I have worked on 4 bikes which were apparently "designed to rub". Check for these common errors:

- Wrong B screw setting on the RD. The gap between the largest cog is 6mm and not "enough to clear". Common amongst Shimano indoctrinated mechanics.
- Wrong angle on FD and not the proper clearance between the largest chainring and the lower part of FD. I use a copper penny to set the clearance and never had problems.
- Set clearances and tolerances on FD first before the RD.
-Check proper chain length.
- Check cable set-up and proper length. Watch the kinks and sharp bends on the handlebars to the headtube/downtube bosses. Try the criss-cross configuration to lessen sharp bends (I don't know if this helps, but all 4 bikes were re-configured in this manner)


*make that 6 bikes...I will be working on 2 more this afternoon.