Originally Posted by
TimothyH
Just use mountain bike shoes.
Many manufacturers make MTB shoes identical to their road shoes.
MTB shoes are certainly an option, but they're not quite identical to similar road shoes. You sacrifice some sole stiffness when choosing a MTB version of a road shoe.
Compare the Specialized S-Works 7 road sole (stiffness index 15.0):
to the very similar S-Works Recon MTB sole (stiffness index 13.0):
That SPD mounting plate and slots in the sole make it hard to maintain the same stiffness of the road sole.
There's also the weight penalty, of course (about 100 grams a pair).