I rode 12 miles of rough singletrack this past Mon. with just running shoes on my ATAC xs carbons( not much platform) after realizing Id left my riding shoes at home. a couple blocks will not hurt. bunnyhopping will be interesting but doable. a good pair of sandals is about as stiff as begginer riding shoes at any rate. you may also find some SPD type sandals cheap in the very near future too