I think that is the tough part is spacing because the dropouts have largely stayed the same though maybe a better freehub/driver with a better spaced hub might work out?. But say a cassette like this would be pretty cool: 10-11-12-13-14-16-18-20-22-24-26-28-32 (maybe with some better tweaks because they might be needed for better gearing) I would love something like that on my road bike for sure.