In this article, we will review the Onix DuraFast 40 pickleball and compare it to the Franklin X-40 pickleball. In a previous article, “How Many Games will a Pickleball Last?”, we looked at the Franklin X-40 pickleball, as it appears to be the ball of choice among pickleball players in South Florida.
In recap, we tested the compressive stiffness of several Franklin X-40 balls after one, two and three hours of play. Each hour represented about four doubles games among aggressive 3.5 players (bangers). These tests found that the X-40 loses about 10% of its stiffness after each hour of play. After three hours of play (roughly twelve games), it was not possible to make reliable stiffness measurements because of soft spots that developed on the X-40 balls. The balls were subsequently “retired” to non-competitive recreational play and practice, where they were played for well over twelve more games before they eventually cracked.
In our series of pickleball reviews we will keep a running table of results and compare the reviewed balls to one another. We will assume that the balls meet the basic requirements as laid out by the USAPA regarding diameter, weight, and bounce, so there is no need to re-test for compliance to these standards.
Appearance
Neon green and yellow are the most popular color for outdoor pickleballs. As shown in Figure 1, the DuraFast 40 neon green has a darker green hue than the X-40 neon green. The DuraFast 40 also has a glossier finish compared to the X-40 matte finish, indicating that the DuraFast 40 may be smoother. The difference in surface smoothness is irrelevant since after two or three games both balls become highly scuffed.
Like many high-end pickleballs, both the DuraFast 40 and the X-40 are seamless; however, many purchasers will notice a slight seam (that we will call the equatorial seam) that separates the two symmetrical hemispheres . This should not be cause for alarm. Both the DuraFast 40 and X-40 are manufactured using a rotational molding process (i.e., roto-molding) where molten plastic is injected into a two-part mold that is rotated until the plastic solidifies. The ball is released from the mold by separating the two parts of the mold, and the seam is an artifact of the parting line between the two halves of the mold. Neither the Durafast 40 nor the X-40 are created by welding two hemispheres of a ball together, and both balls indeed consist of a single piece of plastic.
Holes
Both the X-40 and DuraFast 40 appear to have holes that are drilled in a non-uniform pattern (Figure 1). This seems to be a common complaint among purchasers of these balls. This should not be cause for concern because on closer inspection you will see that the hole pattern is in fact uniform. By drawing lines that connect the holes around the equatorial seam, we can see that there is a concentric pattern of three rows of holes per hemisphere on both the Franklin and DuraFast balls (Figure 2). This pattern is common to all outdoor 40 hole pickleballs:
- There are eight holes on each of the two staggered rows that straddle the equatorial seam, making for a total of sixteen holes.
- The next two rows of holes that are one row removed from the equatorial seam each contain a staggered pattern of eight holes, making for another sixteen holes.
- Farthest away from the equatorial seam there is a pattern of four holes on the top and bottom hemispheres, making for a total of eight holes.
- Adding up all of the holes within the six rows of holes yields a total of 40 holes (16+16+8=40).
On closer examination of the DuraFast 40 ball (Figure 2), we see that the holes have different diameters! On the first line of 8 holes adjacent to the equatorial seam, the holes have a diameter of 0.26”, but on the second line of eight holes, the holes have a diameter of 0.32”. On the other hand, every hole on the Franklin ball has a diameter of about 0.29”.
Onix (DuraFast) holds a patent on the use of different hole sizes in their pickleballs (USPTO US 8,357,062 B2). The fundamental claim of this patent is that the use of different hole sizes is effective in reducing damage to the ball during use. The holes near the equatorial seam are smaller, allowing more ball surface area adjacent to the equatorial seam, thereby reducing potential failure along the seam. (Note that this should not be a concern because the DuraFast 40 ball is roto-molded.) The holes on the next row farther from the equatorial seam are larger to increase air flow through the ball.
Calculating the total open area due to holes, we find that the DuraFast ball has an open area due to holes of 2.56 sq. in. On the other hand, the Franklin ball has an open area due to holes of 2.64 sq. in. Based on common knowledge* that balls with smaller holes will be less susceptible to wind and aerodynamic drag, the DuraFast ball might have a slight edge in aerodynamics when compared to the Franklin ball, and therefore might be a faster ball than the Franklin.
* Pickleball Science has not yet proven scientifically that that smaller holes are more aerodynamic than larger holes, nor have we determined the effects on aerodynamics of the different hole sizes on the DuraFast ball.
Stiffness and Durability
In a previous article (“Why Do New Pickleballs Have More Pop?”) we explained how the stiffness of the ball affects game play. Using the same test apparatus and methodology used in “How Many Games Will a Pickleball Last?”, we measured the stiffness of the DuraFast 40 ball when it was new and during incremental use after 6, 12, 24, and 32 games. We also performed visual inspections with a microscope and weighed the balls. These analyses and tests indicated the following:
- A new DuraFast 40 ball has a stiffness of about 130 lb/in, whereas the stiffness of a new Franklin X-40 is about 94 lb/in (Figure 3). The new DuraFast 40 is therefore almost 40% stiffer than a new Franklin X-40.
