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: SON 28
The SON 28 is a hub dynamo, approved for wheel sizes from 16" up to 29". The nominal output is reached at app. 16 km/h with a 28" wheel. Thereby it is recommended when a lot of light is needed at low speed, or auxiliary devices shall be run or their batteries shall be recharged.
The new SON 28 standard version (non-disc) received optimized flange- and bearing spacing. Disc versions are available as IS 6-bolt and centerlock. In contrary to the classical SON 28, the power loss could be reduced at app. 15% and the weight got reduced to 440 g.
The rim: DT Swiss R460
The jack-of-all trades of road rims: light, wide and with an ideal price/performance ratio. The R 460 works perfectly with wide tires and will deliver many unforgettable rides on the road thanks to its reliability. Furthermore it is tubeless ready.
Sleeved
A precise sleeve connects the profile. This guarantees optimum resistance against all occurring loads. Sleeve jointing is the best alternative to SBWT® welded rims.
The DT Swiss Wear Control® shows the extent of rim wear. It is compliant to the European standard.
Tubeless compatible rims can be converted for tubeless use with the help of a tubeless kit.
Weight: 450 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.
