yeah have used them to carryout most repairs to bikes including stiff bb's. not easy but possible. usually clamp seat tube as close to bb as possible and go to town. (depending on frame of course.) failing that take it out of the stand but at no time on my cytech course did they say you could not remove a partially dismantled bike from the stand. i found that the tacx one became unstable when trying to undo the bb and worked best if you placed it up against a wall to stop you pushing it over. but most home mechanics wont try too hard on a bb. theyll take it to a shop where if they fuck it, they pay for it. thats my experience anyway.
yeah have used them to carryout most repairs to bikes including stiff bb's. not easy but possible. usually clamp seat tube as close to bb as possible and go to town. (depending on frame of course.) failing that take it out of the stand but at no time on my cytech course did they say you could not remove a partially dismantled bike from the stand. i found that the tacx one became unstable when trying to undo the bb and worked best if you placed it up against a wall to stop you pushing it over. but most home mechanics wont try too hard on a bb. theyll take it to a shop where if they fuck it, they pay for it. thats my experience anyway.