This bike originally had two lights mounted, one for the Dynohub, the other was connected to a tire driven bottle generator. The wires to the Dynohub were not connected so I assumed the Dynohub may not be working.
I mounted the rim in the truing stand, connected a multimeter to the Dynohub terminals and gave the rim a spin. Amazingly; after 60 years, and sitting unprotected in the weather the Dyno still produced a current.
Knowing the hub still has some life, I was ready to start disassembly. I removed the hub from the rim and gave it an initial cleaning and degreasing.
|Note the lack of a Spacing Cup (HSD 301) on the left side against the Dyno. Instead, two thick washers were being used. I'm assuming it did not come from the factory this way?|
The internals of the Dynohub are not that different than a normal front hub with the exception of the Armature and Magnet, basically just cones, races, and bearings.
|The Dyno is on the right. The black center portion is the Armature which is stationary, the outer ring is the Magnet which revolves around the Armature producing current.|
This bike appears to have seen many miles, the rear AW hub cones/races were very worn, these are equally bad. The bike did have an old District of Columbia bike registration sticker, that plus the additional lights, and all of the reflective tape suggests a well used DC commuter bike.
Finding replacement parts in the USA for a Dynohub is much more difficult then obtaining parts for a AW rear hub. The bearing races are part of the hub shell and cannot be replaced without replacing the entire shell. The cones are also hard to find, unless you can cannibalized another Dynohub. The caged ball bearings and dust caps are interchangeable with those of the AW rear hub.
|The cones on the left are from the 1953 hub, the cones on the right are from a 1947 hub and will be used as replacements.|
|Original configuration with two washers|
|This is with homemade Spacing Cup|
This is the hub rebuilt with replacement parts, new grease, and shell buffed. I'm measuring the "over-the-locknut-distance" (O.L.D.) to make any final adjustments with spacers, washers, etc. The front fork dropout spacing on Raleigh Sports is approximately 90 mm, so the O.L.D. should be equivalent.
Please share your thoughts and experiences.