Alex Simmons/RST said:Let me make this simple for you.thehog said:Alex Simmons/RST said:Power was measured at the crank arms and at the ergometer load device. A motor would result in different power readings. They were not different.gillan1969 said:Apologies for not going through all the pages but did Swart check for a motor on Froomes bike before the test?
For argument sake let’s say he did have a motor during the test.
Crank has Stages so would measure the “strain” applied by the motor, the wind trainer is providing the resistance and is measuring power produced from where? The force of the roller, with resistance? He wasn’t using a standard ergo/jig. Which means a motor could be used depending on the type of motor & where it was placed.
If there was a motor then it could power the rear wheel without any force being applied to the cranks.
Power at the rear wheel is measured via an electromagnetic brake control device - it measures the torque and rotational velocity applied to the trainer's roller.
IOW if there was a motor, then:
Power at the rear wheel/trainer's roller = Power of a motor + Power applied via the bicycle cranks
Since the power measured at the rear wheel was the same as the power measured at the cranks, the contribution by any motor (assuming this hypothetical device even existed) was therefore zero.
I don’t think he had a motor, that we all agree, however the rear resistance was controlled at a set level, it wasn’t measuring his power output per se. You really only had one independent measurement of power which came from the crank arm.
The sub-maximal testing undertaken by Chris Froome required him to ride on his own bike connected to an ergometer that controlled the power independent of cadence. The test started at 250 watts and increased at a rate of 25W every four minutes. This test was done twice — once under ambient conditions, and once under hot and humid environmental conditions.