i am converting an old GT mtb so a SS trail bike and i need to put some spacers on the Shimano freehub to line up the cog. i have heard of some people using PVC pipes as spacers or harvesting a bunch of spacers from old cassettes but i cannot find enough old cassette spacers at the LBS. i am trying to not spend any money on this bike if possible, so what can i use as a spacer that would be cheaper than buying a SS conversion kit?
if the PVC route works, what size inner-diameter pipe would work? i can take it to the hardware store to find out, but i would rather call ahead to see if they have any scraps of the size i need.