I just got some cheap road wheels (Forte Titans) and i want to put an old Shimano 8 speed cassette on them. The splines fit correctly, but the 8 speed cassette is too tall all stacked up. The lock ring won't engage the threads. Its about one spacer width too big. there is NO spacer behind the largest cog... i of course can't remove a spacer in between cogs... Whats going on here?