Ive been over them with a fine tooth comb . A few stones embedded but nothing on the inside . I only had two slow flats , the rest where instant while riding . As Vickster found out , the roads around here are not the cleanest I had been driving to RP for a ride but now the holidays are over the free parking will be gone and i'm not allowed in the park with the van so ill have to start taking the bike on the roads to get there .