Not imaginary. I have two, grey anodised. I weighed them both and they came out at 450g +-2g. I know this because when I built my burls, I weighed everything to satisfy my spreadsheet OCD.
For reference, these were bought in October 2012 from BLB.
Fair enough, but the ERD hasn't changed... if yours are lighter and you say thinner inside, then they should have a lower ERD than the current ones (not higher). On all rims I have always measured 592
Not imaginary. I have two, grey anodised. I weighed them both and they came out at 450g +-2g. I know this because when I built my burls, I weighed everything to satisfy my spreadsheet OCD.
For reference, these were bought in October 2012 from BLB.