New Balance FuelCell SuperComp Trainer v3 review

Our lab tests and extensive road trials have shown that the SC Trainer v3 is:

• Ideal for enthusiasts of the SC Elite v4 looking for a durable, more affordable training shoe that retains a familiar feel.
• Perfect for marathoners in search of a carbon-plated, plush shoe suitable for fast workouts and long runs—at a price point well below many high-end supertrainers.
• A great option for runners who were less impressed with earlier versions, as we've noted significant improvements making this the best iteration yet.

Despite upgrades from version 1 & 2 and an all-new PEBA-blend midsole, we found that the SC Trainer v3 falls short in energy return compared to other supertrainers. For those concerned about this aspect, we recommend considering the Saucony Endorphin Speed 4 or the ASICS Superblast 2, as both offer superior bounce with every stride.

Additionally, our lab tests showed that the SC Trainer v4's weight is a bit higher than ideal, which could deter some runners from opting for this model. If you're looking for a lighter option that still includes the benefits of a carbon plate, the ASICS Magic Speed 4 could be a more suitable supertrainer that also offers more stack height.

It’s interesting to observe that while most running shoes are increasing in height each year, the SC Trainer is actually getting lower with each version. The original model started with a heel height of 40.2 mm, then New Balance reduced it to 39.3 mm, and now it's at 36.8 mm.

Whether this reduction is beneficial depends on your preferences. We've noted that those who prioritise stability will appreciate this change, as the lower stack height balances the super-soft midsole, resulting in a more stable ride. However, enthusiasts of ultra-cushioned, maximalist shoes might find it lacking and could consider the Hoka Skyflow for a more protective ride at a similar price.

The forefoot features a substantial 29.5 mm thickness, offering a generous stack height that is ideal for both midfoot and forefoot strikers.

This design makes the shoe exceptionally well-suited for handling the demands of long runs, particularly for marathoners. In fact, we believe this is one of the primary applications for this shoe.

After calculating from the previous two measurements, we determined a 7.3 mm drop. This makes the shoe suitable for all types of footstrikes, but we feel it's especially perfect for midfoot strikers.

This measurement also aligns closely with the official 6 mm drop reported by New Balance, so we have no issues there!

The most significant update in the SC Trainer v3 is the new formulation of FuelCell foam. While you might recall that version 2 also featured FuelCell, this iteration is way different.

As we've discussed in our guide on running shoe foams, brands often use the same name for different materials, and this time, it's not the old FuelCell from a year or two ago but a new blend of 20% PEBA and 80% EVA.

Contrary to the top-tier Elite v4, which boasts a 100% PEBA midsole—our preferred choice for performance—New Balance opted for more durability and affordability. They've used the previously mentioned blend of PEBA and EVA.

This mix is decent and maintains the characteristic pillowy-soft feel synonymous with all FuelCell foams, likely the reason behind keeping the name. And while it may not be the bounciest out there, with a softness rating of 8.8 HA on our durometer, we can confirm that it certainly feels like running on clouds.

After an initial setback with the SC Trainer v3, we shifted our focus to testing the heel padding—an area that typically raises concerns regarding wear and tear.

Fortunately, the results here were dramatically better. We were thrilled to award a 4/5 after evaluating the resilience shown against our testing tools. This marked a significant improvement that positively impacted our overall assessment of the shoe's durability.

We conducted a cold-weather test on the SC Trainer v3 by placing it in the freezer for 20 minutes before assessing its softness with a Shore A durometer. Interestingly, we found that it got 27.1% firmer. However, given the original buttery-soft nature of the FuelCell foam, it still registered an incredibly soft 11.1 HA!

We measured the insole at a thin 2.9 mm—absolutely ideal for this type of high-performance trainer.

The SC Trainer v3 features a full-length Energy Arc plate, which is more than just a fancy name. Rather than using a flat plate against a full slab of foam, New Balance has paired an open channel in the midsole with a concave plate to, supposedly, enhance energy return.

Does it work? While we can't definitively say, we're hopeful, as the trade-off is that the shoe tends to catch pebbles if you run on gravel roads. What we can confirm though is that despite being made from carbon fibre, it feels less aggressive and stiff compared to most racers. And that makes sense for a uptempo training shoe.

Both previous versions of the SC Trainer offered a rockered ride despite significant changes in design and stack height, and version 3 continues this trend with minor changes.

It features a pronounced rocker in the forefoot and a heel bevel too, essential due to its stack height and carbon plate, though it is not as dramatically curved as the Hoka Cielo X1 or the SC Trainer v2.

Now, let's discuss the fit. From our initial trial of the SC Trainer v3, we immediately noticed it was the most spacious of the three editions—a fact confirmed by our measurement of 99.8 mm across the widest part of the toebox.

This model eliminates the unwanted pressure found in v1 and is indeed a tiny bit wider than v2. We found this extra space essential, making it an excellent choice for long-distance workouts.

Our second measurement, taken in the big toe area, also indicated a decently roomy fit, although the vertical space is somewhat limited here. This may be a concern for runners who experience pressure on their toes or commonly suffer from black toenails.

However, as a performance trainer, this shoe should also offer a snug fit. We've noted that it's challenging to accommodate every preference, but this design definitely aims to balance comfort and performance.

Despite its high stack height and plush foam, this shoe surprisingly maintains stability. We found that New Balance has impressively integrated numerous non-intrusive guidance elements to achieve this.

One key feature is the large central groove extending from the heel to the midfoot, which we discussed in the plate section. Additionally, the broad sole flare and raised midsole sidewalls, coupled with the carbon plate, not only stiffen the ride but also significantly enhance support.

