MIPS’ latest rotational impact protection technology, Integra Split, is soon(ish) to be available on an open-face helmet for the very first time. That helmet is the Fox Speedframe RS, a new top-of-the-range variation on the brand’s best-selling mountain bike helmet.
Fox Speedframe RS with MIPS Integra Split
It’s not the first time we’ve seen Fox implement MIPS Integra Split. Indeed, it actually debuted on the DH-certified Fox Proframe RS last Fall. However, the Fox Speedframe RS will be the very first half shell helmet to benefit from the technology. And, Fox will have exclusive use of it for at least one year post launch.
So, what is MIPS Integra Split?
It is very similar to MIPS Spherical, in that it is essentially a two-layer system wherein two distinct layers of EPS are separated by the MIPS liner that connects the two via small elastomers that MIPS refer to as “woofers”, owing to them having a shape similar to that of a sub-woofer. The woofers allow for 10-15mm of free movement between the two layers, movement that is critical to managing rotational forces experienced by a rider during an impact.
Also, the two EPS layers are of differing densities; the inner layer is designed to manage energy involved in low speed impacts, while the top layer that is in-molded into the helmet’s outer shell is composed of a higher density EPS that is designed to absorb energy involved in higher speed impacts. Clearly, that is a very simplistic way of describing it, as it all works in concert, but that is the basic gist.
How MIPS Integra Split differs to MIPS Spherical is very simple; the inner layer of EPS is actually split into two intercalating plates that can move independently to one another. This can be clearly seen on the model we saw at Eurobike a couple weeks back.
The movement between the two inner halves is quite subtle, but we are told that it allows helmet manufacturers to shape the liner around the headform to produce a better, more consistent fit, with a more consistent amount of EPS foam between the skull and the outer shell.
Of course, there’s a lot more to the Fox Speedframe RS than its MIPS Integra Split.
Other updates include use of a BOA Fit System at the cradle, a new easy-adjust visor that has a single, centrally-positioned anchor point to avoid accidental crooked positioning, as well as the addition of sunglasses-stowage under the visor. A grippy runner will be placed where the arms slide in to add a bit of friction for a secure hold.
The helmet is finished off with Fidlock’s magnetic closure for the chin strap, with an Ionic+ comfort liner that has been treated to impeded microbe growth, and thus the production of sweat-associated faust.
Pricing & Availability
The Fox Speedframe RS isn’t due to hit stores until April 2024, and pricing is still TBC.