I did not spend enough time on Pete's Cleveland road data reported yesterday, to notice that there are indications that the Kirkham road asphalt gives a calibration constant that differs from Cleveland road asphalt by a fraction comparable to one whole SCPF (ie 1.00102).
Here are Pete's data presented in the same format of my contribution to this thread posted 7 July 2008 at 22:06. I have taken The Cleveland Road concrete as the reference calibration course. A positive precentage indicates that a course on that surface will be found long when measured by a bike calibrated on the reference surface. + 100% would mean that the course would be measured by the bike to be long by one whole SCPF.
Kirkham asphalt 11000.78 + 44% smoothest surface? Cleveland concrete 10995.92 11003.2 reference calibration Cleveland asphalt 10996.8 - 58% roughest surface?
I hope I have got all the signs the right way round.
The point is that it suggests the Kirkham asphalt is greatly different to the Cleveland asphalt. Even if one allows for the fact that there is a lot of scatter in the graph of historic data which Pete first presented, I still think it would turn out that Cleveland asphalt is quite a bit rougher than the Kirkham asphalt.