Looking for a shoe that kicks butt for swim running or tackling obstacle courses? The IceBug Zeal3 RB9X is a specialized Top Pick that performs well in the nastiest stuff. The stand-out features are its ability to go from water to trail without worry. Swim running is a sport where athletes will swim from one land mass to another, then run overland. In this sport, a shoe that dries quickly and is less absorbent is best for protecting feet. Of all the options tested in this review, the Icebug is perfectly suited. It has been engineered to take out water-absorbing elements such as lots of cushioning or absorbent uppers. While IceBug claims that this is a “non-absorbent” shoe, it's not wholly true. It wicks away water well, but when it gets completely submerged, it absorbs a little bit of water. In fact, when taking this shoe for a river hike, then running home, the water stayed inside of the shoe, sloshing around for five miles. As a result, we think the drainage system could be improved. That said, no other shoe in this review wicked materials away as well as the IceBug. Also, consider it for multi-sport days or canyoneering.
In addition to its superior ability to wick away the nasty, it is also super lightweight! Its thin rigid synthetic upper, while not very comfortable, sheds mud and protects feet. Even though this shoe has little cushioning, it boasts fantastic sensitivity and traction. The outsole is burly and composed of an ultra-sticky rubber that sticks to submerged rocks and roots as well as super slippery steep slopes. While this is one of the lowest scoring products in this review, it deserves a Top Pick because of its superior performance and specialized niche for swim running.Icebug Zeal3 RB9X - Women's Review
Our Verdict
Our Analysis and Test Results
The Icebug Zeal3 RB9X stands outs for its outstanding performance in water, mud, and snow. The synthetic upper wicks away all of this gunk, absorbing little water on the trail. It's best for any sport that might require a quick-wicking or little water absorption. It receives a Top Pick because its perfect for trail events that might take on obstacles or transitions from land to water.
Performance Comparison
Foot Protection
Traditional foot protection by way of ample cushioning, protective uppers, and a rock plate does not exist in this shoe, but it actually does an amazing job protecting feet from the elements. While running on trails, we could feel all things underfoot.
The outsole is made of a hard RB9X rubber textile that protects from sharp spine or rocks. However the thin upper textile is penetrable to these sharper trail objects…so be careful. That said, the synthetic upper does an fantastic and superior job wicking away mud, water, and snow. In fact, when trudging through sticky mud, it simply slid right off.
While this is a fantastically lightweight shoe is quick to dry with superior wicking power, when water gets in, it sucks at draining. We went for a stream/river hike, took a swim, then ran afterward to see how it would perform. After getting out of the water, we noticed water sloshing around in our shoes for the rest of our run (roughly 5 miles).
When we finally got home, there was no water in the shoe, but it had been absorbed by the liner material and our socks. That said, this shoe definitely has a superior ability to wick water, but it's not impermeable to it, nor is it waterproof. This shoe could be made better by a better-designed water draining system (especially since they are marketed towards water use). As a result, it scores a score of five out of ten as it less protective than other shoes on the market, despite the amazing upper and liner materials.
Traction
The traction on this shoe is bomber! Icebug's RB9X rubber textile is a harder composite that does a great job on super soft surfaces like gnarly mud piles, sand, and snow. When running on pavement, the lugs didn't provide an ideal transition that you'd experience with a flatter shoe, but the lugs held up on it. So, we think it's okay for cross-over terrain where road sections are limited.
When tackling steep mountainsides and zoomy single track, the long V-shaped lugs on the forefoot and heel performed impeccably, biting down on the trail, without slipping out or sliding sideways.
The tiny spikes at the arch provide additional stability over a variety of surfaces. While practicing river crossings, the hard rubber composite sticks to submerged rocks, giving us confidence over that kind of terrain.
Overall, this outsole performs on a plethora of surfaces from the most technical to the roads.
Stability
Stability is not the best, but it's not bad either. The narrow construct of the shoes platform and outsole result in a narrow base to the shoe that is actually smaller in width than the upper that wraps around the foot. As a result of this narrow base, it's not as stable over technical surfaces.
When nimbly finding our way over a rocky trail, we found ourselves braking and in some cases, almost going over the edge of the shoe. That said, the upper is thin and flexible, providing a very precise fit and better balance overall.
Comfort & Fit
This shoe does not boast comfort and features a narrow fit. For comfort, there is very little cushioning in this shoe. While there is a little extra in the heel (for potential heel strikers), the forefoot is super bare bones. We could feel everything on the trail, and after just a few miles our feet were tender and sore.
The upper is made of a super stiff synthetic material that does an excellent job wicking and promoting breathability. The tongue, if not adjusted properly, can result in a pinch point around the ankle.
While the upper is thin, it's not very flexible. Some of our testers noticed a little chafing around the ankle when worn with thin ankle socks, so we'd recommend taller socks. In addition, because the upper is so stiff, there is very little give, so hot spots can develop if the shoe doesn't fit nicely. Overall, the comfort elements really aren't there when compared to other contenders.
This shoe easily fits a narrow foot best with a 'true to fit' size. The length of the whole shoe feels super narrow, even in the widest portion of the shoe. It also doesn't have a lot of volume from top to bottom. When running on trails, our medium and wide footed testers were not happy with the cramped and confined fit. Though, our narrow footed testers, or those that preferred a narrow shoe, liked it.
Weight
The 8 is one of the lightest trail shoes on the market. Weighing just 7.0 oz, it feels like there's hardly anything on your foot. In addition, this shoe is marketed to be 'non-absorbent'. While this claim is a big one, it's not entirely true. When running around in streams and submerging them in water, the shoe did absolutely absorb water. However, it was minimal, and the shoes dried super fast! In our official submersion tests, it only absorbed a mere 1.6 oz of water which is fantastic!
Sensitivity
With a few protective elements and hardly any cushioning underfoot, this shoe is very sensitive. While it's not super flexible, you can certainly feel sharp rocks, sticks, and any undulation in the trail surface. If this is what you seek, it's a great option! It scores nine out of ten.
Best Applications
With superior construction to battle the elements like water, snow, and mud, this uber-lightweight shoe is perfect for any sport that might see all three. This includes swim running, obstacle courses, super mucky or dirty trail runs, or simply running in the rain. It's not our favorite for long distances, but could certainly hold up if you want to use them for that purpose. If you prefer a super sensitive option that doesn't boast a lot of cushioning but has a super protective upper, bomber traction and absorbs little water, this may be your next trail runner!
Value
This specialized shoe retails for $150. If you seek just a regular trail runner, there are better shoes with better performance and a lower price. However, if you're specifically looking for a shoe like the Icebug (quick to dry and performs well in water), then the price is worth it. In terms of durability, we didn't notice any wear issues even after swimming, running, then swimming again. Overall, middle of the road value, but still a high sticker price.
Conclusion
The Icebug Zeal3 RB9X is a unique trail shoe that is specialized for use in water. If you're a looking for a shoe that does great during obstacle course races or water sports like for swim running, this is an excellent option! Despite its lower overall score in this review, it performs well across many key metrics for this function.
