Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Is it easier to wait until the wheel is built and then change the bearing Mike ?, I don't know if the 550 is the same as the 750 but on the 750 the retaining ring is centre dotted to lock it in position, I took a fine drill and drilled out the centre dots , I'm not sure if there's another way but someone will say if there is .