- Oct 18, 2003
- Saline Michigan
Most of the parts between engine and rear wheel are there in both systems. Clutch, primary drive, countershafts, gears, dog clutches, most of the bearings, and so on. They have to be there anyway. There are no differentials in a motorcycle. The chain final drive has two pair of bearings while the shaft drive needs four pair. The shaft and CV joint add some pounds, and that is probably most significant on a racer. We are not talking race bikes, we are talking airplanes that kill us a significant fraction of the time when power is lost. So I vote for reliability on maintaining power...Bike shaft drives and extensions have a lot of moving parts between the crankshaft and the end wheel. A lot of bearings, gears, differentials, clutches, and all these add up. Look at the linked web page, it is a very realistic approximation and allows school students to calculate the losses and efficiency. There are even specs for every single mechanical piece how much efficiency is lost on each depending on the type.
Where are the specs and efficiencies listed for the internals? Where is the model? None are on the website you provided.Every loss will also depend on speed, torque, temperature and a lot of other parameters. Short story: look at the calculating model. When you'll get a chance to disassemble your bike shaft drive for service or oil change, note all the parts inside. Write them down. Look for their specs and efficiency loss. Add it up and you got the difference between crankshaft power and rear wheel power. Then seek an XS1100 chain drive.
Check out our tough Yamaha XS1100 Chain Drive Conversion
Or maybe they ditched the shaft drive because it was not up to the increased power of the engine once prepared for racing and the lightness was a bonus. The seller's of the kit do not cite advantages, just that they have it and it won a race 40 years ago.You see, people raced with your bike more than 40 years ago, because they understood the information I wrote about here and the thought of engineers. Some ditched the shaft drive and switched to chain drives to reduce losses and improve efficiency. Extra weight was reduced, even a lighter swingarm could be swapped.