I do the same on tour and commuting, but also wear synthetic briefs under the cycling shorts. I bring a few extra pairs of briefs which let me go a few days without washing either pair of shorts if I have to (on tour). I haven't experienced much chafing problems, but if the fit isn't right one could (lotion like "chamois butt'r" helps). The synthetic briefs don't weigh much, breath very well, and dry overnight if its a dry climate.

For "fitness" rides I wear the synthetic briefs under cycling shorts.