Matt75
Thanks for the input Marty.
 
Peter - Yes, I am very mindful of weakening the wheel.  No harm in having a chat though.
 
Cheers
 
Matt
 

I had 5mm machined off the back of the mounting wheel centre on 13x7 hotwires years ago & no problems.
The inner face of the wheel centre still protrudes proud of the wheel 'webs' or 'spokes'
so there is no loss of strength. I wouldn't have considered it if the 'spokes' had been touched at all.
 
Cheers