The hoops are 51 mm Diameter and reading blogs the ideal bottom hole to allow for movement is 55mm
Started by drilling with a hole saw to 50 mm, however I didn't want to drill with a standard hole saw for 2 reasons first is its a 6mm drill going in a 10mm hole so ahs the potential to go out of line and second didn't want the drill to take any of the powder coating off the chassis as its was going though .
Hit on the idea of putting some 6mm stud bar instead of the drill and wrapping it with adhesive tape to make it appear 10mm.
Worked like a treat .
hole saw with the modified centre ( after drilling 4 holes ) |
first hole done |
second hole note slightly out |
again came up with an idea got a 12mm bolt and wedged it in some adhesive which had a diameter of 55mm ( eventually ) .
home made tool (note the back hole is smaller 44mm) |
tool in action |