The Climbing Shoe Rubber Comparison
Everything you need to know about the best climbing shoe rubbers.
Last updated on April 20th, 2023 at 10:57 am
Have you ever spared a minute to think about climbing shoe rubber? You probably should, understanding a bit about your rubber might just help you climb harder.
Unless you are climbing barefoot like Charles Albert, the rubber your climbing shoes use is going to have a big impact on your climbing. Without the right rubber, achievements like Nalle Hukkataival sending V17, Adam Ondra leading 9c or Alex Honnold free soloing El Capitan would surely be impossible.
In homage to this unsung hero, we have created a beginner’s guide to the confusing world of shoe rubber. Here we will dive into the history of climbing rubber and take a look at some of the best climbing shoe rubbers available today.
What is Climbing Shoe Rubber?
The rubber found on modern climbing shoes is made from a mixture of synthetic compounds. While fillers like clay and carbon black are common ingredients in the rubber manufacturing process, every brand has its own highly secretive formula that they use to make its trademark rubber.
Today, there are dozens of rubber compounds designed to excel in the vertical realm. This wasn’t always the case though.
The climbing rubber revolution has its roots in the Victorian ages. In the early 1800s, a time when recreational mountaineering was starting to become popular, daring adventurers used boots that were made entirely from leather (yes, that includes the soles of their shoes too).
It wasn’t until Charles Goodyear discovered vulcanization (a process that increases the strength and flexibility of latex) in 1844 that the trend of using rubber for shoe construction started to take off.
When rock climbing started to emerge in the early 20th century, it was only natural for the rock pioneers to use their bulky mountain boots. It didn’t take long for climbers to realize the need for specialized shoes, which lead to early ground-breaking models like the PA boots in the 1950s.
If there is one shoe that really pave the way for the future of climbing shoe rubber, it was the Boreal Fire. The Firé was released in 1979, and amongst a host of other new shoe technology, Boreal unveiled the first rubber specifically designed for climbing.
This marked a huge step forward in climbing shoe construction. In fact, the shoe was so revolutionary that the climbers reported jumping an entire grade after using them.
Soft vs Stiff Climbing Shoes
MYTHBUSTING: It is a common misunderstanding that the outsole rubber creates the rigidity of a climbing shoe – this isn’t true! Although the outsole rubber does have a role to play, it is predominantly the midsole that has the biggest influence on how flexible a shoe is.
That said, all rubber compounds come in varying levels of stiffness. Both soft and stiff rubber have their benefits and downfalls which ultimately have an impact on your climbing.
The pros know this, that’s why Adam Ondra climbed Silence (the world’s first 9c) using both the La Sportiva Miura and Solution.
So, now you know that the rigidity of a shoe is controlled by the thickness of the midsole and the rubber outsole, which type of shoe is right for you?
Deciding between soft or stiff climbing shoes ultimately comes down to what you are standing on.
Stiff Climbing Shoes
Stiff climbing shoes usually have a thicker midsole and more rigid outsole rubber, which create a sturdy platform for you to stand on.
While a stiff shoe will certainly decrease sensitivity and reduce how well you can “feel” the rock, the unyielding strength of a stiff shoe is ideal for inspiring unwavering confidence on the smallest of holds.
Sure, stiff shoes won’t do you any favors on a dynamic bouldering problem but the thicker rubber will inevitably last longer than a wafer-thin sole of sticky rubber.
Best For: Trad and big-wall climbers tend to favor stiffer shoes as they reduce strain on your muscles and ligaments making for a comfortable experience.
A note for the newbies: If you are new to climbing, a stiffer shoe will help you to start developing your muscles, ligaments and technique. The strain climbing put on your toes is significant, so make sure to build up experience a bit before moving to the ultra-soft shoes.
Soft Climbing Shoes
Soft climbing shoes are designed so that is as little between you and the rock as possible.
This makes them extremely sensitive and allows the shape of your foot to conform to the shape of the hold you are standing on. Think of these shoes like sticky rubber socks. They are ideal for smearing or hooking, or when force is being applied
Unlike their stiffer counterparts, there is little support in these shoes, so your foot and leg muscles are working harder when you weigh your toes. These shoes are more suited to bouldering or single-pitch climbing.
Best For: Soft climbing shoes are ideal for climbing large volumes in indoor gyms, or for hooking pockets on steep overhung routes.
