New Balance FuelCell SuperComp LD-X v3 review

After testing the New Balance FuelCell SuperComp LD-X v3, we recommend it for:

• Long-distance track athletes who prefer a softer ride than most elite spikes.
• Runners who enjoy a highly stiff and propulsive feel underfoot.
• Athletes looking for a track spike with a higher than usual drop.
• New Balance fans who want the familiar FuelCell experience for track workouts and competition.

The LD-X v3 offers impressive versatility, but athletes primarily focused on the 800m and 1500m may be better served by the New Balance FuelCell SuperComp MD-X v3, which is more specifically tuned for those events.

We also believe that some runners will prefer a firmer and more traditional spike feel. In that case, the ASICS Metaspeed LD 2 and Nike Dragonfly 2 stand out as excellent alternatives.

With 18.5 mm of foam under the heel, the New Balance FuelCell SuperComp LD-X v3 stays fully competitive with the top long-distance spikes on the market.

As you may already know, World Athletics reduced the maximum allowed stack height from 25 mm to 20 mm in 2024 for the Paris Olympics, and New Balance pushed the LD-X v3 close to that limit while remaining fully compliant.

The forefoot stack height of the FuelCell SuperComp LD-X v3 (New Balance really could simplify these names) measured 14.7 mm in our lab.

While it doesn't push the limits quite as aggressively as the heel, we still found it to be a very respectable amount of cushioning.

Unlike many track spikes that feature a zero or even negative drop, we found that the New Balance FuelCell SuperComp LD-X v3 delivers a more road-shoe-like geometry. Our measurements revealed a 3.8 mm drop, offering a less aggressive platform than many of its main rivals.

One feature that sets the LD-X v3 apart is its FuelCell foam. Based on our experience testing multiple FuelCell road shoes—like the New Balance FuelCell Rebel v5—we know this compound usually sits on the softer side of the spectrum. However, brands often firm up their foams when adapting them for track spikes.

That wasn't the case here. We believe New Balance wanted athletes to experience the same plush and energetic FuelCell sensation found in its road shoes, and our durometer backed that up with a soft 34.8 AC measurement.

There's a full-length carbon plate embedded in the shoe. It follows the proven formula used by many modern super spikes, with no foam positioned beneath the front section of the plate and maximizing responsiveness during toe-off.

We found the fit noticeably snug during our test runs, which is exactly what we'd expect from a performance-focused track spike.

To confirm our impressions, we created a gel replica of the toebox and measured a width of 88.6 mm, placing the LD-X v3 close to the current average for track spikes in our lab.

The second measurement came in at 69.3 mm, once again aligning closely with many competing spikes. As a result, we believe the LD-X v3 should feel familiar to runners transitioning from another modern track spike.

In our final toebox measurement, we recorded a height of just 23.5 mm, making the vertical space noticeably limited.

This low-profile design helps create a secure, race-ready fit, but runners should expect to feel the upper sitting closer to their toes than in most road shoes.

The carbon plate in the New Balance FuelCell SuperComp LD-X v3 is far from a marketing gimmick. In fact, it's one of the stiffest we've ever tested, playing a major role in driving the result all the way up to 19.5N in our flexibility test.

The New Balance FuelCell SuperComp LD-X v3 may have a lengthy name, but it certainly doesn't carry extra weight. Our scale showed just 5.3 oz (150g), a highly competitive result that aligns perfectly with what we'd expect from a premium long-distance super spike.

It may not redefine what's possible, but it still left us genuinely happy.

Breathability may not be a major concern in a sprint spike, but it becomes much more important in a model designed for long-distance events such as the 10K.

During our testing, we found that the LD-X v3 manages heat effectively, allowing air to move freely between the inside and outside of the shoe and helping keep the foot comfortable during longer efforts.

We also appreciated that ventilation isn't concentrated solely in the toebox. New Balance incorporated generous airflow along the sides of the shoe as well, while also enabling efficient water drainage for steeplechase races.

The upper itself impressed us with its premium feel and excellent construction.

Under our digital microscope, we observed a highly refined mesh with precisely engineered ventilation openings and outstanding build quality.

Padding is kept to an absolute minimum to reduce weight as much as possible. In our view, that's exactly what we'd expect from a performance-focused track spike built for racing at the highest level.

As expected from the combination of a stiff carbon plate and highly energetic FuelCell foam, the LD-X v3 delivered a high result in our torsional rigidity test. We recorded 12.3 Nm, confirming that rigidity was clearly a priority in its design.

On the other hand, the heel counter embraces a pure racing design with virtually no structure whatsoever.

In our manual assessment, it earned the lowest possible score of 1/5.

Another feature that separates the FuelCell SuperComp LD-X v3 from many elite competitors is its exceptionally wide forefoot platform.

At 102.9 mm, it offers an enormous landing area for a track spike, providing a reassuringly stable feel that we think will appeal to runners seeking extra support and confidence through the forefoot.

However, don't expect the same approach in the heel. Even a quick glance at the shoe reveals a classic track spike silhouette with an exceptionally narrow rearfoot, something we confirmed in the lab with a measurement of just 63.7 mm.

We were genuinely impressed by the heel padding's performance in our durability test, as it earned the highest score possible: a perfect 5/5.

The outsole of the FuelCell SuperComp LD-X v3 is remarkably minimal, measuring just 1.4 mm thick. This ultra-thin design highlights New Balance's clear focus on reducing weight while maximizing the amount of foam available underfoot.

The insole also embraces a minimalist design, measuring just 2.3 mm thick. Once again, this reflects New Balance's effort to maximize the amount of FuelCell foam underfoot while staying within the 20 mm stack height limit set by World Athletics.

The LD-X v3 uses thin laces that perform exceptionally well thanks to the reinforced punched eyelets, another detail that highlights the shoe's nice build quality. We also found that the tongue shape works particularly well for track racing, especially for athletes who prefer to race without socks.

We liked that the tongue is lined with a soft, comfortable material while remaining highly breathable. At 1.8 mm thick, it maintains a streamlined racing profile yet provides a touch more comfort than many competing spikes.

Another cool detail is the inclusion of a finger-loop heel tab, which not only makes the spike easier to put on but also cleverly conceals the upper stitching for a cleaner finish.

The FuelCell SuperComp LD-X v3 clearly targets the premium end of the market, as it's the long-distance spike trusted by New Balance's elite athletes. Even so, we think its pricing in the United States is surprisingly reasonable for a top-tier super spike.

Unfortunately, the same cannot be said for every region, as New Balance applies pricing conversions that make the shoe significantly more expensive in markets such as Europe.

We found that the LD-X v3 features a classic four-pin configuration, and New Balance includes a spike wrench in the box for easy replacement.