Under Armour Threadborne Fortis 3 Performance Review

When something works, you ride it hard. Under Armour has found that Threadborne works, so the woven material has been found in nearly every product line for 2017. That’s good for the upper, but does the Under Armour Threadborne Fortis 3 make us happy? Read on…

Under Armour Threadborne Fortis 3 is available now at Eastbay.com

This outsole should be familiar by now because Under Armour has used it on multiple models, starting with the Threadborne Slingflex. Combining a high-abrasion rubber outsole with deep flex grooves in the forefoot, UA has created a long-wearing transition-based runner that feels fast.

(These images were taken after two months of solid wears, both running on roads and treadmill, plus some weight training time. With a little cleaning these could be good as new.)

The flex grooves make the forefoot traction better than expected, allowing the Under Armour Threadborne Fortis 3 to contact the ground at any angle, slow or fast, and let the foot dig into the surface. The cored-out heel area, formed like a suction cup, will actually stick to the floor, road, or treadmill if the shoe is in a compressed state for any length of time.

That feature was strange the first few times the Fortis was worn casually — I was standing on my hardwood kitchen floor and when I took a step I heard an audible “pop” — but when moving fast there is no issue at all. Add water, and the suction becomes more noticeable, but again, don’t stop and it won’t happen.

Under Armour has mastered Charged foam in its running line. If you were a fan of Micro G, then the Charged in the Threadborne Fortis will make you extremely happy. It is stable, responsive, and dense, all at once, and offers the runner a bouncy, cushioned ride. The genius of Micro G was it could be thin but still cushion well. Charged has finally done that for Under Armour.

From forefoot to heel, the cushioning was smooth and the strides were easy. The flexible outsole worked under the thin midsole to feel fast and light while retaining needed impact protection.

On top of that, we get a Charged insole to boost that initial impact, making the feel even more plush and fluffy. Seriously, Under Armour, give us this Charged feeling in the basketball line already!!

Threadborne, UA’s flagship knit, began as a flexible but supportive material on the Curry 3 last fall; it quickly made its way into other categories, especially running, starting with the Slingflex. Where the Curry 3 was a tight, rough knit, the Slingflex was like a sock.

The Under Armour Threadborne Fortis comes somewhere in between. It is still flexible but loses some of the sock-like feel and for a slightly rougher and more durable build. This is lessened some by the use of a full-foot bootie construction, taking away the internal chafing and hotspots — except one. Right over the little toe the last lace hole is sewn in and the rubbing there while barefoot was serious pain. However, it was only while barefoot. Even the thinnest socks took care of the issue.

The Threadborne here is sewn in multiple directions for support, better fit, and flex — and it works. The holes in the weave that are visible in the pictures do go completely through, while the black lines crisscrossing the upper are a tighter weave for better fit and less give. There is very little stretch in the multi-colored parts of the upper, so fit is never compromised by the upper moving out or giving with the foot.

Again, near perfect, which is how a woven shoe should be. Seriously, it’s basically a sock with cushioning, so why shouldn’t fit be awesome?! Length-wise, stay true to size — it may give a little extra in length but after a long run you will appreciate some room for your swelling feet. The forefoot wraps around your toes with little space above, even with thin running socks on. The midfoot is wrapped the same, with the tighter black lines pulling the shoe up solid.

The heel and ankle are where it gets interesting because there is an ankle collar coming up from the internal bootie. We have seen this concept in basketball from Under Armour, from the original Juke to the Curry 3ZER0, and while the structure in the Fortis isn’t as substantial as those shoes, it is still something that works well when used correctly.

This collar is separate from the regular lacing so it wraps around the sides and front of the foot and really pulls you into the heel. This cuts all heel slip and adds some padding in the area to take away lace pressure when laced tight. With the minimal upper movement still pushing hard, a simple collar like the one used on the Under Armour Threadborne Fortis feels great on-foot and even better when running.

One thing the Under Armour Threadborne Fortis is not is supportive. Granted, it isn’t meant to be — this is a neutral and fast runner, so no surprise. What is here works though, from the internal ankle collar to the solid lacing system. The low ride lets you run on some uneven surfaces — not recommended for full-out trail running — with no issues, especially with the heel lockdown being so good.

The heel cup is, well, there isn’t one. The weave is a little stiffer and there is a fuse backing around the heel cup, but it won’t keep you upright in bad situations and is more for structure and fit. If you land on uneven surface or need some extra support for pronation, sorry, not happening here. There is no internal shank in the midfoot so plantar fasciitis sufferers beware. All of this sounds negative, but again, the Under Armour Threadborne Fortis is a fast, flexible runner, not a high-structured stability shoe. Know what you need.

For the past two years, the best runner Under Armour released was the original Speedform Gemini. The Under Armour Threadborne Fortis has moved into that slot, using a flexible yet durable upper woven material and a seriously cushioned midsole. If you have been holding off from trying UA runners for whatever reason, hide no more — the Threadborne Fortis is a shoe that can compete with any shoe in the nuetral training category.

My only real complaints are the lack of support, which again, is not what this shoe is made for, and the Threadborne is a little rough, which was easily fixed by socks.

Under Armour has made amazing strides in its footwear category in the last four years and has made it clear that it is serious about performance. In the notoriously faithful history of running, where lines like the Kayano and the Pegasus are over 20 and 30 models into their lifespans, consistency and longevity is key to consumers. The Under Armour Threadborne Fortis is only on model number three, but if the evolution of the model continues, Under Armour could have its first lifetime achievement model.