How does a disc's weight affect its stability? I recently bought a Z-Buzzz and I like it, but I seem to be having trouble keeping in on a straight line. It's 178 grams, which is heavier than I normally buy discs in (only one the store had left). I've noticed that if I want to make it fly straight I have to really throw it hard with a lot of snap. Even then it only stays straight through 3/4 of its flight. And the courses I play are all fairly short, so there arent many holes where I can throw it hard without parking the disc past the basket. So far I really like the disc, so I'm wondering, if I drop down in weight to something like 164-166 will it be less overstable?

Also, I read that the color of certain discs (Wildcat, IIRC) affect its stability. Does this hold true for the Buzz? (i.e. blue most undertable, red most overstable)

In general, the lighter the disc, the more understable it will be.
I know firsthand, for example, that I can turn a 150g Valkyrie over easily, but cannot turn a 170g Valkyrie over (yet). Same with my Beasts.
The exceptions would be that some different weights of the same discs seem to come out of the mold shaped slightly differently. Orcs are one example of this. It seems that some of them are a bit domier than others and hence less overstable even though they are heavier.

how much weight affects the disc's stability often varies by molds. sharper nosed drivers with thin flight plates will generally have similar amounts of mass on the flight plate in heavy and light weights while having much less mass on the rim in lighter weights resulting in decreased gyroscopics and less overstability.

however, i have a 119g demon that is still very overstable (although it is easier to torque over) when thrown correctly.

also contributing to overstability, the inherent characteristics of the z plastic will make it finish earlier and with a little more fade. i might recommend trying to break that one in before you ditch it for a lighter one as i think the lighter one will probably have similar late flight characteristics when new but be slightly easier to turn over. whacking it into a tree over and over or throwing it hard into some firm packed dirt should help accelerate the process.

as for color coding, from chatting with Keith M, the main determinant is the run, but comparing colors within that run will usually yield some differences but it's not something that can be standardized across all discs/runs.

as for dome height, with most discs a higher dome = less overstable, however, with a lot of the newer discs this is not the case. with discs like the beast, champion orc, kc roc, and crush, the higher the dome, the more overstable. haven't been able to get to the bottom of this, but my theory is that on some discs when the flight plate domes up more and pulls the wing slightly upwards making it fly more overstable...

overall though, i prefer how discs fly broken in, as they are broken in for the majority of their lifespans and only new for a short time. the buzz will go farther in heavier weights than lighter weights and once it gets a few good tree whacks it should ease up the fade a bit.

Blake:

Seems to me the opposite is true??? My domier discs all seem to be more understable than the flatter ones.
Cheetahs and Leopards for me are domier and turn over more easily than Beasts and Valkyries and my one Orc, for example.
The depth of the rim under the disc must also be a factor. The Valks and Beasts have less of a curve (kerf in woodworking) than the Cheetahs and Leopards.
:confused:

P.S.
This is worse than the blue Orc mystery! /msgboard/images/graemlins/ooo.gif :D

Blarg:

i was comparing dome height within specific models. i.e. a domey champ orc will be more overstable than a flat champ orc whereas a domey predator will generally be less overstable than a flat predator.

Blake_T:
Now I'm really confused. I thought I had most of the physics figured out.
My 158g Orc is totally flat, and very overstable.

Maybe my throwing just sucks?
:(

there's a lot of thigns w/ disc shape that do not allow for "general rules" to apply. the wing shape and mass proportion are probably the most important factors in determining disc stability in drivers.

as for your experiences with the orc, they are extremely speed and nose angle sensitive. i find them a little more overstable than suits my tastes, but i know others who find them somewhat unpredictably flippy, and yet others that find them just right. there was a run of domey clearish white orcs that were very highly sought after by a lot of the pros because they were more overstable than the flatter ones.

I guess I'm confused because I've never seen a 'more domey' disc that is more overstable than a flatter one.
I also thought (still do) that wider rimmed discs, in general, were more overstable than narrow rimmed discs. Then I read that people find the 'Flash' understable. My Flash has the widest rim of any disc I've ever thrown, and for me, it is overstable. It's not broken in yet, though. :p

Re: Disc Weight and Stability -

My theory is that the lighter discs can seem less overstable simply because they are easier to get more snap or spin on. Also, it is easier to hold on to them longer into the hit/rip or whatever. The end result is that they are easier to turn over. It takes more over-all power to turn over a heavier disc.

From a physics point of view - If the shape of the disc is exactly the same (which is probably not true), and disregarding wind. If thown on the same plane, same spin, same speed, the flight of exactly the shape discs of different weight will have very little difference (at the speeds people throw them).

That being said, I agree that lighter discs seem less overstable. /msgboard/images/graemlins/smirk.gif

Blarg:

this sounds like an issue with nose angle (which often becomes troublesome for players as rim width increases). a wildcat is much wider than a banshee, but a banshee is definitely more overstable. however, a wildcat will be quite overstable when thrown nose up (as are most discs).

wider rimmed discs do have more gyroscopics since there will be a higher mass proportion on the outter edge of the disc and also often be faster (especially with a low profile) both of which will contribute to stability. however, there are more important factors in determining a disc's stability given a nose down trajectory.

as for color coding, from chatting with Keith M, the main determinant is the run, but comparing colors within that run will usually yield some differences but it's not something that can be standardized across all discs/runs.


I have heard second hand that when Discraft packs discs for shipping, it packs them in ROY G BIV order, and that that has as much to do with differences in stability and dominess between colors as any other factor, i.e., the weight of the discs flattens the discs on the bottom.

Don't know whether or not that's true, but it does seem to make sense.

