My thread seems to have been deleted, again sorry if this is now old news and redundant...I pulled a cheap sealed Shimano BB unit out of a Trek 860 Mtn. bike (maybe a mid '90s)and discovered it was the OPPOSITE of a normal BSC threading pattern. The drive side is RH threading and the black resin cup non-drive side is LH thread. I think it is stamped LN26, but don't have it in front of me so could be wrong...it's NOT a UN series, is a gray metal body with square taper spindle. This is the second unit I've come across like this, the other being an older Trek, too, but a road bike. Any help appreciated, and thanks to the guy who already responded to my first post asking about the number...i'll know for sure in a few days when I get back to the shed.