Adidas Prime X 2 Strung Review: A Tall, Chaotic Super Shoe Grows Up

Introduction

The adidas Prime X 2 Strung is a complete redesign of one of the most chaotic, exciting running shoes ever made. The original Prime X built its reputation as a gigantic, rule-bending trainer that felt like nothing else, particularly for fast long runs. This version keeps the outrageous 50mm stack height but reworks nearly everything around it, from the rocker geometry to the upper.

The result is a shoe that is more capable at faster paces and more confident over long distances, but slightly less wild in the process. At $300, it sits firmly in premium territory, so it is worth understanding exactly what changed before committing.

Who This Shoe Is For

The Prime X 2 Strung remains a 50mm stack shoe, which breaks the World Athletics rule that limits shoes to 40mm of height and a single carbon element. In practice, that rule only matters to elite runners who have to submit equipment for inspection or who are chasing prize money and records. For everyone else, the extra stack is simply a huge amount of cushioning and propulsion to play with.

Inside that stack sit roughly two and a half layers of Lightstrike Pro foam and two carbon fiber plates, both visible through a layered cutout window in the outsole. Between the two plates, toward the forefoot, sits a small wedge of foam that acts like an airbag in a car suspension: compress it along with the plates and the release delivers a satisfying pop. The drop measures 6.5mm, down from 8.5mm in the previous version, which leaves 43.5mm of forefoot stack compared to less before.

Main Strengths

The most meaningful change is the rocker. The angle of attack at the front of the shoe is slightly more gradual but starts earlier, and on foot it makes the shoe noticeably more aggressive. In the previous version, fatigued later miles could feel like being stuck midfoot, with too much shoe in front and a struggle to get turnover. The earlier rocker in the Strung 2 makes it easier to get onto the toes and pick the heel up, which should help tired legs keep rolling.

The second strength is pace range. Last year’s shoe was excellent around marathon effort or slightly slower, but the heft made anything faster feel clunky. This version has been taken through threshold workouts and marathon effort miles with strong results. The faster you go, the more the weight shows up, but this is now genuinely a shoe for faster threshold work, not just steady long running.

The double carbon plate also makes the shoe more responsive to form. Run clean, tall, and efficient, and it rewards you with lively feedback. Let the form slip and it stays forgiving, but the excitement fades, almost like a nudge to run better. The Lightstrike Pro and plate combination also feels more stable and controlled than before, thanks partly to a slightly flared heel and midfoot, which makes soft foams feel a touch denser. That is less dynamic on each foot strike, but it is less scary for midfoot and heel strikers.

Things to Consider Before Buying

The weight is the first honest trade-off. The Prime X 2 Strung comes in at 10 oz or 283g, up from 9 oz or 255g in the previous Strung version. Given how much shoe this is, it is not terrible, but it is a real number.

The lacing system is the more frustrating change. New rubber grommets at the topmost lace loops seem designed for cranking down on the laces, but they are less elegant than before and the laces shift around more, since the grommets are less grippy than the regular loops. Prior versions held lacing without issue, and this one constantly feels like it is moving while running.

There are wins in the upper, though. The tongue is now a sewn-in knit material that turns the shoe into more of a Strung knit bootie, and the three stripes are woven into the upper rather than looking painted on. This is also the first Prime X that is actually easy to put on; earlier versions required wrestling with the tongue before lacing up. The heel cup remains delightfully floppy and unstructured, ideal for fast running, with slightly more bumper padding each generation to keep the ankle locked in.

The Lacing System and Upper Fit

The Strung material itself looks fantastic, with a striking, innovative design, and it held up perfectly in rainy race conditions in the previous version. The complaint is narrow but real: the grommets and looser lace loops make the lacing feel sloppy in motion. The knit tongue and easy entry partly compensate, but if you are sensitive to lacing movement, this is the area to scrutinize.

Buying Advice

At $300, the obvious comparison is the original Prime X, which is still on sale at the same price with little to no discount. Choose the original if you want a slightly lighter shoe and prefer a later-stage rocker that only turns aggressive at the very end; some of that version’s dynamics may still appeal more than the new design.

The wider market offers few true equivalents, since the Prime X is almost a category of one. The ASICS Superblast is the closest: a jumbo stack shoe using racing foam with a layer of daily training foam underneath instead of a plate, making it manageable at a wider range of paces. It is also featherweight by comparison and costs $200, saving $100. The New Balance SC Trainer v2 is a stretch comparison: this year it came in under 40mm, using two layers of racing foam and a carbon plate for a similar long-run and threshold-mile role, at $180, which is $120 less.

If you want the Prime X 2 Strung, get it, knowing you are paying for it. There is nothing else quite like it, though other shoes can do similar jobs for less. All three shoes sit in the ridiculous price range, so dollars-per-performance comparisons stop being meaningful.

How It Fits a Rotation and the Competition

For a big-shoe rotation built around the Prime X 2 Strung, the Saucony Endorphin Elite makes a natural marathon racing partner. It is also a tall 40mm stack shoe, technically race legal, very lightweight, built with two high-end foams and a featherweight upper that breathes and sheds water exceptionally well. For easy and recovery days, the Fresh Foam More v4 offers a huge stack height, a very comfortable and squishy ride in a different way, and the same tall-stack, early-rocker feel you get accustomed to in the Prime X.

That rotation covers workouts, racing, and recovery with a consistent tall-stack feel across all three. It is an expensive way to build a quiver, but for runners who love maximum stack, it is a coherent one.

Conclusion

The Prime X 2 Strung is a fantastic update that turns a wild, chaotic shoe into a more complete one: better for running faster, better for running longer, and more confidence-inspiring for racing. The trade-offs are added weight, a slightly denser and less dynamic feel, and a lacing system that does not live up to the rest of the package. For runners who want the most shoe adidas can legally and illegally put underfoot, it remains in a class of its own.