Rockefeller Trails

Jim I have a course that I am waiting on the weather to break also.
My question to you is how do you measure the trail part of this race? Do you have a calibration course on the trail? Also is this race run on roads and if so do you measure using 2 different calibrations course? Just planning ahead for when I have to measure on the trails.
Thank you for any input.
Jim

Jim the trails are actually crushed stone bridle paths. I don't intend to do any special calibration for that sections - my feeling is that if you ride slowly the difference is so minimal it doesn't matter. Maybe others can correct me on that.

I was just wondering because of question #27 on the Application for
Certification of a road course which wants to know the type of surface (give %) and than it says if your course includes any unpaved sections, please attach a detail of the method(s) used to measure such sections. I am wondering if anyone has laid out a calibration course on the trail or in this part of the country we call it the towpath and the road and seen what the difference is? I may have to try it this summer if know one has done it.

I am a little disappointed that no one made any comments on my question #27 on the Application for Certification of a road course.
Jim how will you or did you answer question #27 when you measured the Sleepy Hollow Half Marathon course? I am thinking you will have to have 2 different calibration courses if the distances are about 50/50 (road/ trail). Or if it is 10/90 (road / trail) a calibration course just on the trail. Also it will probably be very hard to make a permanent calibration course on a trail so now you have to lay out a calibration course every time you measure a trail (is this maybe why no one has made any comments).

I plan to measure out a calibration course on a rail-to-trail close to my home as soon as things warm up this spring. I will then do some calibrations on it and compare to calibrations on my usual paved cal course.
But it won't be very conclusive for the general case for many reasons. The two courses are in different locations. One has only a very slight incline while the other has a bit more of an incline. One will probably be a bit more sunny than the other. Calibration rides vary by a count or so from ride to ride. Eliminating this noise from the experiment would require a large number of rides, and this introduces the problem of a changing temperature during the experiment.
Add to all this the fact that there is no one definition of a paved surface and one definition of an unpaved surface. Mike Sandford has shown that calibrations vary even for two different types of paved surfaces. It's almost certain it will vary even more for two different unpaved surfaces.
It would be great if a large number of people did some experiments comparing cal constants for paved and unpaved surfaces. The best setup would be to find a location where paved and unpaved surfaces are side by side, similar to Mike's experiments on different paved surface types. But it's difficult to find that because usually the unpaved "shoulder" of paved paths isn't in very good shape.