First off, how much is your seatpost extended? Generally speaking, if your seatpost is way out on your road bike and you're looking for additional height in your bars, your frame might be too small for you. The traditional quilled stems on road bikes can rise as much as 50 - 80 mm or even more on road bikes so I see no reason why threadless stems can't sit up just as high.......but kinda looks funny and weird with all those spacers.....and usually, the higher you go, the longer the stem needs to be...