Join Date: Jan 2007
Location: Dover, NH
Bikes: rigid 29er moto, s-works stumpjumper fsr,black fixie,masi roadbike, ugly old hardrock commuter
External bearing cups(such as GXP interface) require a highly specific distance between the cups in order to work with the cranks. The spacers are necessary in order to achieve this distance. A 73 shell would simply require less spacers. He has all the spacers on the non-drive side anyway, so removing them wouldn't change the chainline. OP get some new cranks or adjust the rear chainline if possible. BTW have you tried sighting down the chainring with the rear cog installed? 8mm off sounds excessive.
Last edited by frankenmike; 11-20-13 at 09:30 AM.