Therefore, your existing 'mountain bike' shifters and brake levers won't fit on drop handlebars. All of Shimano's current (Alivio, Acera, STX, Deore, LX, XT and XTR) mountain bike shifters and brakes use aluminum housings and handlebar clamps. So do the ones made by SRAM. These cannot be widened enough to fit onto the larger road diameter bars. If you try, you will probably crack the aluminum housing. (I know, I've tried.) Even if you could mount them, the brake levers curve in the wrong direction.