Registered Forum User
Big Twin
Bikes: Ducati 749, Phil Read Replica, DD 620
Posts: 1,830
Join Date: Mar 2008
Location: Coventry
Mood: 2011 DD Class 'B' Champion
I can't see what your trouble is Scott!! You just need to measure across the two bearing abutments in the wheel. The easiest way to do that is leave one bearing in place, then measure from abutment to bearing.
You will want a 21mm bore in the spacer and O/D, 0.5mm smaller than the bearing inner race O/D.
Give me a bell if I have got it wrong.