Wanted to share my experience with respect to FTP Testing, FTP Results and Observed Results on my CX bike and my MTB.
I recently completed the Ramp Test on my CX bike and scored a number of 253w (reached 337w on the ramp test). This seemed reasonable and inline with my expectations considering the poor season I’ve recently worked through.
Though I haven’t completed any of the TR workouts yet, I have done a number of outside rides on my CX bike and the IF/NP and TSS all seem to be inline with Perceived Exertion and observed HRs. So far so good.
My question comes from my experiences on MTB. Since completing the 253w ramp test, I’ve done two outside rides on my MTB which have caused me to question the accuracy of the Ramp Test number. The first outdoor MTB ride lasted just under 2hrs, and I ended up with an IF of 0.91, a NP of 231w, average power of 218w, and average HR of only 143bpm. High wattage relative to my 253w FTP and low HR relative to my max of 182bpm. The second outdoor ride (2 days later) was more of the same again lasting around 2hrs but this time with a NP of 233w, an average of 214w and an average HR of 153bpm.
Lots of numbers here but the trend I’m observing is that my wattage on MTB is very high for long durations of time relative to my FTP and my HR is fairly low relative to my threshold HR. I should also mention that the above rides were mostly on flat singletrack trails with minimal obstacles (lots of flow).
Has anyone else experienced this discrepancy between wattage they are able to put out on MTB vs. Road Bike? This is nothing new - I’ve observed this same relationship throughout the whole season and all last season as well. Thought I’d post here to see what other people’s experiences have been.
- yes, the power meters on MTB and CX are different units but both units are very stable in their readings relative to HR and PE
- yes, both rides were in the same location and completed in the same conditions
- yes, the obvious way to resolve this issue is to do another ramp test but this time on the MTB - I will do this eventually.