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It took Alchemy and Wheels Mfg designers a couple of years to make the ORC rear hub real and available. Designed to meet the most important criterions on a hub: stiffness, reliability, low bearing resistance and weight, we obviously wanted to offer this new jowel through our Absolute full custom wheels. What makes this visually classic hub so special? In a first time, the geometry is not so common, this hub has been thought with wheel lateral and torsionnal stiffness in mind. Indeed, the large diameter shell makes this hub torsionnaly stiff. Additionnaly, the flanges are pretty tall, making the spokes very tangent to the hub for a very torque resistant wheel. These flanges are oriented toward the bracing angle of the spoking, for an easier spokes seating.
Then, the right side flange spacing is optimized quite a lot: it takes place close to 20mm from the wheel center contrary to a normal hub where this distance hardly reaches 17mm. This drive side width, coupled to a cleverly placed non drive side flange turns into very stable, very balanced rear wheels, both in term of spoke tension and lateral stiffness.
As comparizon, with similar wheel design, this hub increases the non rive side spoke tension from 5 to 10% compared to a standard hub. This tension rise increases the wheel reliability. 
In a second time, the internals rely on an unprecedented very strong and beefed up design. The 17 to 20mm oversized alloy axle is matched to strong section bearings - 6903, 6804 in the shell and 6803 in the freewheel - to stiffen significantly the system. Such bearings can handle way more load than the 6801, 6802, 6901, 6902 series generally used in hubs. Their high resilience enhance life and reliability of the hub. Last but not least, the freewheel is pressed into the shell in a very uncommon way. Generally the freewheel is fixed to the body through the torque transfer parts: ratchet, pawls, sometimes through an internal bearing too. In the case of the ORC, the freewheel not only anchors in the shell through these two links, but also through an extra bearing larger than the rotor. This super large 6707 bearing including the whole freewheel brings important benefits: it prevents any flexion, it stiffens the system and improves lifetime.  " I wanted a hub that is reasonably light. But, I did not want to sacrifice performance to get it. Thus, my hub is not as light as some other superlight hubs (but still lighter than most), but I believe that it offers performance gains that more than offset the weight difference." adds Jeremy Parfitt the designer.
This hub hits the scale with 220g.
Every single design effort makes the ORC hub compatible with any rider. Clearly, like the ELF front hub coming from the same manufacturer, there is no weight limit on this rear hub. The spoking will need to be adapted to the rider weight. |