A note for the newbies: Soft shoes are really good for developing footwork and will make you a lot more aware of your positioning and balance.
To summarize: At the danger of sounding like a broken record, the ideal rigidity of a shoe depends on what you are standing on. If you are working on a vertical route with microscopic footholds, a stiff shoe is what you need. If you are working on a monstrous overhang, you will want a soft shoe that will conform to the hold to allow for maximum friction.
Types of Climbing Shoe Rubber
One of the most debated topics in the world of climbing shoes is the type of rubber your shoes are packing. The type of rubber will directly affect the grip, durability, and edging ability of your shoes.
Shoe manufacturers recognize the importance of high-quality rubber, which is why companies like Vibram and Five Ten have spent millions of dollars developing their secret rubber formulas.
While there’s a pretty extensive selection of climbing shoe rubber out there, there are certainly some front runners in this race.
Here is the best climbing rubber that can be found on shoes right now.
Vibram is the king of mountaineering rubber and has been since 1937. The company was created after several friends of the company’s founder, Vitale Bramani, died in a mountaineering expedition in the Italian Alps. He thought that poor quality footwear was partly to blame for his friend’s deaths, so Bramani spent the next two years developing a high-quality rubber that would be more reliable, even in the toughest of terrain.
It wasn’t until 1988 that the company introduced Vibram Grip, its rubber specially designed for free climbing. Ever since then, the world has been blessed with many Vibram climbing shoes.
Vibram XS Grip – A performance rubber that is designed to help you climb at your best on any rock surface. Semi-stiff in nature, XS Grip is used by over 10 shoe manufacturers including La Sportiva, Scarpa and Tenaya. This compound has been favored by plenty of pros over the years including Daniel Woods and Alex Megos.
Vibram XS Grip 2 – The Grip 2 provides superior grip and durability than that of its predecessor. Designed to excel on overhang climbing, it’s softer than the XS Grip but still retains a great balance between edging and smearing capabilities. This is one of Vibram’s most exclusive compounds and is only found on La Sportiva’s and Scarpa’s high-performance shoes. The XS Grip 2 is ideally suited to aggressive sport climbing and bouldering shoes.
Vibram XS Edge – Widely known as one of the best edging rubbers in the game, the XS Edge is ideally suited to big wall climbing and multi-pitch routes. While it’s stiffer than its counterparts, the rubber has found its way into some of the most popular bouldering and all-around climbing shoes including the La Sportiva Miura and the Scarpa Instinct VS.
Vibram XS Flash – The newest rubber to enter the Vibram family is the XS Flash. Designed specifically for indoor climbing and plastic walls, this non-marking rubber is extremely soft and provides a great level of friction.
Note: A lot of climbers ask about Vibram XS Grip VS XS Grip 2 VS XS Edge. These are all tried and tested rubbers that are made for different purposes. The XS Edge is certainly a lot harder, so will perform better on small areas of contact than that of other Vibram compounds. XS Grip and Grip 2 are made for different purposes too. The XS Grip is built for more general use and the XS Grip 2 a softer, sticker compound that is focused on performance.
Stealth Rubber (Five Ten)
The late Charles Cole, founder and former president of Five Ten, was the man behind the legendary Stealth rubber, an invention that shook the climbing world.
As well as a cult-like following and a host of celebrity fans, the rubber has been dubbed the highest-friction rubber in the world by some of the biggest outdoor publications including; Rock and Ice, National Geographic Adventure and Climbing magazine.
With a fanbase like that, you know Five Ten are doing something right. Five Ten now manufacture 3 rubbers:
Stealth Mi6 – Stealth Mi6 excels on overhung routes and is known as some of the stickiest rubbers ever. A super high friction rubber that can smear on even the most polished rock. The trade-off with this rubber being so soft is that it is not very durable. It’s not uncommon to hear fellow climbers at the crag complaining about the very short lifespan of their Mi6 shoes.
Stealth Hf – The Hf rubber is found on Five Ten’s performance shoes, such as the Team and Dragon and has been on the market for over 10 years. This soft rubber comes into its steep, overhung sport routes and bouldering problems. Similar to the Mi6, this high-friction, sensitive rubber will wear fast. Like very quickly.
Stealth C4 – The C4 is the most commonly used rubber in the Stealth arsenal and the one that originally brought Five Ten a legion of loyal followers. This compound delivers a more durable rubber than the other Stealth compounds and can be compared to the Vibram XS Grip 2, but perhaps with a little less durability. It’s found on some of their much-loved shoes including the Anasazi and Moccasym.
