OOHBAH
The most important features of any rim are rigidity and weight. Rigidity or stiffness means more of your energy is transferred into drive force, (rather than flex) and acceleration/cornering/braking performance is improved. Reducing rolling weight in your wheels, more so than any other part on your bike, can dramatically reduce the energy needed to propel it forward.
Take a look at a cross section of any given rim on the market. You’ll see that both the outer and inner walls are concave. Now check out a SPANK rim. Their unique patented Oohbah™profile with inverted tube well, approaches a toroidal shape, which has the lowest mass and highest stiffness on all planes. This increases rigidity immensely compared with conventional rim designs. The combination of a concave outer wall with a convex inner tube well, results in the addition of a new, never before seen “hoop strength” in the sectional profile, which lends massive strength and stiffness to the rim as a whole, and places the center of inertia in the optimum position nearer the center of the profile.
Furthermore the “wave” shape of the Oohbah inner tube well acts like corrugated steel roofing to add strength and support to the vertical rim flange walls and prevent buckling. Normal straight or curved tube wells must be much thicker to offer the same support. The increased strength and rigidity offered by our Oohbah™profile affords us the opportunity to optimize wall thicknesses and material transitions, drastically reducing weight…AND…allows us to offer rims with greater widths, at much lower weights than our competitors. Wider rims mean stiffer wheels and more tire spread, leading to greater traction and improved comfort.
Content courtesy of Spank
Update 16 April 2018
I’ve been building wheels using Spank rims since I built a set for myself in 2015. Since then I have built many sets of wheels with various models of Spank rims and they have all come together very nicely and I’ve not had any comebacks. I currently ride the Spank Oozy Trail 345 rims laced to Hope Pro4 hubs and honestly, couldn’t be happier. Look out for a future article where I build and review Spank’s new Vibrocore rims.
These are my personal wheels – I simply love them 🙂
