what Kevin said.... Plus
You can get an idea of the power train losses by comparing rear-wheel horsepower and engine horsepower numbers.
Unfortunately this is rule-of-thumb stuff because neither number is particularly accurate or repeatable, especially once
the marketing department or racer's ego massages it. But, everyone agrees there is a difference, and its on the order of
10-20 hp as reported in the more reputable magazines, sometimes more. You can easily prove that the drag is nearly all
in the transmission by spinning the rear wheel with your hand with the bike in neutral.
So *I* wouldn't mess with the belt, unless there is an off-the-shelf solution. Even then its going to cost more than a
chain. Belts sometimes suffer from damage too. Millions of people ride with chains with very little maintenance.
Basically keep it slack and clean it once in a while and apply whatever lube is recommended. Harley racers usually
convert to chain drive BTW, and its not only to get better control of gearing.
This makes me realize there is a considerable benefit on an EV bike to running without a transmission. You'd have to
give up the belt for sure, but sprockets are cheap and plentiful so you can try a few until you get the ratio just right.
Can you get those motors to run in a wide enough rpm range to do that?
John
Kevin Caldwell wrote:
Both chain drives and belt drives can be 95%+ efficient, but both must
be adjusted and aligned properly. O-ring chains that most street bikes
will have as stock these days will consume more power than a non o-ring
chain. It is much easier to change ratios with a chain drive. Chain
drives require some slack, and the losses will be high if they are too
tight. There is not really any power lost because of the chain slack, at
least until it starts jumping teeth.
