Foxfolk Launches Dirtskirt Lower Linkage Frame Protection

Press Release:Foxfolk

So you’ve just bought a shiny new modern geo Trail/Enduro carbon mtb and you’re beyond excited. It’s expensive, beautifully designed and incredibly well engineered, but as bike designers squeeze 29’’ wheels combined with short chainstays to create phenomenal handling full squish bikes - a new problem is born. Debris flies through the rear wheel, rocks and mud enter the loam shelf. As the swingarm goes through its travel, trapped debris in that small tight space can act as a nutcracker which can lead to frame damage, or even worse, catastrophic cracked frame failure.

Why does this matter if you have new bike warranty? Well, unfortunately mtb brands deem this particular issue as wear and tear, so it's not covered by any bike warranty! This can result in the rider having to shell out several thousand for a new frame or alternatively a complex and costly carbon repair. As well as the inconvenience of riders being without their bike in the middle of their riding season, while trying to source a new expensive replacement frame or repair.

Our team at foxfolk™, a New Zealand based mtb product innovation company, set out to solve this problem, offering riders full peace of mind while riding and saving them potentially thousands along the way.


After testing 186 prototypes on the trails of Queenstown, we’re excited to announce we have launched The Dirtskirt™ which features a proprietary acetate-backed EVA laminate designed to adhere and flex around the bike’s main lower linkage pivot. This prevents mud and stones from getting trapped in the dreaded loam shelf, and eliminates the risk of frame damage and breakages caused by trapped debris in the lower linkage. We think of the Dirtskirt™ as an affordable insurance policy, for a worldwide non-warranty covered problem.


The Dirtskirt™ uses the highest density of EVA foam available on the market; we chose it for its high impact resistance as well as its malleability, which is important to enable the double curvature bend required as the rear wheel is pushed through its travel.


There are no zip ties or velcro straps involved here, just premium grade 3M VHB foam tape. During our 18 month R&D of the Dirtskirt™, we tested 57 different adhesives to ensure the product can absorb significant shock from suspension movement as well as withstanding any form of debris, mud, water, heat, cold and humidity across vastly different climates around the world. Our final adhesive selection is commonly used in the aviation/automotive industry. We had local pro riders testing the Dirtskirt™ for 250+ days, over two full mtb seasons, and the Dirtskirt™ product never came off any frames.


Frame Compatibility
The first Dirtskirt™ SKU is custom designed for 2019-2022 Stumpjumper carbon and 2019-2022 Stumpjumper EVO carbon frames. Why is it not a generic fit product? The reason why, is due to the design of lower linkages between bike brands being predominantly asymmetric from left to right, front to back and often off axis in design. To add to the challenge, different bike brands use completely different suspension kinematics based on licensed linkage patents. Combined, these variables create a rather tenuous R&D challenge.

The good news for non Stumpy riders is foxfolk™ have a more generic fit Dirtksirt™ V2.0 in development which will fit a large range of bike brands and frame models - we’re super excited moving towards launching V2.0 in the last quarter of 2022.

Pricing & Availability
The Dirtskirt™ retails for $29.99 USD and is available now, shipping worldwide from our direct to consumer website www.foxfolk.co.

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