Yes they can. I took my off of my Street Glide when I installed my lowers. I still got wind, so I wanted to re installed. In the mean time I put chrome lowers on plus put the black bells on. I taped off my chrome deflectors and painted the upper part black to match the black bells. I didn't know if they would hit the lowers, so I installed after the paint job and had no problems. Works super great. May now take off again and have repainted by a professional since they look so good on the bike.
Just a plug for the fork mounted deflectors. I bought this same set off of eBay and they are awesome! I've tried everything for wind buffeting and these are the only thing I found that worked. $80 shipped is a steal. I paid over $100 from eBay.