BURSTThe footage shows a climbing shoe sticking on a vertical rock wall, seemingly glued to the surface.
“Are you kidding me?” A voice behind the camera is clearly in disbelief. That person wasn’t the only one who felt that way, as the video has since attracted 1.4 million views to date.
It was a spectacular product showcase of a new breed of climbing shoe rubber called GP1, which is made from retired F1 racing tires.
The manufacturer, RAToM, headquartered in Japan, is a new competitor to the rubber market, which has traditionally been dominated by the likes of Vibram, 5.10, and, more recently, Unparallel.
The demonstration sparked both awe and disdain about what looks to be a groundbreaking development in the role this new material will play in the future of the sport.
Perhaps the most obvious question is whether the rubber, if it is as effective as shown, will impart unfair advantages to those wearing it.
Some are calling it aid, especially in the context of no-tex holds and slab climbing. Will precise footwork become a lost art?
Others say it will be a tool that will help climbers unlock new levels of potential.
At the moment, officials have not taken a firm stance on the matter.
The most recently published set of competition rules for World Climbing, formerly known as the IFSC, state that: “Unless allowed by applicable competition regulations, competitors are prohibited from: A) using any substance or equipment that modifies the condition of holds or the climbing surface. B) wearing gloves or kneepads.”
Gripped asked World Climbing if the new rubber is considered legal for competition climbing, and so far, there does not appear to be a definitive answer.
“Shoes would need to be commercially available and in good condition,” wrote Richard Aspland, media manager for World Climbing.
“There are currently no ‘in-depth, specific’ requirements other than this at present. However, as with everything we do as the International Federation, we will monitor and amend any rules and regulations, etc., that affect our competitions and the sport – something which becomes more commonplace as the sport grows and technology such as shoe design performance evolves.”
At the moment, the new GP rubber is available for resole, but there don’t appear to be any shoes on the market that come with this material out of the box.
Aspland did not immediately respond to a follow up question about whether GP rubber fit the definition of “commercially available.” Gripped will update the story if a response is received.
Gripped also reached out to the new Pro Climbing League, but did not immediately receive a response.
Meet Max Fisher of Rhythm Resoles: the man behind the viral sticky rubber demonstration
Fisher, the owner of the Flagstaff, AZ-based resole shop, has been perhaps the most effective proponent of the new GP rubber.
While others have previously showcased the material, Fisher’s shoe-sticking-on-wall demo brought the new material’s profile to new heights, attracting 1.4 million views to date since it was posted in December.
Fisher’s business is a RAToM partner and resoles shoes with the new rubber.
Gripped had a lengthy email correspondence with Fisher to get an idea of what the new rubber was capable of and whether pro climbers were already embracing the product. What follows is the conversation, edited for clarity and brevity.
Gripped: You don’t have to name names, but are you hearing from pro climbers looking for this rubber?
Fisher: While specific names can’t be shared, there are already multiple top-level climbers using GP rubber on their shoes. Feedback so far has been overwhelmingly positive, and there’s growing interest from other high-level climbers who have reached out to learn more or try the rubber for themselves.
The rubber has clear appeal in competition settings as well. It shows strong potential for speed climbing and has proven capable of holding its own in certain bouldering competitions, which helps explain the increasing attention it’s getting from the professional climbing community.
Gripped: Aside from the fact these are retired F1 tires, can you tell me more about the specs of the rubber compound?
Fisher: While RAToM can’t disclose specific formulation details, each compound undergoes extensive real-world testing before reaching the market.
Rather than chasing stickiness alone, they focus on meaningful performance factors such as friction, temperature stability, edging support, and durability.
RAToM’s compounds are clearly defined by intended use and Shore hardness, ranging roughly from 55A to 65A, allowing climbers to choose rubber optimized for the conditions they actually climb in.
Gripped: What temperatures does it work best in? What are the temperatures where it will fail?
Fisher: RAToM compounds are designed to perform across different temperature ranges, and rather than prescribing a single “ideal” temperature window, each rubber is categorized by the conditions where it excels.
GP1 (soon to be renamed GP1-Soft) is optimized for cold conditions and outdoor winter climbing. It remains soft and adhesive even in freezing temperatures, where many rubbers begin to harden and lose friction. That same softness makes it less suitable for hot summer climbing, where excessive heat can cause the rubber to feel overly soft and compromise performance.
GP1-Pro (soon to be renamed GP1-Hard) occupies the middle ground. It performs well across a broad temperature range and particularly shines in neutral, controlled environments like indoor gyms, making it a versatile option for climbers who move between seasons or primarily climb indoors.
GP2 (soon to be renamed GP2-Hard) is the stiffest compound in the lineup and is well suited for high-temperature outdoor climbing. It maintains structure and edging precision in summer heat, where softer rubbers can feel vague or unstable. GP2-Hard, in particular, has developed a strong reputation for midsummer performance, though grip can diminish as temperatures drop into late fall and winter.
Letting customers choose their soles based on the season can also be one of the fun aspects!
Gripped: Are there any downsides or weaknesses to this rubber?
Fisher: The two biggest downsides right now are price and availability.
Because of the manufacturing process and the amount of hands-on labor involved in producing the rubber, GP Rubber comes in at a higher cost than many existing market options. Additionally, because the rubber is manufactured in Japan, availability can be more limited outside of that region.
That said, both of these are challenges RAToM is actively working to improve. As production scales and distribution expands, their goal is to make GP Rubber more accessible without compromising the performance that defines it.
Gripped: GP1 seems to be sold out on the RAToM site. How much demand are you experiencing for this?
Fisher: Demand for GP1 has been extremely high. The recent hold up was largely due to the rubber being held up in customs during transit from Japan, which created a temporary backlog. That shipment has now arrived in the U.S., and Rhythm Resole is actively stocking up on all GP compounds.
With demand continuing to rise, a limited slot preorder will be opening soon! I’m very excited to be able to offer this rubber to climbers.
Gripped: The stickiness you demo’d in your video seems INSANE. How will this change the world of climbing? I feel like there will be a lot of people saying this is aid.
Fisher: The “this is aid” reaction is totally understandable. But GP Rubber isn’t a gimmick, it’s friction. Every climber already wears climbing shoes, and this is just another evolution of that tool, not a shortcut around skill. Climbing footwear has changed dramatically over the years, from aggressive downturns and asymmetric lasts to thinner midsoles and softer compounds, and each of those innovations initially sparked similar debates. GP Rubber doesn’t change the rules of climbing; it refines consistency and reliability underfoot. By improving friction, it allows climbers to focus more on movement, balance, and execution rather than compensating for unpredictable rubber performance. At the end of the day, no rubber climbs the route for you, ability, technique, and decision-making still matter most.
Gripped: Have you tried this rubber on stuff like no-tex holds, polished slab, etc? Those are the most obvious I can think of this being a real help.
Fisher: GP Rubber performs exceptionally well on polished slab, offering a level of stickiness that’s immediately noticeable underfoot. While slipping is still possible, it’s the most sticky rubber I’ve climbed on. On smooth volumes and other friction-dependent surfaces, it gives climbers the confidence to commit fully to their movements. While I haven’t personally climbed on no-tex holds, RAToM tests especially indoors on no-texture surfaces and shows that the rubber excels there as well. According to them, it almost feels like it “brings texture back” to the holds, providing traction where other rubbers might struggle.
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