I was switching my "S" spokes for "C" wheels today, I had to use my existing brake disks. The front ones were very tight, but nothing compared to the back one. I broke 3 allen wrenches and finally ruined the recessed heads on the bolts. I don't know what it would take to get them out. i finally had to drill them enough to remove the brake disk. Needless to say the old wheel is basically ruined. i called the dealer and talked to him and he suggested heating them. Just be aware of this problem if you attempt the same thing. Oh by the way the new bolts which I have to buy cost 4 bucks each and there are 6 of them. Insult to injury.......