Disc Talk, Pt. 1: Flight Plate, Bead, Tops, Bevel, & Injection Point

UDisc Staff avatar
Jan 28, 2019 • 5 min read

All hobbies and professions have their jargon. For example, as a former high school teacher, one author of this piece1 sometimes had to write IEPs for students who weren’t doing well in his inclusion classes (unless, of course, they had a 504).

The incomprehension you might have felt reading that last sentence is exactly the feeling many have when coming across disc jargon for the first time. So, we thought we’d take a little time to cover some terms that might come up when talking discs.

For our first article on the topic, we mostly stuck to terms that are used very frequently. However, we couldn’t resist throwing in a little bit of the tech behind disc-making at the end.

1. Flight Plate

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We’ve most often heard “flight plate” in the context of windy days. For example, “Oh man, once the flight plate got exposed to the wind, my putt got knocked down. It would’ve gone in any other day." 

The flight plate is simply the part of the disc that fills in the space between the rim. While it’s usually the bottom of the disc we think of when thinking of flight, both the top and bottom of the disc are parts of the flight plate.

2. All About Beads

If you’ve been around the sport long enough, you’ve doubtlessly heard someone talk about beads. Some disc golfers hate them, others love them, and many couldn’t care less. Still, it’s a term worth knowing for anyone pouring over disc descriptions.

Discs don’t get beads by showing their flight plates at Mardi Gras. They’re intentionally added to discs from the start. When a disc has a bead, you can find it jutting out from the bottom of the disc’s lip. The image below shows the difference in a beaded and beadless disc.

bead v beadless (1).jpg

In this 2013 interview with The SpinTV, Innova cofounder Dave Dunipace explained the purpose of beads is to “keep the disc stable for longer.” It doesn’t make the disc more stable, however. It just assures a straighter flight for a longer period of time.

3. Pop Top/Puddle Top

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These terms refer to whether the top of a disc’s flight plate tends to “pop” up with an apex at the center (pop top) or do just the opposite, with the lowest point of the flight plate’s top being the center (puddle top). Pop top discs are also commonly referred to as “dome-y.”

While many people seem to believe that pop tops usually have more glide due to the increased space for air on the underside of the flight plate, we’re not physics experts and can’t endorse this. And we’re not even going to touch whether these tops affect stability.

It’s also worth noting the term “flat top,” which refers to a disc that—you guessed it—has a flat flight plate.

4. Beveled Edge

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The beveled edge revolutionized disc golf in the way that legalization of the forward pass did to U.S. football or integration of the three-point line did to basketball.

The explanation of the beveled edge is relatively simple; it’s when the edge of a disc coming from the flight plate creates a wedge rather than going straight down (see picture above). The wedge allows a disc to cut through the air much more efficiently, making it both fly farther and have a more predictable flight pattern.

While it’s simple to say what it is, it’s really hard to emphasize the magnitude of its effect on disc golf enough. The aforementioned Dave Dunipace was the first to bring the beveled edge to discs, creating the first-ever disc golf disc—the Eagle—in 1983. Without it, courses would be shorter and, likely, the game would be less fun for many to play and watch.

For example, do you want to live in a world where shots like Nikko Locastro’s legendary, nearly 700-foot/213-meter bomb from the 2016 Disc Golf Pro Tour Championship on Hole 18 at the Fox Run course in Vermont isn't possible? We sure don’t, and we doubt all the people cheering in the video of it would either.

5. Injection Point, Parting Line, and Sprue

We’ll finish up with the nerdiest set of terms we’re going to go over.

Discs are made by a process called injection molding, where plastic pellets are heated until fluid, injected into a mold to set, cooled, and then released into the big, wide world. It’s not too hard to find the evidence of this process when you look at your discs.

Looking in the exact center of your disc, you’ll usually see the injection point. This is evidence of the device used to inject the liquid plastic into the mold. You can see what an injection point might look like in this short clip from a video by Engineer Guy on YouTube. It’s the opening connected to the long, skinny yellow part.

Like in the video, small points of plastic stay attached to discs as they come out of their molds. These plastic points are called sprues and are detached after a disc comes out of the mold. The spot left over after they're gone is still called a sprue, and they're pretty easy to find.

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The last trace of the injection molding process we’ll touch on is called a parting line. Again, Engineer Guy has our backs on explaining this one.

And here's one last picture to show you the parting lines on actual discs.

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1. This article was co-created by longtime Open player Tony Ferro and Release Point's editor, Alex Williamson.

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