Disc wheels are now available for a road bike. Reinforced hubs, multiple tightening system, type of fixing of the discs, the diameter of the rotors, the cyclist is in front of multiple choices of purchase with new data to take into account.
Disc wheel with aluminum or carbon rim
Aluminum or carbon, both materials exist. Thus the choice of material is always chosen on the same principle as for the wheels with brake pads, depending on:
- Your budget
- Your weight
- Your level
- The destination: training or competition
The type of terrain on which you operate (linked with the profile of the rims)
Rims for disc brakes: What changes!
What changes here is the lack of a braking surface dedicated to the pads because the rims are intended for use for disc braking. A priori, the stress applied at this level is no longer (warming up). This can reduce the thickness of the carbon layers or the size of the profile of a rim (depending on the marks). This is a point of detail (and a few micrograms), certainly, but the gain of a few grams around the rim plays a major role in the behavior of moving wheels at Walmart Auto Centers.
The overall design for a high-demand disc wheel
It is especially the hub/spoke/ rim connection that will be put to the test. Disc wheels are much more stressed in terms of torque transmission because braking is much more violent than acceleration. To be convinced of this it is enough to count the number of seconds that one puts to go from 50km / h until the stop while braking supported and to compare that with the time that one puts to pass of the stop at 50km / h pedaling!
The rear wheel: This one is requested at the level of the transmission on the right and the level of the braking on the left.
The front-wheel: It is the front wheel which is the most stressed (in the transmission of torque) since the majority of the braking is done in front (because of the transfer of mass).
The spokes mounted on the disc wheels are the same. It’s rarely the weak point of a wheel. On the other hand the modifications at the level of the arrangement (crossing) and the number of spokes (more important in the disc). There may also be some adjustments at the rim (but mainly in terms of drilling angles to fit the specific rack that is crossed).
- The system for fixing discs (rotors)
- The disc wheel manufacturers must choose as to the hub-related disc fixing system. This is the design method for attaching the disc (also called rotor) to the hub of the wheel. Two systems exist to date:
- The 6-hole or international standard system used by the majority of market players
- The Center Lock created and used by Shimano.
- The 6-hole system is what gives the best geometry at the front hubs.