point combination wrench, and can't recall any large amount of effort or frustration.
It also depends on the saddle. If you're using a plastic base saddle, most of those have enough clearance to reach the bolts with a combo wrench from the side. But if you're using a leather saddle with deep skirts, like the Brooks Professional or Idéale 90 or 92, you can only really reach those bolts from behind the saddle, between the rails, which makes using a combo wrench tedious.