Hub dynamos became that common in the meantime, that explaining their advantages over other ways of generating energy on a bike is unnecessary. Even Roadracer and Mountainbiker take to those lighter, more powerful lighting systems and put aside the environmentally unfriendly and high-maintanance (rechargeable) battery lights.
But cheap dynamos make no sense: surplus weight and power consumption while running idle. And in case of failure complex and expensive repair. Therefore, the higher the demand in use, the higher the requirements of quality.
The hub dynamo: SONdelux
The small light one.
The SONdelux is the first hub dynamo whos generator is developed to meet the requirements of modern LED headlights. Since Decembre 2009 the SONdelxe in combination with the Edelux got approved according to German StVZO for tire sizes 16"-28".
A LED is - contrary to a halogen bulb - highly effective, even if run below the nominal power. Hence it is not necessary to built the generator to reach full output at low speed. Because of that the SONdelux could be smaller and lighter tha a dynamo for halogen headlights. Compared to the SON 28 power consumption lowers about 30-35 %, yet is is as robust and well built as the SON 28.
The rim: Mavic Open Pro (black)
The reference road rim.
Open Pro C is the latest version of Mavic "Open" rims, and as such is the most advanced evolution. Optimized up to the limit of material potential, Open Pro C is probably one of the best road aluminium clincher rims available.
Maxtal - Exclusive to Mavic. An aluminum alloy that is 30% more resistant than a 6106 alloy for lighter and spicier rims.
SUP (Soudé Usiné Process) - A welded and milled rim joint which is extremely strong, eliminates shuddering when braking and offers superior wheel balance.
UB Control (Usiné Brut Control) - The braking surfaces are milled to improve braking friction and eliminate shuddering.
Weight: 435 g
The spokes / nipples: Sapim Race / Polyax
The Sapim Race is a strong and light butted spoke for a variety of purposes.
Sapim butted spokes have two major benefits: they are lighter and stronger than plain gauge spokes! Technological advances using cold forging (SAPIM Forging Technology) 'stretch' the spoke, retaining the linear molecular structure of the material and thereby increasing the spoke strength at the middle section by at least 48%.
The Sapim Race comes in a diameter of 2 mm at the ends and 1,8 mm in the middle section.
Brass nipples are very strong and offer great longevity. Standard brass nipples suit all purposes. Spoke thread Ø 2,0 mm. Nickel-plated, square machined. Suited for machine assisted and manual wheel building. Weight per nipple 12mm 0.97 g.
Wheels with SON hub dynamo
The front wheels are all hand built, spanned and centered. This and a high spoke tension grant a high stability and longevity of the wheel. SON always uses Spaim Race stainless steel spokes and brass nipples for 26" and 28" wheels. The double butted spokes are more flexible than continuous ones, therefore load is dispersed over more proximate spokes. The spokes are triple-crosse and forced off several times during spanning.
The flanges outline fits the spokes arch, so they snuggle perfectly together without building up unnecessary tension. Hence it can be resigned to postform or to add brass washers to the head of the spokes.
As a matter of principle, the heavier the rim, the more resilient the wheel.
A stable rim, evenly tensioned spokes of high quality and an experienced hand in building add to the resiliance of a wheel, not necessarily a large number of spokes.
