Chain vs drive shaft?

In order to give the kind of answer you seek, you would have to find a manufacturer who uses similar engines in both configurations (chain and shaft) in similar frames and test them.That would be BMW. They have decided there is a reason for either and do both very well.

The best I can tell you is shafts are for higher torque, long range, applications where smooth operation, low maintenance and quiet is the premium.

Honda Gold Wings,Shadows,BMW's and the positively obnoxious V Max. (I can say that I ride one).

Chains are lower cost to manufacture, to maintain,upgrade,adjust and can be made in so many ratios as to be the default choice.

No one can give you an exact percentage, or even a close estimate of the power loss. It can change with almost any variable on the bike. The design of the shaft drive, the weight of it, the motorcycle it's on. Almost anything can change the amount of power loss on a shaft driven motorcycle. The real question is what you want to do with the bike. If you want to race the bike or want it to be sporty and fast. Go with chain drive. It's cheap, reliable, absorbs road irregularities and stresses from hard acceleration, but will require cleaning and tensioning regularly. If your bike is a heavy cruiser or touring motorcycle, go with shaft driven. It's low maintenance, moderately priced and clean. High acceleration can cause imbalance in a shaft driven motorcycle, also will have a stiffer swing arm.

I had a V45 Sabre and the shaft caused nothing but problems. The primary reason for racers not to use shaft is for handling, the asymmetric trust makes a powerful bike a POS is corners.

Serious racers all have chains. Are you a serious racer? If not then you are traiding a tiny bit of unused power for low maintainance and a cleaner rear half of a bike.

I've 'enjoyed' them all!

Chains are PROVEN, but require reg maintenance & have a 'noise'

with them!

I've had shaft drive~ quiet-reliable & 'expensive' to repair!!

I now use a belt drive!

no noise~good reponse~low maintinance & a couple hundred $$

to replace!