Unread postby KirkB » Sun Feb 15, 2009 3:06 am
Golfdane, if you're going to be buying mostly Nordic poles (cheaper shipping), then I suggest you not worry about how the American poles are rated for weight/flex, and just use your own rig for figuring out the equivalent Nordic flex numbers.
In a nutshell, I think the American poles are all measured with a span starting at the butt plug, and measuring to a point 6 inches below the pole length. This would be consistent with the NFHS rules, which state that you cannot grip a pole's top 6 inches. I think the weight was 50 pounds, placed mid-span. However, since NFHS rules don't apply in Europe, and since your athletes will be more familiar with Nordic weights and flexes, you just need to convert each American pole you have to the Nordic system. And if this is NOT how American poles are measured, then it's immaterial anyway, since you only need to get the equivalent NORDIC flex #s.
I would start out by finding out how Nordic measures theirs. If you can't get that info from the mfr or any dealers, then just measure the Nordic poles that you have in your inventory. Start with the same span as the Americans, and see if the flex numbers match up. If they don't, see if moving the top point of the span up or down gives you an identical flex to the mfr. Once you match up a few poles, you'll know the span that they use. However, maybe they don't use 50 pounds, which could throw a monkey wrench into the works. Then you'll have to vary the weight AND the span. With 2 variables, it's not as easy to figure out.
Then, once the Nordic poles are all verified, your rig is calibrated and ready to use on your American pole inventory - using the same spans and mid-span weight.
I wouldn't worry about the imperial lengths of the American poles. Instead, record the flexes for the spans that your vaulters are likely to use on the poles. For example (and I'll use imperial measures here, since I'm hopeless with the metric system), if you have 14-0, 14-6, and 15-0 poles, your vaulters are likely to grip from 12-6 to 13-6 on the 14-0 footer, 13-0 to 14-0 on the 14-6 pole, and 13-6 to 14-6 on the 15-0 footer. So, in 15cm increments (the metric equivalent of approx 6 inch) - or whatever the normal increments are for the length of Nordic poles - record the flex at the 3 spans that a vaulter is most likely to grip that pole at.
By this process, you will have 3 flexes for each pole thru a range of 3 grips. So even if you have some gaps in your pole lengths, you should be able to compare apples to apples with one pole length to another. As long as the spans are identical, the flex deltas should be a fairly accurate indication of relative stiffnesses.
If you have lots of poles, and hardly any gaps between pole lengths (i.e. lots of poles at each weight in 6-inch pole length increments), then you can probably get by with recording only 2 flexes per pole. Having 3 flexes per pole just makes it easier when you have gaps in your pole lengths.
I suggest you assign a unique 2-digit number to each pole, starting from 01, 02, 03 ... Assign your American pole IDs (IDentifiers) first, then your Nordic poles. Every time you buy a new (presumably Nordic pole), use the next highest unused ID. The ID marked on the pole will then be not only unique, but over time, it will remind you of how new it is (relative to all your other poles).
If some of your vaulters own their own poles, I would assign 2-digit IDs to them too (but just keep track of who owns them). That way, they can also easily transition from personal poles to club poles by the Nordic flex number system that you've set up.
Hope this helps.
Kirk
Run. Plant. Jump. Stretch. Whip. Extend. Fly. Clear. There is no tuck! THERE IS NO DELAY!