Originally Posted by
riva
Nothing I can really help with on the original poster's questions, but my mom has a 90's shaft drive bike.
How many speeds?
The Sussex drive is listed working with the Nexus/Alfine 3/7/8. I don't know about the 11??? So one should be able to get better gearing ratios.
Flex? Where? Maybe frame design? Shifting differently from a chain bike, one may just have to get used to it, but plenty of people have been using IGH bikes for more than a half a century.
Nonetheless, chains are very efficient.