Thanks tbaker,
For the CF over the top, I was thinking it could be something like the full carbon soccer shoes that Nike came out with recently. Unless it was custom made, it would probably have to have some flex in it to adjust to your foot. Plus I was just having some fun.
As for the ankle brace discussion, cyclists need to have some natural movement in the heel area, especially when standing and rocking back and forth. However, to say that a cyclist doesn’t want any ankle support is a bit excessive. Most cycling shoes have a hard plastic cup on the heel to prevent too much lateral movement. You could replace this with a CF cup that is lighter, but allows just as much natural flex for the ankle. It would just depend on how thick you make it.