Calibration Course Measurement

In outline:

• Count out the substantial nails which you will hammer into the road, using a "club" hammer. Count one more nail than the number of steel tape lengths you plan use for the cal course. PK nails recommended.
  
• Hammer No.1 nail in leaving about 3mm clear of the road so that you can hook the tape end ring over the nail. Apply a 50N (5Kg) pull and check the nail is in far enough that it does not lean over at all ( or come out)
  
• Unreel the tape for the first length. Tension at 50N then let slack. Hammer No. 2 nail in opposite the 50 metre mark (assuming it is a 50 m tape) Remember to leave 3mm clearance so that you can later hook the tape end over.
  
• Now you need to tension the tape using one hand extended to the sitde while you are kneeling with your head over the nail and in a position where you can read the exact mm opposite the centre of the nail. You will find that depending on the crossection of your tape it will stretch probably slightly less than 10 mm as you apply 50N force.
  
• Write down the reading. For my tape it is usually around 49.992 metres. Now tension the tape again and check you have written down the correct reading.
  
• If you find it diffcult to judge the correct tape tension using a spring scale tied onto the tape reel with some string and tape. I find if I locate the harness at a suitable part of the reel I can just hold with my extended arm my scale which has a max reading of 5kg (a scale sold for fishermen cathching small fish!). Even though my eye is not above the scale but above the nail I can see quite accurately when the scale shows 5Kg applied.
  
• Put the tape reel and scale down on the road. Walk to the end hooked over the nail and unhook, Walk back to the reel, now pull the whole tape along the road, looking back and noting when the hook end has reached the No. 2 nail. Lay the reel down, walk back to nail 2, amd hook the end of the tape over the nail. Walk back to the reel and proceed as earlier inserting no.3 nail.
  
• Continue for the required number of tape lengths.
  
• Having reached the far end you now need to take a second measurement using the nails which are still inserted. Turn the tape round by reeling it in hooking the end of the last nail and walking back tio the last but one nail where you take the reading, then continue as before to reach nail no 1.
  
• If the two measurements agree, hammer the two end nails right flush with the road, and remove the intermediate nails.
  
• Do the corrections for temperature, and include correcting for the offset between the centre of the nail and the zero of the tape scale. I determine this by measuring with ruler or similar between the 10cm point on the tape and the centre of the nail when the tape is hooked over the nail. Include the correction once for each tape length. And make absolutely sure you get the sign of correction correct.

A past posting of mine said:

Jim Gerweck wrote in MNForum "Several years ago Pete wrote an article on laying out a cal course solo, using masonry nails. Maybe he can repost it." The articles in question appeared in Measurement News in May 1997 and January 1999. They may be accessed at:

http://www.runscore.com/coursemeasurement/

Also see this posting:

https://measure.infopop.cc/eve/...831034262#7831034262

Mike and Pete,

Thank you for the solo procedure and references.

I have volunteered to measure our small town's first half-marathon. The course is not to be certified but I thought that it would be good to measure it the proper way. So this is my first time at doing anything like this.

I have ridden a bike, seriously, for 45+ years and have spent a lot of time playing around with calibrating bike computers accurately. I had thought that my current bike computer would do the job until I realized that one-hundredth of a mile is 52.8 feet and also that one pulse per wheel revolution is not good enough. I then searched the Internet and found the USATF procedure and this great forum. I also ordered a Jones counter which arrived yesterday. Actually, Tom Riegel led me to this forum. Would Tom and Pete be brothers?

Thanks for the help.

Sincerely,
Bob Wemer
Grinnell, Iowa

Pete is Father

Tom and Stu (former Course Registrar) are the two sons. Joan (former Course Registrar and Columbus Marathon Race Director) is Pete's wife.

Family business.

Bob, if you need assistance in measuring the course be sure to ask Karl Ungurean. He's the Nebraska certifier but lives in Davenport. Great guy and he will be glad to help.

Thanks Jim,

I'm doing this as a volunteer for free. I have the USATF Procedure Manual pdf and just purchased a Jones Counter. The race isn't until June. I'm waiting for the city powers that be and a few local experienced runners to decide on the final course before I get involved. The course has changed several times so far. I'll also have a 5K to measure. The courses won't be certified.

