With the "right" pedals, most folks can be comfortable on a bike wearing just about any sandals, any shoes....I prefer to use BMX style pedals on all of my bikes. That allows me to ride with sandals, tennis shoes, running shoes, dress shoes, and my favs, skateboard shoes (comfortable for both walking and riding).
A BMX style pedal allows you to position each foot in the most comfortable position (and some folks might position their left foot differently than their right foot). They allow shifting the foot forward and back half an inch, or moving left to right half an inch, so that the stress pattern on the foot varies.
And, a large BMX pedal is as wide as my foot, spreading the stress over a very broad area. Many clip-in pedals focus all of the pressure and stress on a very small portion of the foot.
So, whether or not you will be comfortable wearing sandals may depend more on your choice of pedals than on your choice of sandals.
Last edited by alanbikehouston; 02-11-05 at 12:35 PM.