- The stiffness of the DuraFast 40 ball changed only 8% in 32 games, or about 0.25% per game. On the other hand, the Franklin X-40 lost 10% of its stiffness with every four games played, or about 2.5% per game, which is ten times that of the DuraFast 40. Readers should be aware that both the Durafast 40 and the X-40 were played very aggressively by 3.5 level “bangers”. You should expect the balls to last longer if you play a softer or slower game.
- After about 32 games, players complained that the DuraFast 40 was wobbling. On closer visual inspection under a microscope, it was found that the ball had developed cracks around some of the holes (Figure 4). These cracks affected the ball’s aerodynamics and caused it to wobble.
- Even when it cracked, the DuraFast 40 still had a stiffness of 120 lb/in, a decrease of only 8% in stiffness verses when the ball was new.
- The X-40 lasted about as long as the DuraFast 40 before it cracked (about 30 games), however, because the X-40 had become very soft, we could not reliably measure its stiffness and therefore stopped measuring stiffness after about 12 games. The data shown in dashed lines in Figure 3 are an estimate of the stiffness based on the data trend in the first 12 games.
- Both the DuraFast 40 and the X-40 had a weight of 0.95 oz when they were new. After about 30 games, the balls were re-weighed and it was found that the DuraFast 40 maintained a weight of 0.95 oz but the weight of the X-40 reduced to 0.92 oz. Excessive wear on the ball resulting in a reduced wall thickness may be one of the mechanisms by which softening of the X-40 occurs with incremental play.
Both the Franklin X-40 and the DuraFast 40 are high-quality pickleballs that have differences in stiffness and durability that may make them better suited for players of different skill level. Like paddles, a player’s choice of pickleball is a matter of personal preference. Important parameters that might be considered include how well the ball bounces against the court, how well the ball bounces against your paddle (reactivity), and the ball’s speed and aerodynamic flight as it travels through the air. Recognizing that there are no “right answers”, we are not recommending or endorsing one ball over the other in our overall assessment below, and readers should select the ball that best suits their abilities and style of play.
Assessment
As the name suggests, the DuraFast 40 ball is both durable and fast, and would be considered a high stiffness ball. Surprisingly, the ball maintained its stiffness even after more than 30 games when cracks developed. The stiffness of the ball contributes to its speed, so the DuraFast 40 would be considered a fast ball. This ball might be suited for intermediate to advanced players who want a faster game and can hit the ball hard with lots of spin and speed. These players should be capable of hitting the ball reliably at the paddle sweet spot and have good foot speed and mobility. Based on momentum exchange considerations (see “Paddle Weight and Momentum”), the DuraFast 40 would work best with power paddles.
Beginners may not benefit from the stiffer DuraFast 40 ball because ball speed is enhanced through the trampoline effect of the paddle. If the ball is not hit hard enough or consistently at the sweet spot, the paddle will not exhibit a trampoline effect, and additional energy and speed will not be imparted to the ball. Furthermore, the ball will feel “heavy” to beginners. As we discussed in our article, “Paddle Weight and Momentum”, the momentum of the ball must be overcome by a combination of force and contact time from the paddle. A stiffer ball will have a shorter contact time, thereby increasing the impulse force, requiring more arm strength from the player – thus the “heavy” feel. On the other hand, a softer ball may feel too “light” to a hard-hitting advanced player. The reason lies in the fact that the ball is not interacting with the paddle and enabling the trampoline effect (see our article, “Why Do New Pickleballs Have More Pop?“). A softer ball will therefore not come off the paddle crisper or with more velocity than a stiffer ball.
The Franklin X-40 should be a good “all around” ball for most recreational players. Its medium stiffness would make it a medium-speed ball, suitable for intermediate players with a 3.0 to 4.0 skill level, or players who desire a slower game. These situations may arise if players have limited mobility, or sore muscles, or if they are playing individuals with a wide range of skill sets, or if the players are just tired. The X-40 and DuraFast 40 will behave about the same for most serves, lightly hit balls, finesse shots, drop shots and dinks. The X-40 will feel slower than the DuraFast 40 only for harder-hit balls, like drives from the baseline, overhead smashes, and hard volleys near the net. Based on momentum exchange considerations (see “Paddle Weight and Momentum”), the Franklin X-40 would work best with control paddles.
The DuraFast 40 and Franklin X-40 are comparably priced on PickleballCentral.com*, with a dozen Durafast 40’s costing about $40 ($3.33/ball)and a dozen Franklin X-40’s costing about $36 ($3.00/ball). A more comprehensive review of several balls can be found in a subsequent post, “Pickleball Reviews“.
* Some of the embedded links in our website are affiliate links, meaning that at no cost to you, Pickleball Science will earn an affiliate commission if you click through the link and finalize a purchase. Purchase of merchandise through these affiliate links will help support the PickleballScience.org website so that we can continue to provide meaningful content to our readers.
