Originally Posted by ItsJustMe
So how well would this fluid-based transmission shift at -20*F? Not very damn well, I bet.
There are some automatic transmission bikes around and I don't like them. Not knowing when the bike is going to shift can do bad things to your legs and knees. CVT probably not so much but I'll believe high efficiency and good cold shifting when I see it.
I don't believe the transmission is fluid based. There have been some hydrostatic transmissions but the NuVinci is all mechanical.
This is not an automatic transmission like the new Coast set from Shimano, rather this is a manually shifted hub gear with a continuously variable transmission. If its easier to grasp, think of it as having hundreds of gears with very small differences in gear ratios.
The claims are for high efficiency and apparently they are atleast in the same range and a hub gear. I'll have to wait to seem some independent tests or first hand experience before I make judgment there. There should not be any problem with cold shifting, though it is possible that efficiency may suffer more a colder temps.
Craig