The new Aero Mo-Mag system advances wheel technology still further.
Most bicycle wheel rims have a spoke hole on their inner surface where the nipple locates, and an aligned hole in the rim bed, which helps position and tighten the nipple when building the wheel. It’s a mechanically sound practice, but it does have its compromises.
A rim with more holes in it will be weaker and more prone to flex, can allow water in, and will need a rim tape for clincher or tubeless use. Campagnolo’s innovative Mo-Mag system only requires rims to have holes in their inner surface for the nipples, leaving the rim bed intact, with no weakening holes.
Mo-Mag spoke nipples are inserted in to the rim through the valve hole, and pulled in to place with a magnet, before screwing on to the spoke.
It creates a stronger, more durable and more reactive wheel, with external nipples.
The new Aero Mo-Mag system advances wheel technology still further, with completely internal, hidden nipples, which have benefits beyond their obvious aerodynamic advantage. Each rim and hub combination has fibreglass-reinforced polymer nipple seats, which are specific to that particular wheel build, because they align each spoke and nipple perfectly with the hub, reducing real-world stress on each component.
Campagnolo mould the spoke and valve holes into their rims, so no carbon fibres are cut by drilling them afterwards.
Every spoke hole on the Bora Ultra WTO rims has an internal nipple seat, wrapped into the rim’s carbon layup at the moulding stage, which is perfectly aligned to the intended hub. A magnet is then used to position the new internal nipple within the nipple seat, where it locks into place.
The internal nipple repositions the nipple guide chamber, and the first screw threads well inside the rim, allowing the rim, rather than the vulnerable initial spoke threads, to absorb the flexing and bending forces generated by cycling.
This hugely reduces the risk of spoke breakages caused by stresses that are usually concentrated in this area.
Each hidden nipple has a polymer insert, which locks the tip of the spoke in place, much like a Nyloc nut, to prevent it loosening. Initial wheel truing and subsequent spoke tension adjustment is carried out in the usual way, but using the supplied proprietary, hollow-tipped, Torx T25 tool, which inserts into the recess around the spoke to engage the inner face of the nipple.
The Torx tool is turned by a regular wrench, and an aero spoke holder is provided to ensure correct spoke alignment. The presence of the different materials used to build wheels, and humidity, can result in galvanic corrosion.
An aluminium nipple, stainless steel spoke, and exposed carbon fibres in contact with each other can result in the aluminium component oxidising.
The Aero Mo-Mag system insulates the nipple from the rim, vastly reducing the chances of this occurring.
Aero Mo-Mag creates cleaner-looking, more aerodynamic, mechanically durable, easily maintainable wheels that leave no excuses.