Correct, point is the dynojet says it is making more power, but it isnt.An eddy current dyno applies a brake against the drum and measures the actual power being used (electrical current) to hold the engine at a certain rpm.

 

Figure on the average, 15% driveline loss on these bikes, between the engine, and the wheel.
Scott

 

Well doggone it, can't seem to get it posted...

Scott, I'll send it to you, as you will be impressed.

 

RWHP is not actual HP, but it is the ultimate deciding factor on how a bike will perform. Just as lighter engine parts in your reciprocating assembly will help give you more crank power, lighter parts and less friction in the drivetrain will give you more rear wheel power. So if you took two bikes with identical engines, one can make more power at the wheels and it will pull away from the other. Lighter rims, pulleys, type of lubricants, etc. anything with a lighter rotating mass will translate to more power at the wheel. If 15% loss is average, a 100 hp crank engine will make 85 at the wheel. Start lightening up items and that could climb to 90+ at the wheel. That carbon fiber rim does help.

 

We're getting in a right muddle here! It is true that there are power losses between crankshaft and the rear wheel. However a dyno measures performance at the rear wheel, not the crankshaft, so those losses are taken into account. Rear wheel performance is corrected to engine speed, not crankshaft performance.

An engine giving 100 TQ on a bike with a top gear of 3.18:1 will actually deliver 318TQ at the rear wheel.