Blake_T:

I think you are right. I'm just beginning to learn to really 'snap' a throw with the nose down and I'm certainly not what anybody'd call 'powerful.' :( Yet. /msgboard/images/graemlins/smirk.gif
Any driver over 165g is overstable for me at this point.
Never thrown a banshee or wildcat. I have many discs but I mostly use Valkyries, & Beasts, in all sorts of weights and plastics and dx Cheetahs and Leopards and 1 candy Orc.

I can flip the 150's pretty much at will, especially after they get beat up. This is why I always advise beginners to try lighter discs, as I learned a lot more a lot faster when I went down into the 150's. They also flew farther for me, almost immediately.

Blarg you would like a wildcat very fast disc with a slight right turn, awesome disc for someone who doesnt really throw far, thats is one fo the discs i started with, and infortuanlty i lost it and never did replace it i just bought more overstable discs and learned to throw them.

St_T_DiscGolfer:

Maybe I'll get a Wildcat some day and give it a try. I've stayed
away from Discraft discs as they were all too heavy for me. I don't think Discraft makes anything under 165g. I have one Discraft disc that has a '0' stability rating and is supposed to be understable. When I threw it flat, it went hard left every time.
Of course, it's over 170g. It says 'understable' right on the disc. I can't tell what disc it is as I've used it as a test disc for various disc-dying attempts and can no longer read the name. Can still see the '0' stability rating, though. It has an encircled 'Z' on it that I can still see, which narrows it down to what, one of ten discs named with a 'Z?' I can't keep track of Discraft discs as they are (IMHO) named stupidly. Xtreme, X2, XL, XS, Xtra, Xpress, X elite Z (???), etc.,etc., Xcetera. Retarded. :mad:
To be fair, I haven't tried it in a long time, as I found it useless.
Nothing I've thrown regularly in the past 6 months weighs more than 160g and most of my 'go to' drivers are around 150g.
:)

Blarg:

again, this sounds like an issue with nose angles. some discs have the characteristic that they can be thrown slightly nose up and "powered" nose down (in the turn) through speed/snap. most discraft discs do not respond well to this type of throw and must be committed nose down from the start, especially in z plastic.

Blake_T:
I think you make yet another good point. My biggest problem on long drives has been getting the nose down. That's why lately, I've been trying the 'lock the door' sort of wrist roll, with rather unpredictable results. Sometimes I have great results
(e.g. longest drive ever), but there must be a better way to get the nose down?
:p

for the sake of the tendons in your elbow i'd go away from the wrist roll if possible. have a few buddies coming off of injuries from that type of a thing.

as for tips on nose down, make sure that your shoulder opens on the same plane as you want the disc to come through on so as not to skew the nose upon release. the big one is the trajectory. i have an article describing this on my website.

for a hyzer-flip/flatten it's easier to get the nose down by launching the disc slightly left of center (center being the line with your right shoulder pointed at the target). similarly, for an anhyzer, you would pull it slightly to the right of center.

How the weights effect high speed drivers.
Here is alittle piece I wrote on the subject that may help answer some questions.
I am not an aerodynamicist, but I did stay at a holiday inn last week.

2 main factors effect a discs over stability when they begin to loose revolutions and velocity.
Assuming you threw the disc with proper technique, trajectory and angle in relation to YOUR revolutions and velocity ( hard enough to get on a flat flying plane for a long time enough to get forward penetration)
1) The main one; is deflection angles of the wing.
No matter what weight the disc is if there is more angle( concave radius) on the wing than the dome on the flight plate( anything above the parting line) it will begin to fade left as soon as the velocity begins to decrease.
example a Sabre has less or close to equal angle on the wing than on the dome which is why it is one of the best Gliding and landing discs on the market.
The speed Demon has a very long and fairly concaved wing which is a lot more angle( resistance) than the flatness of the top.( that�s why they cut back so hard even before declaration!)
2) The 2nd factor is gyroscopic weight distribution or ration of weight between flight plate and rim.
In the 185g Spirit I flew dead straight right out of the hopper, a lot of plastic got pushed into the flight plate making the ration of weight from rim to flight plate lean more towards the flight plate than in the 175 gram ones we ran after we got the profile of injection lined out.
The 175 and 185 were made from the same weighted batch of plastic, just pushed around differently by Temperature, Pressure and Speed!
Being that the Speed Demons and Spirits have the greatest difference of ratio between flight plate and rim( in a 175 gram Spirit or SD the ration would be rim= 120 and flight plate 55) This along with the ow overall height and sharpness on the nose is why our disc is the fastest on the market. Besides the Epic our 2 High Speed Drivers have the MOST gyroscopic weight distribution which allows it to SPIN FASTER AND LONGER.
Check out any competitive YO-YO or ask someone who competes about revolutionary designs in the past few years!
Just like the angles of wing deflection ,the close in balance the rim to flight plate ration is, the straighter the disc will fly on deceleration. Back to the reason why the Sabre flies so straight, the ration between rim to flight plate in a 175 gram Sabre is about 95=rim to 80= flight plate.

Blake, you rock! I just found your "Understanding Nose Angles and Trajectories" article:
http://www.discgolfreview.com/resources/articles/angles.shtml
and really look forward to reading it as the most difficult part of transitioning from years of Ultimate to disc golf for me seems to be not throwing nose up.

I was just curious about the flatter vs. domier discussion as I thought domier led to less stability. For example the lighter Orcs I have seem as stable as the domier max weight ones I regularly throw. Also, weren't the flat top CE Valkyries markedly more overstable than were there domier counterparts?