A hub dynamo is more efficient, and don't cause sidewall wear as the bottle dynamos do. ANd they give power to bike lights w/o having to bother with batteries.
No. Bicycles with external gears have chain-and-sprocket gears. Bicycles with internally geared hubs have both a chain-and-sprocket gear and spur gears (usually in a planetary configuration) inside the rear hub. Then there are the rather rare shaft-drive bicycles, which use bevel gears. And maybe an internally geared hub as well. Then there's the occasional belt drive bike of course. And one or two CVT designs.
Usually called a coaster brake. It's built into the rear hub and can't be added later - unless you replace the whole hub.
Dynamos F.C. was created in 1963.
Invicta Dynamos was created in 1997.
Houston Dynamos ended in 1992.
4 dynamos were installed on the Titanic.
Tralee Dynamos F.C. was created in 1961.
Bicycles are STILL used.
London
There is no specific collective noun for bicycles, in which case a noun suitable for the situation is used, for example a rack of bicycles, a row of bicycles, a standof bicycles, etc.
Dynamos F.C. - South Africa - was created in 1997.
Sell used bicycles.