flexibility testing of discs (results and pics)

[slickwheels]

After reading some of the topics on disc flexibility I thought I should better understand the rule and see how it actually applies to discs I have.

Pdga says "(8) Flexibility - The disc is held on its edge in a vertical position perpendicular to a scale with a precision
of at least 2 oz. (56.7 g). The upper rim of the disc is then gradually pressed down within 5 seconds. The
flexibility rating is determined at one of two points, depending on how the disc reacts to applied pressure. For discs that buckle, the flexibility rating corresponds to the point when the maximum weight is
registered on the scale. For discs that do not buckle, the rating refers to the weight at the point when the
inside rim-to-rim distance is at 50 percent of the disc's diameter. The temperature of the disc is to be no
higher than 25 degrees Celsius (77 F) when the test is performed. The ratings of three samples are
determined, and the median score is used as the final rating. Discs that are unable to be bent to 50% of
their diameters fail the flexibility test. Manufacturers are required to send samples of the most rigid discs
they want considered for PDGA approval. "

I decided to set up a "MacGuyver" type testing facility and test a few discs.
The room temperature was 70 degrees. I used a standard household scale.
This is just for me to have an idea of what weight most common discs meet the pdga requirements.

1. dx leopard 18lbs

2. champ katana 18lbs

3. pro d nuke 23lbs

4. z tracker 16lbs

5. Gateway organic wizard 10lbs

All of the discs fell under the 27lb max limit. 27lbs is actually quite a lot of force once you actually feel it for yourself.

* sorry I have no stiff firebirds to test.

 

[Halcón]

Nice. But, the test is not very accurate with a bathroom scale.

 

[slickwheels]

If you put a 25lb weight on the scale, it reads 25lbs.
Not accurate down to the ounces but more than accurate enough for me to get a point of reference to better understand the rule and what people are talking about.

If you conduct the test yourself you will understand better, try it and post your results here.
This is more of a results thread than an argue about accuracy of whatever scale someone uses.

 

[jrawk]

hey slick.. thanks for this... question: did the nuke feel the stiffest of the bunch? or did you think something else would have scaled higher?

 

[slickwheels]

Of those above yes it did.

The stiffest disc I have is a weird stiff esp nuke. VVVV

esp nuke 24lbs

 

[TalbotTrojan]

It is really weird to see top quality discs bent like that. Then again I never thought to bend them like that. How do your results compare to the approved discs list?

 

[Huk Finn]

Where does a KC Pro Roc come in to play? Maybe even an 11x

 

[slickwheels]

The numbers the pdga approved list gives doesn't specify a plastic type so I wouldn't know what to compare. http://www.pdga.com/documents/pdga-approved-discs-pdf

According to the pdga numbers it says a nuke(no plastic specified) needs about 22lbs to fold, my numbers were 23lbs on pro d and 25lbs on esp.

Some of the pdga numbers are from 10 years ago so I don't know what plastic or plastics their numbers include or average.

 

[slickwheels]

Where does a KC Pro Roc come in to play? Maybe even an 11x

I have none of those to test, sorry.

x nuke 19lbs

pro d buzz 18lbs

These were just some randoms I had laying around. The z, champ and esp plastics all flattened back out on their own... the dx and pro d needed some tuning to be flat again. lol

 

[Carnavas]

:thmbup: This is pretty cool to see. Keep 'em coming!

 

[jchoate7]

That poor plastic. I would love to see what my discs are at but I'm scared they would stay a little bent.

 

[Carnavas]

I just did it with a champ sidewinder, it popped back just fine. As long as you don't hold it bent for an extended period of time, it'll be fine. (dx and its equivalents may or may not follow this trend)

 

[jchoate7]

I really dont want to know that bad at the risk of ruining a disc's flight characteristic though. I mostly throw Lat64 Gold Line anyways not that stiff at all really.

 

[Johnhilley44]

i imagine a kcp roc would snap before you bent it like that

 

[cjskier]

i imagine a kcp roc would snap before you bent it like that

Nope, just tried it, with a brand new one, room temp 65. It didn't flatten back out easily though.

 

[worldwide]

not all of those discs look bent to 50%

 

[slickwheels]

not all of those discs look bent to 50%

They are 50%. Bend a disc and you will see most get easier to bend once you pass 25-30%.

I encourage all who read this to conduct your own tests if you have any doubt to the legitimacy of my test.

I don't think people know just how much force 27lbs is.
As a reference if someone put 27lbs of pressure on your head you would be extremly uncomfortable

 

[Halcón]

I encourage all who read this to conduct your own tests if you have any doubt to the legitimacy of my test.

Your test may not be (or maybe it is) as accurate as the PDGA's. It does, however, give us a good idea of the flexibility of certain plastics.

It just kind of makes me cringe to see that plastic bent so much. Have you thrown the discs to see if their flight was altered at all? I'm curious if bending them that far would "tune" them or not.

 

[mattdabbs]

11x KC Aviar would be interesting to see. Some of those are brick hard and old. I bet they would bust right in half. But then you would be out $30.

 

[sugarnot]

My problem with all of this is the whiners at tourneys that are going to try to use this to get ahead. The problem seems to be that the PDGA isnt requiring this of every disc that comes thru to them so there are discs that arent mentioned. Then you are going to have a guy at a tourney who thinks someone elses disc is too stiff and whines to the TD and the TD not doing what is right, which is saying he isnt equiped to do such a test on behalf of the PDGA, BUT instead trys to do it and ruins someones favorite disc. It should be as simple as the PDGA approved discs list, if its on there you can use it, if it isnt you cant no matter how that disc actually came out of the factory. We all know that discs come from the manufacturers with variances but that isnt our place to police. If the PDGA wants to step in on that, let them but the only way I can foresee a result of that would be to have mandated quality standards....AND that I dont see happening. Fact of the matter is the PDGA, bless them for what they do have all sorts of rules/issues that they gotta work out, but I guess thats part of being such a "young" mainstream sport vs the casual unregulated one that it all started as.

sorry for my rant, but ive seen so much about this topic lately and i find it rediculous that it all requires so much thought.