Originally Posted by SkyDog75

While we're waiting on bottom bracket confirmation or measurement...



This doesn't make sense. You can't cut a French steerer tube down to another size because French steerers are smaller, not larger. French steerer tubes are 25.0 mm while Italian, English/ISO, and JIS are all 25.4 mm.

Even if French steerers weren't smaller, it would be a bad idea to convert to or from French threading because the thread pitch is slightly different. Italian, English/ISO, and JIS are all 24 tpi. French is 25.4 tpi (1 mm thread pitch). Because of the slight mismatch in thread pitch, you'd effectively strip the threads if you tried to change the pitch.