Why Your Disc Isn't Like My Disc - Volume 1: Parting Line Height

February 5, 2019

by Zachery Jansen

At MINT Discs, one of our cornerstones will always be the Serial # on our stock discs. This Serial # helps us all categorize and reference your favorite and least favorite run's of each disc..

We took that concept further in the early days of MINT by releasing color flight charts per run to help add that extra layer of definition. This color flight chart worked because we had a limited sample size of color's and only one disc.

Now to be honest - the actual color itself has nothing to do with flight. Disc golf companies don't add blue to affect a disc's stability. It's like cooking, if you change a major ingredient or method in the recipe then your final product can be affected. So this makes every run unique, sometimes down to the exact color, as adjustments are made for each changing variable.

As MINT grows beyond just the Alpha, it admittedly will be a tall task to keep up with the color flight charts but that doesn't mean we plan to stop providing what information we can. In the past we would take 1-2 months to really test out each color for the chart, but since the Alpha has become so popular, we need to provide that data when we release a new run. Not 1-2 months down the line when it is already sold out.

So how do we do that without throwing every color/weight combination? We measure what we consider the 3 most important factors - Weight, Dome, and Parting Line Height.

Weight and Dome are the obvious ones to most people, because you can tangibly feel the difference. So then, what exactly is Parting Line Height(PLH)? This term PLH has been used in the collector market for years to help measure stability.

Lets first take a look at this mock disc profile to help you visually understand:

The Parting Line is the point on the nose(on the wing) of the disc where excess plastic(called flashing) leaks out of the mold during production. Most of this excess is eventually trimmed away so that it isn't uncomfortable to hold the disc.

If you haven't already stopped reading & grabbed a few discs, then you should stop after reading this run on sentence and go grab 2-3 of your favorite Alphas, ideally from different run's, plastics and weights.

Got your favorite Alphas? Ok, now set them on a flat surface and try to find the parting line on each disc. Line them up to side to side to see how they compare. Based on how high or low that line sits we can then start to paint a picture of a discs true stability.

Why does this parting line move up or down? Why can't MINT just get it right every time? Well the concise answer goes back to our cooking recipe - if you change an ingredient or method, the result can be different. That difference is what we want to embrace at MINT. We know some run's might just fly completely different than another run and we start to measure it by looking at the PLH.

Let's next take a look at the variations that exist across some of the popular Alphas from 1st Run's to 4th - all categorized by Serial # and Color.

The dotted line representing PLH is an estimated "Goldilocks zone". This line is the 0 turn & 2 fade that produces that straight initial flight, with a reliable late fade. The top of each color block represents the PLH of each color. As it goes up or down so does the wing of the disc, leading to a change in expected stability.

Now the first thing to make clear - these PLH measurements are 100% a generalization and based on the discs in our bags and collections. It might not describe your exact disc, and we honestly hope it doesn't. The goal here is to give you tools to understand why stability might change from run to run or plastic to plastic.

We used 2 methods too compare:

Tape Measure or Ruler - place disc(s) on flat surface and measure from surface to parting line.
The Line-Up aka "Eyeball that sucker" - All kidding aside we just lined up the discs next to each other and organized them based on how the PLH sat in order from lowest to highest on each disc.

Important Notes: When comparing parting line, stick to one disc model. If you compare multiple models to each other, the results will obviously be different. Also if your parting line isn't visible, it might be worth measuring to something else like the bottom or top line of the nose on your disc.

If you know your Alphas - you should quickly be able to pick up on some well known details. Two of the most overstable runs to date have been the 3rd Run Sublime and 1st Run Nocturnal Glow. This is mainly because the parting line is so high up. You'll then see at the other end of the spectrum is one of the least stable(and most popular) Alphas - the 2nd Run Royal Blue Sublime. In between are popular colors from other run's, as well as a few choices from the recent runs of Apex, Eternal and Sublime.

Which brings us to the real reason anyone is probably reading this - how does this apply to the Apex 3rd Run, Eternal 4th Run and Sublime 4th run that was just released? Well we'll wrap up the blog with all of our findings on those run's below.

We encourage you to measure your own discs and see how they all line up. Most importantly make sure to throw your discs for the ultimate test of stability.

All the following colors were the most common shades/weights we could find, and may not represent your exact disc. We made a vast array of colors for y'all in these 3 run's, so we knew it wouldn't be possible to get every color recorded.