measuring xc courses?

wilfredo wrote:

"then" is no the same word as "than"

"insure" is not the same word as "ensure"

And "no" is not the same word as "not".

shit

The JR Counter/bike is the most accurate, practical device available to measure road courses (You can achieve greater accuracy using dozens of people, shutting down the roads and steel taping as they do with some races in Asia!)

But, in my opinion neither the JRCounter/bike method or surveyor's wheel is accurate for measuring non paved surfaces such as a cross country course for all the reasons stated in the previous 12 pages.

Surveyor Steve wrote:

The Jones-Reigel unit is just a typical gear driven devise from what I have seen.

You must be the gandy guy.

What does "from what I have seen" mean, either you have used one or you haven't.

https://secure.wikimedia.org/wikipedia/en/wiki/Jones_Counter

Check out this link and hopefully you will SEE what I see.

https://secure.wikimedia.org/wikipedia/en/wiki/Jones_Counter

I don't see anything when I click on that link. So the Jones Counter is not real?

wilfredo wrote:

"then" is no the same word as "than"

"insure" is not the same word as "ensure"

Who do I send the ticket too?

This is the type of jones counter that I have.

http://jonescounter.com/resources/_wsb_473x213_Original+Jones.jpg

Here is an interesting history of the jones counter, originally made (in 1971) from a veeder counter produced in 1896.

http://jonescounter.com/2.html

J.R. wrote:

This is the type of jones counter that I have.

http://jonescounter.com/resources/_wsb_473x213_Original+Jones.jpg

Here is an interesting history of the jones counter, originally made (in 1971) from a veeder counter produced in 1896.

http://jonescounter.com/2.html

Yep - same unit as what I tried to post the link of.

I had one of those sent to me from a certified measurer in Illinois years ago and it sounded like a meet grinder on my bike. I was told I was riding too fast! I was not impressed, maybe the new version is better.

Because of this thread I feel like I should order one and toy around with it. Unfortunately, I'm running out of time this fall and the snow will soon be here. I may take it on as a spring project.

I've had mine since the mid 1970's and it's in great working order, very smooth and quiet. I might have greased or oiled it once, to help it run more smoothly.

I've not tried any of the newer versions. That 260/11 is confusing, as that would be 23.63 counts per revolution of a wheel.

My confidence is only with the type of jones counter that I have.

wilfredo wrote:

shit

I apologize for doing this, but someone was going to (however there is a difference between a typo and some other mistakes. That said, those words are often mis-spelled because people do not 'hear' them right and they are a little tricky. I myself have both problems, typos and spelling error from not hearing something correctly; I get assisted by programs that flag mis-spellings but not the ones that are valid words.

I may as well weigh in on the Gandy Counter and Jones Counter Model J-R

1) The Gandy web site does provide some useful information: It's a steel wheel with a gear-driven counter that reads in feet. Two issues come to mind:

(a) The diameter of a steel wheel will vary with temperature (that is why steel tapes show the temperature at which they are accurate, and why you need to use a temperature correction factor when measuring with a steel tape at another temperature).

(b) The Gandy Wheel reads in "feet." If you push the wheel for a distance, then look at the reading, you get a number, but this is not real feet (i.e., 30.48 cm); it is simply a digital number. Among other factors, how close to an actual foot the digital number is depends on the temperature of the wheel compared with that at which it was calibrated, and how much "wobble" there was while you pushed the wheel.

These could be overcome if the Gandy Wheel is simply used like a J-R counter: calibrating it by pushing it for a carefully measured distance (e.g., a distance measured twice with a temperature calibrated, stretched steel tape)on the same surface to be measured, and recording how many units the digital readout indicates for the known distance [ignore that the manufacturer calls them "feet"; let's call them "clicks"]. Repeat three more times to estimate precision. Then, measure your course (which should be the same surface as the calibration surface) at least twice, and ideally 3 or more times. Then do a post-measurement calibration checks of how many clicks per the known calibration distance used earlier. Then, use simple algebra - how many "clicks" for the known distance and how many clicks for the route of unknown distance. This would account for wobble and temperature, but would not address possible variations in surface characteristics along the route.

