Long travel times.

You should always take a short ride before you calibrate.

You do bring up an interesting point about travel time between the measurement. Hence, if one takes a long ride before the post cal that could help. However, what happens if you need to make an adjustment. You then would have to go back adjust your course.

As for how long of a ride you have before the measurement from the cal course, that is something I would try to avoid. I really can't put a number on this, but my guess would be 30 minutes.

Hi Steven,
I measured a half marathon course a little over 2 hours from my calibration course and my pre calibration (6:35 am) count was 4434 and my post calibration (6:21 pm) was 4433 so only a difference of 1 count.
I agree with Pete on having to go back to the course if you need to make adjustments would be fun but I knew I would not get and split details till a later day so if I had to make adjustments I could do it then also.

That was would not be fun.

This is why I recommend putting down a couple strips of duct tape on a straight stretch near your car: When you arrive at the course to measure, ride your bike a bit, just to acclimate the tires. Then, put down a piece of duct tape. Ride 1000 clicks, and put down another piece of duct tape.

When finished measuring, ride the "reference course" and see if you are still at 1000 clicks. If so, great! If not, make your course adjustment accordingly.

Do at least two rides of your reference course before and after, to make sure you are consistent.

Calibrating cool & early then recalibrating in the hottest part of the day is ideal. Riding a few km is NOT going to warm up your tires if ambient temps are falling: PV = NRT & rims and spokes contract with lower temps. If you have reached the time of day when temps are dropping, that many km time delay may be fatal as in ooops! I have to drive back 50 miles and lengthen the course. Before leaving a course in that situation, explain to the Race Director that he or she may need to "move that nail some" for you later. Another strategy is to make several calibration courses in your area so you can conveniently recalibrate before finishing marking the course as evening temps start falling.

Thanks for the comments.

Sounds like having the cal course a long way away could easily be a problem under certain circumstances such as big weather variations or if you were not planning to revisit to make any adjustments. I would hate to get home and do a post-cal with a huge difference and left scratching my head....

The reason I asked was I had the impression from reading some posts that it was common for people to have a home calibration course (under 5 mins from their house). They would use that before and after. In between that may be some significant travel times and then potentially quite different conditions. It saves setting up calibration courses, but sounds like not always an ideal way to go.

Another solution is to measure a new calibration course near the far-away course to be measured. It's easy if you have a partner. I've recruited strangers (for $10.00) to help when alone. Pete Riegel also published a solo cal course layout procedure. I think it pushes the envelope a little, especially for a new measurer.

I use the solo method even when I have somebody helping me. The advantage of holding the end of the tape with a nail is that, as Pete says, you always know what the "guy" at the other end is doing. It is nice to have a second person there to help move the tape around though.

I am a big supporter of laying out a calibration course close to the course being measured.
My solo method is very simple: I bring a plank of wood with an eyelet screwed in one end. Drive my car over the plank, then fasten the tape measure to the eyelet with a plastic fastener. Measure the segment, then repeat, repeat, etc. Using the zip tie allows you to nail the zero point at the beginning of each segment. Plus, my helper weighs about two tons and he doesn't move!

A 200' or longer tape will save a lot of time.

I use a certified 100m steel tape for this.

If you're traveling 2-hours plus from home to measure a course you should be pulling a new cal course near where you're working. I traveled a lot last year to measure courses 10+ hours from home. The first thing I do when looking at traveling is see if there is a cal course near where I'll working and do some leg work. Usually I'll contact the measurer of record & get some details. If I decide to use their cal course I'll perform a verification measurement of it first. In 2 cases when doing so I found serious errors with a cal course (which were brought up to the regional and corrected). If there is nothing close enough for use I'll always pull a new one. It takes a lot less time to pull a new cal course than it does to make more round-trip drives to correct errors.

Brandon, I agree with what you are doing. Nice job here.