Originally Posted by
Duragrouch
Yeah, except, to mod as wanted with a 9 tooth cog, you can't just mount on the freehub body typical for an 11 tooth high, you need one of the newer freehub bodies designed for 9 tooth. Someone on here says some have the same "standard" interface with the hub, but swapping out a freehub body is a big pain, though perfect time to clean and relube the wheel bearings because the axle has to come out. But at least you shouldn't need a new hub.
It's possible to get a higher gear ratio by going with a larger chainring and then either go with a freewheel (or cassette, whichever is the case) such as an 11 to 32 if it works with the small 16 inch wheel. Or use a double chainring setup and get a wide range gearing that way. There are always solutions to every challenge.