Originally Posted by Bike_13
3. 8s cog spacing (between cogs) is tighter than 7s, so an 8s Shimano cassette (remember there were no clusters) IS NOT 1/7th wider.
Well,then why is it that when you put an 7 speed cassette on a 8/9 hub body there has to be an additional 4.5mm spacer to take up the extra width.