Trax Rubber (Evolv)
While Trax may not be as popular as Vibram or Stealth, don’t be fooled into thinking this is a second-rate rubber. Developed by a team of boffins with Ph.Ds in rubber science (yep, that’s a thing) this rubber has been used by some of the greats – Alex Johnson and Ashima Shiraishi to name a few.
Evolv has developed a range of Trax rubber to adapt to different environments.
Trax-SAS – This semi-stiff compound is the most popular Trax rubber, which can be found on the vast majority of Evolv shoes. Trax-SAS maintains a balance between friction and durability and is designed to perform on rock and plastic holds across a wide range of temperatures, making it a great all-round rubber.
Trax-XE – Found on a few of their newest shoes – including the General and Supra – this super stiff rubber is designed specifically with edging in mind. Found on their ultra-performance shoes, this rubber is undoubtedly in its element on granite and slab walls and is easily one of the most durable rubbers on the market.
Trax-GT – The newest addition to the Trax family is the GT rubber, cooked up by the Evolv labs with the sole purpose of plastic and gym climbing. This long-lasting, non-marking material isn’t found on many of their shoes – yet.
FriXion Rubber (La Sportiva)
Vibram (XS Edge and XS Grip 2 in particular) rubber is found on many of La Sportiva’s performance shoes. However, often La Sportiva’s more affordable models feature their FriXion rubber. La Sportiva has been developing their FriXion line to consist of 5 different compounds, of which only two are currently used for climbing shoes, with the rest being used on their running and approach shoes.
FriXion Black – Their stiff FriXion rubber which is used on budget shoes including the Tarantulace and the Oxygym. Described as an ‘ultra sticky performance compound’ that puts performance over durability. From our experience, we find that FriXion black tends to perform better on plastic than rock.
FriXion Eco – The FriXion eco performs very similarly to the black, but uses recycled components and offcuts from production that would usually have to be discarded. This rubber is found on La Sportiva Eco shoes including the Cobra Eco and Mythos Eco.
FriXion White – A recent addition to the FriXion family is the White. Similar to the Trax-GT, this is created as a non-marking durable rubber designed for indoor climbing. As of yet, no La Sportiva climbing shoes come standard with FriXion White, but we are looking forward to seeing what creations La Sportiva cook up with this rubber in the future.
Climbing Shoe Rubber Comparison
Ever since the first climbing shoes touched rock, climbers have been debating which shoe has the stickiest rubber. Unfortunately, comparing and coming up with a definitive answer to this question isn’t as easy as it sounds.
The reason for this is because temperature, weight and surface all impact the ability and effectiveness of the rubber. Different rubbers are also designed for different tasks and surface types.
It also depends on what you class as the best. While there are certainly some rubbers that are stickier than others, they will almost certainly be less durable than their counterparts.
There was an experiment done in 2007 by Steven Won – a professor at Northwestern University’s Department of Physics and Astronomy – that attempted to determine the stickiest climbing shoe rubber.
The experiment involved comparing 9 of the most popular climbing rubber (at the time). The method involved cutting a 2×2 inch piece of each rubber and placing them on a flat rock. A weight was then put on top of the rubber and the angle of the rock was increased until the rubber slipped off. The angle at which the rubber slipped was then recorded and the experiment was repeated on a flat concrete hold.
Based on this, Steven Won concluded that the following rubbers had the best friction:
1) Evolv Trax XT-5
2) La Sportiva FriXion
3) Vibram XSV
4) Mad Rock FX5
5) Vibram XS
6) Stealth HF
7) Stealth C4
While this experiment was a good start at comparing climbing rubber, the results of this experiment are debated.
For example, the temperature remained constant across all the experiments but as I have already mentioned temperature has a huge effect on how well some rubbers perform. The experiment could have also benefited from using other types of rock and not just a granite slab, as some rubbers would certainly perform better on limestone or sandstone.
Now You Know!
Congratulations, you now know a thing or two about climbing rubber! Make sure to bore all your friends with all this useless knowledge you have acquired.
While your friends might not benefit from this information, your climbing just might. Next time you are being shut down on those fiddly micro footholds, why not slip on a pair of stiff pair of climbing shoes? Or if your current rubber just isn’t making the cut, why not try another one out?