My local bike shop owner is also on the half-marathon committee and thought that, with my cycling experience and experience with calibrating cycle computers, I would be the ideal choice to measure the course. Now, he can't understand why a bike computer in normal mode isn't up to the task. He is wondering why I can't calibrate it on a calibration course, measure the road course to where the computer just clicks over to 13.00 miles, and then measure the remainder with a steel tape. I'm trying to impress on him all of the idiosyncrasies that an electronic cycle computer has that may make it not reliable.

I just posted a question on the Electronic Measurement Forum asking what specs and/or qualities would a cycle computer need to have to be used to measure a road course directly in mi or km without having to revert to counts per mi or km and the calculations that go along with those factors?

Thanks,
Bob

Bob,

First, I would encourage you to practice a bit before doing the official measurement. With your Jones, note the start clicks. Ride a route through the neighborhood, doing some left-hand turns and right-hand turns. Follow a few curvy roads. Note your end count, and calculate the total counts. Ride the course again, preferably in reverse. See if your click-count is within .008% of the first ride. Do this a few times, until you are confident you are riding the shortest possible route (SPR), and that your route is repeatable. It is daunting to start measuring a long course, that being the first time you compare counts. If the counts on your first official course aren't close enough, you get to ride the course again, at least one more time.

Also, the only way to measure to USATF standards is to calibrate, and do clicks per mile. The reason is that most bike computers only show to the 1/100th of a mile, while we measure a 5k, for example to 3.10686 miles. Also, a half-marathon is 21.0975 km, which also is too precise for a cyclometer.

Good luck!

Thanks for all of the information, suggestions, and policy clarifications. My avocations have been cycling, computer spreadsheets, programmable pocket calculators, measuring various quantities, and gadgets. They can all come together in this task. Riding extra times to get it right while learning won't bother me as I generally ride 15-25 miles most every day anyway. I ran 5 and 10 K's and a few marathons in my younger days so am familiar with the Shortest Route Possible. What concerns me most is doing the SRP on a bike on residential streets - especially doing it in reverse. I can do it when traffic is pretty light but not non existent.

Thanks again,
Bob

Bob,

Sounds like you have the right type of personality - detail-oriented.

I offer a spreadsheet for everyone's use at my website, which will do most of the calculations needed. It is the entire Certification Application, and can be saved or printed as a PDF for submission.

SPR can be daunting, but also a nice challenge. Sometimes you have to wait for traffic to clear, then dart across the stretch of road. Makes life interesting! But, do it a few times, and it becomes second-nature.

Good luck!

Duane,

Got your spreadsheet. It looks great and will be fun to work with. Thanks for the advice.

Bob

Duane,

Excellent forms. I created my own in three macro-enabled Word docs. For the course measurement data form, John Sissala (MD Regional Certifier) worked with me to create a way to present the data clearly for review.

Bob, feel free to use these forms if you find them useful.

These forms are customized with my info, but anyone who has the link below can access them and modify them for his/her own use. To do this, click the "protect document" link when the .docm is open. Next, click "stop protection". Then, go to "Design Mode" (under "Developer" in Word 2007). Now, you will be able to enter your name where you want it on the form and remove mine. Be sure to exit "Design Mode" before saving. You must click "save" before clicking "start protection". You can skip entering a password if you like. Simply hit "enter" to protect with a blank password. You will be prompted to save again when you close the document.

This type of form will appeal more to the visually-oriented person than the engineering-oriented type. I use these forms to design the pages of the notebook I use when measuring. It them becomes a simple and fast transcription job when I get back to my desk after measuring. Now if I could just devise a way to make my maps as quickly...

These forms are available here: [URL= https://docs.google.com/leaf?i...en&authkey=CP3LxMwC]

Race Resources Certification Forms[/URL] https://docs.google.com/leaf?i...=en&authkey=CP3LxMwC

Lyman Jordan
www.raceresources.net

Sorry - I need to send a separate link for each document.

The previous link was the Certification Application. Here are the Measurement Data form and the Calibration Data form:

https://docs.google.com/viewer...=en&authkey=CLWTk_QE

https://docs.google.com/leaf?i...=en&authkey=CMLbz-0B

Enjoy.

Lyman Jordan

Lyman,

Duane pointed out to me that you don't have any intermediate points(i.e. miles/km splits). These are always good to have especially for a new measurer. Just having a start and finish could present problems.

I have a spreadsheet that does it all. Anyone interested please email me at xnjnowaz@gmail.com