I'm looking at a new pair of road shoes, and I'm wondering what the difference is between carbon soles and fiberglass. In particular I'm looking at the Shimano R085 vs. the 131. The main difference seems to be the carbon soles.

Any other difference/advantage for carbon soles? The price jumps $50 for carbon soles.

The 131 are the bargain of the Shimano road shoe line up.

This is the first year that they have had a shoe at this price point with a buckle closure rather than with three velcro straps.

As far as differences the carbon soles have a lower stack height and are marginally stiffer and lighter.

I just picked up a pair to supplement my sh r-215's which were the top of the line when bought and can tell no difference. If you can do without thermoplastic molding and a black carbon sole get the 131's.

I'm looking at a new pair of road shoes, and I'm wondering what the difference is between carbon soles and fiberglass. In particular I'm looking at the Shimano R085 vs. the 131. The main difference seems to be the carbon soles.

Any other difference/advantage for carbon soles? The price jumps $50 for carbon soles.

CF composites allow you to make a thinner sole at the same stiffness. This allows for a lighter shoe and a little less stack height. Whether this means anything to you, and whether it's worth the extra cost, only you can determine.