Question for you roadies.

After talking to Dom at xotf i've decided to change the stem on my Raleigh from 130mm down to about 80/90mm. It's a quill stem, an ITM Eclypse. Can you open the bar clamp up enough to change stems without stripping the handlebars down? The ITM is steel so might be ok, but if i get an ally replacement i wouldn't be too confident.