They'll fit but may wobble a little. Wrap two to four layers of electrical tape around the area they will sit on to fill out the gap and form a non slipping surface. Then you won't need to tighten the snot out of them. Road levers use a ring that pulls the bar up to and jams against the frame housing so it's a lot more tolerant of size issues than clamp types like mountain bikes use. But the tape will help fill the gap a little better.