I saw this on e-bikes.org.
?As we said, it doesn?t take long for most hub drives to warm on steep hills, but they cool down quickly. A two- to five-minute break is a fair amount of time to let it get back to proper operating temperature. But if you start to get errors on flat ground with minimal load, you may have a separate problem which you should consult a bike shop about.?
?As we said, it doesn?t take long for most hub drives to warm on steep hills, but they cool down quickly. A two- to five-minute break is a fair amount of time to let it get back to proper operating temperature. But if you start to get errors on flat ground with minimal load, you may have a separate problem which you should consult a bike shop about.?