SON 28 6-Bolt Disc SL Dynamo Front Hub - Silver Anodised

The electrical connection to a hub dynamo meets many requirements. It should be convenient to use, easy to fit to the cable, robust and reliable. Moreover, it should be inconspicuous yet elegant. Whereas competitive products meet the first two criteria, the blade terminals used on standard SON are far more robust but not that easy to handle.

Without doubt the most elegant way is to avoid the connectors altogether by using the areas where hub and fork touch, i.e. the contact face. The mating process is done automatically by installing the wheel, the contact pressure of the skewer protects the contacts from corrosion.

In 2009, Schmidt Maschinenbau introduced a self-connecting system where the phase contact occurs in an insulated contact plate placed on the right drop-out and the ground contact lies on the bare left drop-out (aluminium or stainless steel). The phase cable usually runs inside the fork blade of the fork crown, where it meets up with the ground cable.

This system is called SL (German "steckerlos" i.e. without connectors).

The benefits are evident:
- Most convenient for mounting and dismounting wheels
- Elegant due to invisible cables and connectors
- Maximum reliability of operation

The only drawback: The fork must be specially built for SL. Schmidt decided to do without retrofitting in favour of maximum robustness. However, a standard front-wheel hub may be fitted into an SL-fork. Please make sure your fork is compatible before commiting to buy an SL hub.