Hi

I notice that all hub motors weigh a massive 1-4 kg. Could someone explain why people don't gear down high revving motors used by the model aircraft world?

For example, you can buy cheap 800W motors that weight only 280g.

I'm looking to develop a motor assist & energy recover system for my bike. For my slightly odd application, I'll only need bursts of power, say 1-2 seconds at a time. Would these lightweight motors handle this load?

Thanks in anticipation.