Upgraded “Nano-Velcro” carbon rims resist knocks in MTB races
Few things punish bike wheels harder than world championship-level downhill mountain biking races, which is why Frenchman Nawa Technologies has signed up with a top-level downhill team to prove the strength of its fiber. carbon reinforced with nanotubes.
We have covered Nawa extensively in the past. The specialty of this French company is the production of vertically aligned carbon nanotubes (VACNT), which it claims to be able to make at low cost and on a large scale. These nanotubes could enable impressive advances in battery technology – for example, when used in electrodes, Nawa says they could triple the density of lithium batteries and unlock other battery chemistries that still deliver performance. higher.
But they can also be used as a kind of “nano-velcro,” to strengthen the bond between layers of laminates like carbon fiber, a process the company called Nawastitch after they acquired it as part of a contract. acquisition of Massachusetts-based N12 Technologies. Last year.
Normally, carbon fiber sheets are layered, with their fibers aligned in different directions, and glued together with epoxy. When the finished part is stressed under load, it can warp, and during those warps, Nawa says the epoxy can be a weak spot, deteriorating until the part delaminates and sags.
The Nawastitch process adds VACNTs to the epoxy layers, adding a velcro type handle that increases the shear strength between the layers by two orders of magnitude and impact resistance by an order of magnitude. Impacts, says Nawa, cause 50% less damage and delamination just doesn’t occur.
Clearly this would come in handy in MTB wheels, especially the way professional racing teams hit them against rocks, roots, and ruts. Nawa has announced a partnership with the Santa Cruz Syndicate, one of the top performing teams on the UCI World Cup and World Championship circuit, in which Santa Cruz will officially use the Nawastitch material in its carbon racing wheels from Reserve brand.
We’re saying it officially, because Santa Cruz has been using these nanotube-reinforced carbon rims since 2018. “Downhill, the wheels take hard and repeated impacts with rocks and roots,” says Santa Cruz senior composite engineer Nic McCrae. “Failures happen when the tire hits bottom and the rim bead cracks. NAWAStitch made the wheels a lot stronger, we think by increasing the buckling resistance of the inside surface of the rims during these high compressions. We had a lot fewer wheel failures because Thanks to a combination of our own profile design, precise wheel construction and the introduction of NAWAStitch, our Reserve wheels are without a doubt the strongest rims on the circuit. .
While neither party has given figures on the exact performance of these rims, Nawa says the material “has the potential to significantly reduce by 80% the number of wheel failures encountered by the team during a season of competition “.
For now, these Reserve wheels are reserved for the racing team, but Nawa says bringing them to market as a mass product is a “long-term goal.”
Source: Nawa Technologies