My understanding is for all practical purposes Bikescore = TSS... Its just trademark and mathematical calculations.... I just compared Bikescore to TSS in one of my recent workouts and Bikescore was 94 and TSS was 96.7.... Close enough for me...
Yes, Bike Score is the same as TSS. The only difference is that one uses a 30 second rolling average and the other uses a 25 second rolling average in the calculations (due to a licensing issues in Training Peaks WKO).
Also, I think that xPower is pretty much the same as Normalized Power (slightly different formula, but I think the same idea). One uses exponential smoothing instead of a moving average in its calculations.
Also, I think that Golden Cheetah version 3 (in development, but you can download a release candidate version) will start to use the terms TSS and Normalized Power to better align with more industry standard terms. I guess they sorted the licensing out.
The main difference between TSS and Bike score (and NP vs xPower) is how they handle the rolling averages. the xPower is exponential, while the NP is a rolling boxcar. Arguably, the exponential weighting makes more sense, but that's another matter. In any case, my observation is that xPower is typically a (very) few W lower than NP and Bike score is a couple of percent lower than TSS for that reason. Otherwise, they are (as others have said) functionally equivalent. Mike is right about GC3 having NP/TSS/etc.
The main difference between TSS and Bike score (and NP vs xPower) is how they handle the rolling averages. the xPower is exponential, while the NP is a rolling boxcar. Arguably, the exponential weighting makes more sense, but that's another matter. In any case, my observation is that xPower is typically a (very) few W lower than NP and Bike score is a couple of percent lower than TSS for that reason. Otherwise, they are (as others have said) functionally equivalent. Mike is right about GC3 having NP/TSS/etc.
I've found this to be true for short rides, but for longer ones > 2 hours, xpower < NP by about 10 percent. Bikescore also lower by around same margin.
Just to dig a little more into William's answer, because Np is a 'boxcar' average whereas Xpower is an 'exponential' weighted average, then if the power is very steady, both will give almost identical results. Conversely, if the power is changing a lot (and changing quickly) — think VO2 max sets — then the results will be quite different.
So, as most of our long rides in season are usually spending significant time practicing riding steady, in those circumstances I would expect that these results on those types of rides would be fairly similar.
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Also, I think that xPower is pretty much the same as Normalized Power (slightly different formula, but I think the same idea). One uses exponential smoothing instead of a moving average in its calculations.
Also, I think that Golden Cheetah version 3 (in development, but you can download a release candidate version) will start to use the terms TSS and Normalized Power to better align with more industry standard terms. I guess they sorted the licensing out.
http://www.thetallcyclist.com/2012/11/making-sense-of-your-powermeter-data-golden-cheetah/
I've found this to be true for short rides, but for longer ones > 2 hours, xpower < NP by about 10 percent. Bikescore also lower by around same margin.
So, as most of our long rides in season are usually spending significant time practicing riding steady, in those circumstances I would expect that these results on those types of rides would be fairly similar.