Data Presentation

Pete,
Dynamite spreadsheet!

That really shines a lot of light on the Protege method. It should be part of the "quickstart" blurb.

One suggested improvement; I really had to study the sheet to see where the 1.001 came in.

One question:
You show 141.85, 141.86 and 141.87 turns. I guess that is skilful eyeballing. It sounds tough to estimate within .82" (82 inch circumference of wheel/100) as the contact point of a tire.

Steve

The 20 marks on my rim are 4 or 5 inches apart. It is pretty easy to eyeball to the nearest 1/5 of the interval between marks, which represents 0.01 revolution.

I'll work on putting the 1.001 into the spreadsheet. Watch this space.

The 1.001 has been added to the original posting.

Here is an example spreadsheet for the case where one rider uses an electronic counter and the other uses a conventional Jones/Oerth counter.

I have said it many times over the years but I will say it again for new entrants like Stephen, who are not set in their ways: there is no need to convert any counts or revolutions to meters or inches during certification and therefore no need to use spreadsheets or measuring tapes. The official method of processing results gets the right answers, but it is an inelegant way of doing things. Just getting the right answers was not good enough for my maths teacher of 55 years ago. He only gave full marks if you used the most elegant methods or proofs.

Take the following example of calculations in certification of a 5-km course with 1-km splits. (Mile splits are only slightly more complicated.) I assume that tire pressure or temperature increases only slightly from beginning to the end of measurement:

400-m calibration crse: 191.57, .55, .58, and .58. Ave: 191.57

Calib factor = 191.57x1.001/0.4 = 479.40 rev/km = 2397.02 rev/5km

The first ride was for 2397.02 rev to locate a temporary finish line. In the second ride, splits were located at intervals of 479.40 rev with zeroing before each split. The temporary finish line gave a reading of 479.20, so the second ride determined the final finish line.

Although calculations are very simple even when factoring in tire pressure and using mile splits, I have programmed my hand-held calculators to do them after entering the calibration rim readings in hundredths of a rev (ie: 57, 55, 58, and 58)

Neville,

Maybe the spreadsheet is not needed for the guy who does the measuring, but it, or a hand-arranged simulacrum, is certainly needed when sending the data to a certifier for review.

When I get data from a measurer, I expect everything to be clear and complete. I would find your abbreviated version less clear than a fully spelled out version.

Pete:
The my above presentation of results is not in the least abbreviated. It only seems so because it is not swollen with a lot of unnecessary numbers.

Neville,
I applaud simplifying things.

You said "there is no need ...to convert...revolutions...to meters, but in your sample calculation there is 479.4 rev/km

You also reference a calibration course of 400 meters. How do you get that other than with a measuring tape. That's all I use it for.

Stephen:
Of course you have to use a tape to establish a calibration course. Its from that point on when you do not need it. However, standard practice is to bring one out at the end of a measurement to make a "course adjustment". Note the 12-foot adjustment in Pete's example above.

Stephen,
Neville method is short and accurate, however it would not be the way to present your information to the Regional Certifier. The forms are there for people to use and Pete's spreadsheet will make it clear to the regional certifier that your work is complete.

The tire pressure thing is in the experimental stage and has proven to work, but the RRTC has not yet apporoved this.

Steve, I suggest you use Pete's spreadsheet when presenting your work for review.

Gene and Stephen:
Despite Pete’s reservations I believe my format for presenting results is simpler and clearer than the conventional way. For several years I sent results to Paul Hronjak for certification in this format on a slightly modified standard form, and never had any complaints. However a guiding principle in RRTC has been that each individual certifier has the final say on what is acceptable in methods and presentation, so the measurer must only use what the certifier finds comfortable.

However there is no reason why a measurer should not begin using the basic aspects of pressure monitoring as a valuable adjunct to the current conventional method of measuring. For instance, by setting pressure at the start to precisely the same value every time he should get precisely the same calibration factor each time, and this would be a check on anything going wrong. He could tell the precise moment his tire reaches equilibrium after pumping it up or removing it from a hot car. (No more “warm-up” rides.) The measurer would be alerted immediately to a slow leak and avoid wasting a whole day’s work. If he had a flat he could fix it and resume measurements at precisely the same pressure. The postcalibration would vet his procedure. Finally he would gain experience and confidence to fully implement the method in the future.