Eurobike 2017: Foam-Filled Rims From Spank Industries

It was Eurobike 2015 when we last spoke to Spank and found out a little about their Vibrocore handlebars. In short: No, it’s not just expanding bulders foam, yes it does attenuate vibration, and the biggest surprise: it dramatically increases the fatigue life of the handlebars. Unlike this thing, Spank actually had lab testing and data to back up their claims of vibration reduction.

For 2017, they’ve returned with a new product bearing the Vibrocore moniker: rims. That’s right, foam filled rims. Just like with the bars, Spank have made similar assertions for Vibrocore rims: attenuated vibrations, and higher fatigue life. They also said an unexpected effect of the Vibrocore rim was a quieter ride: without a hollow rim to bounce off, apparently sound that would normally echo around inside the tyres is significantly deadened.

This is the new foam-filled, Vibrocore rim from Spank.

Obviously they’ve left the spoke holes unobstructed.

These also have a completely new rim profile – they haven’t just taken an existing rim and filled it with foam, but taken what they learned with handlebars and designed the rim extrusion to work with the filling. In a move that bucks current industry trends, they’re also saying their 35mm outer width rim profile is designed to allow riders to move back towards higher tyre pressures while maintaining traction. The foam adds 40g per rim, and they also said one of the hardest problems they had to solve during prototyping was how to inject a rim full of it cleanly and efficiently without it going everywhere. You can shove the foam in any hole, but there are 65 others for it to shoot back out of!

Here’s a cutaway.

As you can see, the rim has a very low profile, at just 17mm vertically from the spoke holes to the top of the bead lips, compared to a 35mm outer width. The foam apparently reinforces it enough that this can greatly increase wheel compliance and comfort without compromising strength.

Another plus of this is never, ever again having to spend fifteen minutes trying to shake a dropped spoke nipple out of a rim.

The rims have been ridden by the Spank Team, Commencal, and been put through their paces in the SGS test lab. At present, Spank are only planning 27.5″ and 29″ versions of the rim, no 26″ for now. Initially, the only wheelset it’ll be included with is their Spike DH wheelset, with a 150mm rear hub, but rims will be sold separately too. A non-Vibrocore version of the rim will be on their trail wheelsets and also available separately.

You can read Spank’s own pitch for Vibrocore and how it works here.

Vibrocore rims will be available as part of complete wheelsets, or by themselves.

The only wheelset with the Vibrocore rims is Spank’s Spike DH wheels.

You won’t get confused about which rims have the foam in.

Radially compliant: that’s me after a few drinks.

David Hayward

David started mountain biking in the 90’s, by which he means “Ineptly jumping a Saracen Kili Racer off anything available in a nearby industrial estate”. After growing up and living in some extremely flat places, David moved to Yorkshire specifically for the mountain biking. This felt like a horrible mistake at first, because the hills are so steep, but you get used to them pretty quickly. Previously, David trifled with road and BMX, but mountain bikes always won. He’s most at peace battering down a rough trail, quietly fixing everything that does to a bike, or trying to figure out if that one click of compression damping has made things marginally better or worse. The inept jumping continues to this day.