theres a guy on the touring forum using a motor hub on his bob trailer basically to help him out when the going gets tough (hills)
how does a fella go about getting one of these wheels with hub ,how will it work do you just flick a switch when you need it to kick in..
is it very expensive to build.and would it be very heavy when your not using the power .

Figure for the kit including batteries to cost between $400 and $600, depending on how far you want it to take you.
Most kits come with a throttle control.

Most of those kits have a twist throttle and a toggle switch. You can either twist and go, like a motorcycle. Or switch to pedal assistance mode, battery will drive motor while you are pedaling. With a better controller, it will has cruise cruise control so you don't have to hold the throttle.

emm very expensive think I'll just have to suffer on the hills so.
ah well not to worry thanks lads.