Rimpact Explained
The Technology
There is more to a good tyre insert than meets the eye. We learned this the hard way, buying some off the shelf foam, shaping it and proceeding to wreck our wheels. We've tested prototypes, learned, redesigned and tested again. And again. And again. Four years later the result is a range of high performance products that are unique in providing an improvement in performance without any of the draw backs tyre inserts are often associated with.
The Foam
Lightweight, Highly Impact Absorbent, Doesn't Absorb Sealant, Can Withstand Repeated Impacts
Not all foam is created equal. We tested many different foams and met with an Industry Leading Manufacturer to narrow down the best options available. Eventually after months of dead ends, we found it. The holy grail of High Density, Closed Cell, Cross Linked, Polyethylene Foam.
High density - Dense enough to absorb energy but not so dense as to pass that energy through to your rim.
Closed cell - Does not absorb Sealant.
Cross linked - Superior Torsional Strength to resist tearing and stretching.
Polyethylene - Inert and carbon coloured to prevent dye releasing into or reacting with latex based sealant.
Vibration absorbing - Capable of deadening high frequency vibrations propagated through the tyre carcass, into the rim and felt through your hands.
Tool free - Capable of being manufactured into a loop without zip ties or straps. No hard bits in your tyre that can snap or fail.
The Valves
Compatible with Inserts, High Quality, Aluminium
Many Insert designs require a modified Presta valve to allow free movement of air without the Insert blocking the valve's air passage. Rimpact is no exception and this is the case because we believe that a small change in valve design allows us to achieve an uncompromising Insert design. By exhausting air our of the horizontal air ports Rimpact valves don't block, even when the insert shifts. They work with sealant injectors, have removable cores and can be run in a regular tubeless set up to boot!
The Shape
Carefully Thought Out, Simple but Effective
Why are Pneumatic tyres prevalent in all forms of transport, even in high level Motorsport? The reason is simple, air. It's characteristics are tune-able to weight, tyre thickness, terrain, temperature, speed, altitude, traction etc etc.
By filling a tyre in its entirety, with a material less tune-able (like foam), the tyre's ride characteristics become less controllable. In testing we found our bikes to feel less confidence inspiring, traction to be more inconsistent, and vibration to be higher. Our test crew noted tyres would deflect off of roots and rocks rather than deform and track. We believe this is due to excessive foam in the tyre preventing the carcass from deforming as it needs to.
We prototype tested many different volumes to determine the sweet spot where vibration dampening, grip and impact protection increased to a maximum whist deflection, harshness, and vagueness decreased to a minimum level.
We also looked at how the shape of the foam could impact ease of fitting as well as improve side wall support. Pushing the envelope until we went too far, then dialing it back to a manageable sweet spot helped us create a "best of all worlds" design!
Dual Density
Rimpact CX, PRO and EDH
Rimpact ORIGINAL has been proven. There's no doubt about that - piloted to multiple Top 10 results and a stage win in the EWS under racer Matt Stuttard. But despite this we knew there was a way to improve upon our design.
Our extensive testing concluded that, increasing the density of the material does not equal an increase in performance, as explained here. This is why helmets aren't as hard as rock and why knee pads are stiff but supple. As you'll learn, an increase in density past a certain point began to transfer force through to the surface below. This lead us to conclude that harder isn't better and we needed to look to how other industries dealt with this dissipation.
After plenty of research and R&D turned our sights to materials that could stiffen under force but remain supple when at rest. These super-elastic materials have a reversible elastic response to an applied stress.
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Soft, easy to fit and vibration absorbing when under moderate force (keeps you tracking straight, not pinging off line from roots and rocks).
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Hardens when stressed and superior at absorbing/dissipating force VS more dense materials.