Possibly one of the biggest innovations in rim engineering in recent years

Wheels are the first point of contact between you and your bike, and the trail you’re riding on. And while wheel sizes and standards continue to develop significantly year on year, often to both the rider and the industry’s dismay, very little innovation has been seen in the compliancy and responsiveness of the wheel as this first, most important contact and conductor.

What we have seen in recent years is that bike suspension is continuously evolving and adapting to compensate for stiffer frames and more rigid, deeper profile carbon fiber rims. This overall stiffer rig is being softened, or counter-acted by both bike suspension, and tire design – not to mention the ever lower and lower tire pressures riders are running. Rider position (wider, lower, more forward) is also being impacted directly by the bike frame and cockpit geometries which is constantly aiming for a better riding feel. So surely it is overdue time to re-examine how the engineering of the wheel can become an active contributor to the efficiency of the overall set up.

Spank Industries has done just this. With 15 years of dedicated know-how in rim and wheel design and manufacturing, and with over 180 rim profiles successfully brought to market by founder and chief of design Gavin Michael Vos, for both Spank Industries and other top 10 rim and wheel brands, Spank Industries releases at the 2018 Eurobike Show, what is probably one of the biggest innovations in rim and wheel development in recent years: The new SPANK SPIKE 350 Vibrocore™ for Downhill and Free ride and the SPANK OOZY 350 for Trail, All Mountain and Enduro.

KEY ENGINEERING FEATURES & BENEFITS

1. “Wide and low profile adds significant radial compliancy.”

Against all current market trends, the profile of both the new rims is very low with a 17mm sectional profile height and 35mm outer width, 30.5mm inner width. In laboratory testing, this lower and wider profile is showing around 30% more radial compliancy compared to a more conventional alloy rim of approximately 34.5mm outer width, 30mm inner width and 22mm sectional height.

This added radial compliancy dramatically reduces deflection of the wheel when it hits abrupt obstacles, rutted corners and roots for example. Instead of “jumping” off the intended line, the wheels are able to flex radially and move with the rider’s momentum and the bike’s direction, rather than fight against it. This is often referred to as the wheels “tracking” ability. This forgiving responsiveness will allow riders to start increasing tire pressure again as the wheel will itself contribute towards better traction, improving acceleration and rolling speed, and reducing tire rebound.

2. “New profile increases lateral stiffness and torsional strength.”

The shallow to wide profile ratio adds lateral stiffness and torsional strength. So while the radial compliancy allows for more flex, the enhanced lateral stiffness keeps the wheel true. Likewise, torsional strength is enhanced, significantly reducing the likelihood of the wheel buckling, or taco’ing.

With an internal width of 30.5mm, the rim is extremely versatile, fitting tires from 2.0" to 2.6" perfectly, and even allowing + size tire use, without negative squaring off of tire profiles. This means tires act predictably, and cornering traction is more consistent.

The above features and benefits are relevant to both the OOZY 350 as well as the SPIKE 350 Vibrocore™ models being launched. Unique to the SPIKE 350 however, is Spank Industries’ Vibrocore™ damping system.

The SPANK OOZY 350 comes without the Vibrocore™ foam core, which makes it ideal for Trail, All Mountain and Enduro bikes, looking for a wide profile (and improved comfort and traction), without a weight penalty.

3. “Vibrocore™ inner well maximizes torsional strength in a light weight, vibration damping core.”

Spank’s Vibrocore™ has been put to the test over the past three years by pro-riders, consumers, reviewers and lab testing alike. Despite skepticism about how much a ‘foam filled bar’ can really improve rider comfort, the results have been undeniably notable, and have been backed by the data and lab results.

Now Spank has applied the same principles to the rim. With the significantly heightened radial compliancy of the new SPANK 350 rim, a direct result of the ratio between the incredibly low sectional profile height and the 35mm width, the engineering objective was first and foremost to ensure strength, torsional and lateral, for the higher demands of DH Race and free ride.

While adding just 40g to the overall weight of the rim, Vibrocore™ foam core increases torsional strength and increases the overall fatigue life of the rim, meaning high durability at a remarkably low weight. In fact, Vibrocore facilitates modern rim designs with thinner wall thicknesses in some areas, without any negative effect on strength and resilience. While acting in a similar fashion to the soft tissue inside human bones – which offers inner wall strength by applying an expansive internal load, Vibrocore™ will also dampen certain vibration frequencies, ultimately meaning less vibration for the fork to deal with, and less to the rider.

Data on the frequencies affected by applying Vibrocore™ to Spank’s rims will be available in due course.

Initial testing of both new rims with Commencal Riding Addiction and other SPANK athletes have proven drastically improved ride characteristics and performance.

Both the SPIKE 350 Vibrocore™ and the Oozy 350 will be available as rims in 27.5” and 29”, with a suggested MSRP of USD/EUR 99.90 for the Oozy 350 and USD/EUR 129.00 for the SPIKE 350 Vibrocore™. They will also be available as wheelsets at suggested MSRP of 649.00 for the OOZY 350, and 699.00 for the SPIKE 350 Vibrocore™.

RIDER TESTING & REVIEW

SPANK Industries works closely with riders in the development of their new products and technologies.

For the 350 rim and wheel R&D, they have worked with Rob J (Rob Heran) focusing on testing the OOZY 350 wheels, but also the SPIKE 350 Vibrocore™, while the Commencal Riding Addiction DH Team (Myriam Nicole, Remi Thirion, George Brannigan, Thibaut Ruffin and Gaetan Ruffin) have been testing the SPIKE 350 Vibrocore™ wheels exclusively.

Free rider Ethan Nell will also be putting a set of 26” SPIKE 350 Vibrocore™ wheels to the test in his training and competition run for the 2018 Red Bull Rampage event in October this year.