That hub motor weighs probably 40+ lbs to be able to do a fairly measly 8kW though, low RPM motors by nature are very large and heavy compare to a small motor r

That hub motor weighs probably 40+ lbs to be able to do a fairly measly 8kW though, low RPM motors by nature are very large and heavy compare to a small motor running through a chain or gears. A chain should last a very long time, as long as it's not overloaded and lubrication is used every now and then.