Mark:
My conclusions at the end of my last post were based on the assumption that the average calibration factor from a flat course, even if it did not correspond exactly with that from a sloping course, at least should fall somewhere between that found for downhill and that found for uphill measurements. However, I notice that your average calibration factor for the more flat course is much higher than either of the latter two from the sloping course. This seemed inconceivable to me so I decided to test my assumption.
I taped a 152.296-m course with a drop of about 10 m and found that the overall average calibration factor from two downhill and uphill rides differed from that found on a flat 400-m course by only plus 0.005%.
I note that in going from your more flat course to your sloping course you went from asphalt to concrete. Mike Sanford has stated that this results in a decrease in calibration factor, and Pete in his recent post indicated that his experience shows this decrease to be 0.06%. Your results show a closely matching decrease of 0.08%. Evidently, the newly discovered “hill” effect is really only the old road-surface effect!
Results from flat 400-m course
1. 191.68
2. 191.71
Ave 191.695 or 479.24 rev/km with no SCPF
Results from 152.296-m course with a drop of 10 m
1. 72.94 (down)
2. 73.04 (up)
3. 72.94 (down)
4. 73.04 (up)
Ave 72.99 or 479.26 rev/km or plus 0.005% from flat course