There are three models of SON hub – theSON 28 (above) is perfect for full-sized wheels with any light, the 28 Classic(below) is similar but in a larger and cheaper casing, and the Delux (right) is optimised for low drag with LED lights.
Why fit a hub dynamo? One word – reliability. A hub dynamo is always there, completely sealed from the elements, and always works – no matter how much mud or water there is about. If there’s one thing you really want from your lights in the middle of a wet winter commute, it’s reliable lighting.
Wilfried Schmidt only makes dynamo lighting – he’s a bit obsessive about it 😉 The SON dynamos are the best ones made anywhere – light, able to provide lots of power if asked, low drag, and above all very reliable.
An example of attention to detail on the SON…: The SON is a very high precision hub – in fact, it is airtight. Because it it airtight, the air inside expands and contracts with changes in temperature, and SON found that in some circumstances this could suck water in past the seals on the bearings. To solve this, they fitted an internal bellows connected by a tiny tube to the outside air – the bellows expand and contract to compensate for changes in temperature, but keeps the hub completely sealed against the elements. That’s how good SON are at attention to detail! See also the SON Edelux front light…