I built up a winter road bike a couple of months ago and have been using it for commuting ever since without any problems. A few days ago I went on an all day ride and afterwards took the bike to clean but found that the front caliper (105 sidepull) would not move on one side. I haven't had this problem before so I tried dismantling it to clean it but ended up stripping the hex bolt on the right (where the seizing is occurring). I've tried greasing it, WD40 and pounding it in anger to no avail. Any ideas?