Sorry typo, 53/38t; smallest that can fit on a 130mm BCD. I actually prefer the Hyperglide teeth-profile vs. the earlier Uniglide. The different teeth-profiles and ramps actually do shift without any slipping or grinding. Shimano actually had a 7-spd Hyperglide freewheel for a while. The top-cog was a slip-on one with an outside lockring; similar to the freehub cogs.