Equipped with a carbon plate, the results of this test were expected to be exceptionally high—and that's exactly what we achieved in the lab: a score of 5 out of 5, indicating an incredibly stiff build.

The heel counter truly embodies the "Trainer" aspect of the shoe, scoring a 3 out of 5, which aligns more with a standard daily trainer than any racing shoe. We celebrate this design choice because it contributes a much-needed bit of stability.

As we noted in our initial analysis of stability, the SC Trainer v3 features a significant sole flare, where the midsole expands laterally to stabilise and centre the foot within the shoe.

After testing this on the run and returning to the lab, we measured a substantial 117.7 mm in the forefoot. This measurement, combined with the shoe's geometry and drop, makes the SC Trainer v3 an excellent option for midfoot strikers.

The heel of the SCT v3 is not wider than most models; in fact, we measured it at a very typical 90.0 mm, closely aligning with the average running shoe. Consequently, we believe that neutral runners who strike with their heels will find this shoe quite suitable, but those requiring more support might not find the ride as enjoyable.

Using a carbon plate in a training shoe often risks making it too stiff. However, the SC Trainer v3 employs a plate similar to that of the Elite v4, known for its flexibility despite being carbon fibre-based. And we found it scored just 36.8N in our 90-degree bend test.

This configuration makes it snappier and somewhat stiffer compared to plateless options, yet not as aggressive and rigid as most carbon-plated shoes on the market. In our view, this strikes a good balance, making it a positive feature of the SC Trainer v3.

We conducted a second freezer test to assess how stiffness varied in cold temperatures and observed a 25.3% result, which is satisfactory. The inclusion of PEBA in the FuelCell material has clearly yielded positive outcomes!

Here's another aspect of New Balance's SC Trainer evolution that leaves us baffled. The first generation was notably heavy at 10.5 oz, and the second generation dropped significantly to a more manageable 9.3 oz.

Now, the latest version settles in the middle at 9.8 oz or 278g. While not a deal-breaker, this weight is still heavier than many performance trainers that boast even higher stack heights, like the On Cloudmonster Hyper. It undoubtedly feels like a step back for us.

While we were initially impressed with the look and feel of the FANTOMFIT upper, its durability falls short.

After applying our Dremel tool with 3.2N at 5K RPM, we quickly discovered that the soft mesh couldn't withstand the stress, disintegrating almost instantly. This resulted in a teeth-grinding score of 1 out of 5 for durability here in our lab.

While we were initially impressed with the look and feel of the FANTOMFIT upper, its durability falls short.

After applying our Dremel tool with 3.2N at 5K RPM, we quickly discovered that the soft mesh couldn't withstand the stress, disintegrating almost instantly. This resulted in a teeth-grinding score of 1 out of 5 for durability here in our lab.

After an initial setback with the SC Trainer v3, we shifted our focus to testing the heel padding—an area that typically raises concerns regarding wear and tear.

Fortunately, the results here were dramatically better. We were thrilled to award a 4/5 after evaluating the resilience shown against our testing tools. This marked a significant improvement that positively impacted our overall assessment of the shoe's durability.

Now, let’s examine the outsole of the SC Trainer v3. We've discovered some partially unexpected news—while the upper was a more comfortable FAMTOMFIT version of the Elite v4, our tests show that the rubber used here is virtually identical to that found in the state-of-the-art racing shoe.

At 68.4 HC, it offers a soft mix that delivers excellent grip on all types of surfaces. We found it performs exceptionally well in wet conditions too, providing ample coverage in both the forefoot and heel areas. The midfoot foam is exposed though, but we believe this shouldn't raise any concerns.

We conducted one final test using our Dremel. Despite the soft nature of this outsole, the resilience it displayed was decent. After our testing, we found only a 1.1 mm indentation, which is not bad for a 68.4-HC rubber.

For those seeking the best in both grip and durability, consider the impressive performance of the Adidas Adizero Prime X 2 Strung. However, be prepared for a higher price tag!

We meticulously measure every aspect of running shoes, and the outsole thickness is crucial for assessing durability. We discovered a result of 3.0 mm, which provides ample material to withstand the usual wear and tear, based on our previous tests.

There are few carbon-plated running shoes on the market priced as competitively as the SC Trainer v3, leading us to conclude that New Balance has set a very fair price, at least in the US market.

However, NB often faces criticism in running forums for using less favourable exchange rates for currencies such as the Euro and the British Pound, which could make the price less attractive in other countries.

One downside the SC Trainer v3 inherits from its predecessors is not a welcome one—the absence of reflective elements. We would really appreciate enhanced nighttime visibility if New Balance introduces a version 4.

The Trainer is designed as a long-distance uptempo companion, positioning it between a race shoe and a daily trainer in terms of speed. And the tongue strikes an ideal balance at 3.3 mm, offering both lightness and comfort—exactly what we expect for this kind of shoe.

We also appreciated the tongue loop that helps keep the shoe securely in place. The overall lockdown is superb, as New Balance has opted for simple punched eyelets instead of a more complex lacing system, which is also our preferred setup.

Priced a bit under 200 US dollars, a non-gusseted tongue would have been a major disappointment. Luckily, we were pleased to discover that it's partially fixed to the sides, enhancing the fit particularly at faster paces. Nice!

This year, we're reviewing numerous New Balance road running shoes and have noted that all recent models lack a heel tab.

The SC Trainer v3 also features a tabless design but includes comfortable padding in the heel area—a detail we really appreciated. Although subtle, this padding is significant; the Rebel v4 had fit issues in the heel, and this addition addresses that concern.

The insole can be removed easily, but we advise against doing so unless absolutely necessary—it's a quality one, perforated and thin.

We also found that replacing it with a thicker insole could cause issues due to the shoe's low-volume toebox.