ENVE COMPOSITES ALUMINUM ROAD REAR HUB

THE HUB GEOMETRY Wheels are highly complex and often underappreciated in their complexity. First, you have the rim which has to be lightweight and manage rider weight, impacts, airflow, tire pressure, and spoke tension. Then consider that the best rim in the world, if laced to a mediocre hub with compromised spacing and flange geometry, will result in a mediocre wheelset. Nothing on the bike is more complex and dynamic. For the reasons above, we found it necessary to take control of our own destiny by developing a hub that enhances versus diminishes the performance of an ENVE wheelset. So what, does an enhanced ENVE wheelset feel like on the road? Essentially, faster accelerations, and more confident handling when sprinting, standing, or cornering. Here’s how the hub geometry has been refined to out-perform the leading aftermarket hubset, and elevate the performance of complete ENVE wheelsets. The next generation Alloy Road Hub utilizes a paired spoke hole pattern which improves tangency of the spoke angle to the rim by creating what we refer to as a virtual three-cross lacing pattern. The flange diameter itself has been increased from 45mm to 55mm with no weight penalties to maximize torsional stiffness. In the real world this means greater response and efficiency under the most aggressive accelerations.

UNPRECEDENTED RELIABILITY – AXLES, BEARINGS, AND MORE When asked, “What do you value most in a hubset?” the market came back with a resounding response for “reliability.” With that knowledge, we spared no expense in ensuring that the Alloy Road Hub become the gold standard in reliability. The extreme strength and lightweight of the Alloy hub shell allows for the use of robust axles and internals where others are forced with the hard decision of adding weight or compromising long term reliability. The ENVE Alloy Road Hub features a robust 17mm rear axle and a 10mm front axle. The large rear axle diameter reduces flex, improves drive train efficiency, and helps prolong bearing life. On the front hub, a 10mm axle is capped with stainless steel end caps to ensure durability and a long service life. In the same way that a mediocre hub can bring down a world-class rim, a high maintenance or otherwise underperforming bearing can bring down what would otherwise be a best in class hubset. For this reason the Alloy Road Hub comes spec’d with custom premium grade stainless steel bearings. Those familiar with the original ENVE Alloy road hub know that it included ceramic bearings. While ceramic bearings are capable of delivering extremely low rolling resistance and therefore high levels of efficiency, this is primarily achieved by using non-contact bearing seals that eliminate friction between the bearing race and its seal. While fast for the moment, this bearing setup is readily contaminated and if not maintained, bearing performance can be compromised in one ride through harsh weather conditions. It is our opinion that the stainless steel bearing spec’d in the Alloy Road Hub is an upgrade over the first generation’s ceramic bearing both in terms of rolling efficiency and long term reliability. To achieve a balance of long term reliability and efficiency contact bearing seals are used anywhere a bearing is exposed to the elements while non-contact type bearing seals are used on all internal bearing faces. In testing, the stainless steel bearings rolled fast and smooth for literally thousands of miles beyond what the best ceramic bearings were capable of. Additionally, the use of stainless steel means that for cyclists living near the coast, in high humidity, or frequently riding in the rain, your bearings will resist corrosion and look beautiful for years beyond what a traditional bearing is capable of.

PERFECT PRELOAD™ If there was one complaint heard more than any other over the years about hubs it’s that, “My bearings have play in them.” Bearing play is a result of inadequate pre-load on the bearing or sloppy tolerances. Essentially, you have your hub shell, axles, bearings, and it all needs to be compressed together just enough so that there is no play and drag. There are a couple common ways of doing this. The first is a basic stack up, and DT Swiss is an example of this. With this design, one presses everything together and the design’s tolerances deliver the desired performance. This method requires precision machining to ensure everything “stacks up” correctly. It is possible for this design to work, as proven by DT, but with time, any imperfections in the stack up will be magnified by way of accelerated bearing fatigue and diminished performance. The beauty of this design is the simplicity, the down side is bearing life. A more common and forgiving way of managing bearing pre-load is to design the hub with an adjustable pre-load tension feature like a lock ring. This is a proven way of managing bearing pre-load, but is not without its flaws. First, if you need to adjust bearing pre-load, you’re going to need a tool and it’s more often than not a size not readily handy on your multi-tool. If bearing play is permitted to go unattended to, one can permanently damage the hub making it impossible to achieve optimal hub performance without replacing costly components of the hub. The other problem is that of over-tightening your pre-load. If over-tightened, you will certainly not have bearing play, but now you’ve increased drag on the bearings which in turn reduces efficiency and costs valuable energy. Our goal was to solve the problems associated with bearing pre-load and Perfect Preload™ is the solution. Perfect Preload™ promises to maintain optimal preload on the bearings for the service life of the hub. Bearing preload is achieved via a calibrated wave washer and snap ring. The wave washer sits between the bearing and a snap ring installed on the axle. This system produces a consistent and dynamic pre-load setting that eliminates bearing slop and the need for riders to adjust pre-load. Because pre-load is optimized and fixed, bearing performance is maximized, reducing premature bearing wear.

DRIVE MECHANISM When developing a new hub that must meet “best-in-class” performance metrics, it goes without saying that the drive system is figuratively and literally responsible for setting the tone of the entire product. The Alloy Road Hub features a 40t ratchet with 9 degrees of engagement and strikes a fine balance between responsiveness and long term reliability. When ratchet type drive systems with tooth counts greater than 40t were tested, reliability was diminished exponentially. ENVE researched and tested competing drive system designs ranging from pawl to ratchet type systems and ultimately decided upon a ratchet type system for reasons associated with weight savings, efficiency, reliability, and ride tester feedback. Additionally, the ENVE ratchet design minimizes the number of small parts in the system to the drive ratchet, freehub ratchet and a single spring. The ratchet type design delivers maximum weight savings, reliability, and ride testers preferred the ride feel and acoustics over other designs. Finally, the freehub driver body is machined from 7075 aluminum alloy, and hard anodized for durability. The ENVE Alloy Road Hub is compatible with Shimano, SRAM, and Campagnolo drivetrains by simply exchanging the freehub body – no re-dish is required.