i did the conversion for the levin bzr twin pod brakes to and it is 6mm not 8mms i did them 8mm first and the discs would not fit on to the hub so had to shave 2mm of them. you can get 6mm spacers on ebay here is a link http://cgi.ebay.ie/Wheel-Spacer-6mm...470?pt=LH_DefaultDomain_3&hash=item1e64dffbce