(2) The J-R counter is simply a gear-driven digital counter that can be attached to a bicycle wheel. It does not matter how may clicks it registers per revolution of the wheel (but the more the better). What matters is the number of clicks for a known distance compared with the number of clicks for an unknown distance on the same type of surface.

I attached a J-R counter to a home-made "measuring wheel" [mountain bike wheel, front fork, stem, handlbar]. When I walked a 1000' USATF calibration course [CA10054RS], I got 5315, 5316, 5315, and 5314 clicks. So, at that time my wheel measures 5315 clicks/1000'. I don't care how many revolutions of the wheel it showed, just the number of clicks. The numbers showed that my walking (on pavement) was pretty consistent, with plus or minus about 3.5 inches over 1000', or about 3 parts/10,000. It does not matter that I may have wobbled the wheel as I measured, since any wobble is consistent, and could be expected to be just as consistent while measuring a course (on a paved surface like the certified calibration course) that same day.

BTW, on his Jonescounter.com web site, Peter Riegel indicates that you should make sure your counter rotates smoothly before using it. If it grinds, make sure there is adequate clearance, and oil where there is metal-on-metal contact if necessary.

Interesting Points. I also went to the Gandy Web site and see that they have a model, the 1.5m, that does measure in meters.

I also find it interesting that a steel wheel could grow in size in warmer weather. I'm sure it does, but does it really expand and contract enough to be measurable? I see other companies use composite wheels - any expansion figures on those?

David Katz wrote:

This thread is sounding like the movie Groundhog Day!

Why have you not answered the requested questions?

I'm also curious how one measures with a steel tape. Is there a web site that would be beneficial?

The USATF Course Certification web site has a link to the course certification manual.

http://www.usatf.org/events/courses/certification/manual/

It describes how to use a steel tape. Steel tapes used for outdoor measurement are marked with the temperature for which they are calibrated (typically 20 degrees C, which is about 68 degrees F), and the force with which you should "stretch" them before measurement (typically in the range of 50 N, which is about 11 lb - you can use a fish scale with a hook to stretch the tape before recording the distance). Steel has a coefficient of thermal expansion. You can see the discussion in the USATF manual, or do a web search on the term for more information. It's not a big difference, but enough so that course certifiers need to take it into account when using a steel tape to set up a calibration course (the tape expands about 4 inches per mile for every 10 degrees rise in F temperature - this does not seem like much, but as a point of interest it was a big deal in the development of continuous steel rail for railroads).

I'll leave the calculation of how much the Gandy Wheel is affected by a change in temperature as a problem for some engineering or physics students reading this blog to ponder.

If'n your gonna gramma police don't be makin no mis-steaksPutting aside a potential run-on, missing commas, the debate about ending sentences with "to", and unmatched parentheses, just how do you spell "misspell"?Perhaps all y'all just might want read this poem, written by Jerry Zars in 1992, on the merits of using a spell checker.http://www.bios.niu.edu/zar/poem.pdf

26mi235 wrote:

I apologize for doing this, but someone was going to (however there is a difference between a typo and some other mistakes. That said, those words are often mis-spelled because people do not 'hear' them right and they are a little tricky. I myself have both problems, typos and spelling error from not hearing something correctly; I get assisted by programs that flag mis-spellings but not the ones that are valid words.

Maybe it was a 'Najavo' mistake (they put small flaws in to weavings because only the gods could be perfect). Using the spell checker is better than not doing so.

David Katz wrote:

The JR Counter/bike is the most accurate, practical device available to measure road courses (You can achieve greater accuracy using dozens of people, shutting down the roads and steel taping as they do with some races in Asia!)

But, in my opinion neither the JRCounter/bike method or surveyor's wheel is accurate for measuring non paved surfaces such as a cross country course for all the reasons stated in the previous 12 pages.

I have read all posts in this thread and have found little support for why a surveyor's wheel is not accurate for mesuring cross country courses. I find it absolutely crazy that a steel tape would be even considered to try and measure a cross country course. Even on a road course, I question the process of measuring curves while maintaining proper tension on a steel tape. Is there anyone who has video of proper technique with a steel tape, especially what to do on corners and when one comes across depressions on the running surface of a cross country course.