Bicycle are getting very difficult to understand as more and more specialisation appear when we start to search for the right bike.
One of the category is called "Audax".
AUDAX is a form of riding style and the so-called bicycle or frame are more destined for this use.
Originally AUDAX is Latin for "Courageous" and was first used in 1904
in France where a type of event was developed. The events have a little
bit evolued since and mainly after 1921by Audax club Parisien and are
still now similar.
It is Randonnee (touring) at Free Pace over 300km, 400km, 600km and
1000km (the biggest and most notorious is the Paris-Brest-Paris)
Riders ride at their own pace as long as maintened an overall average
speed of 15km/h for up to 600kms distances and 13.3km/h for
1000km and over.
The event name are called "Brevet" and you will find in several place internationally.
A bike called "Audax" is mainly intended for this type of use.
The frame is similar to a road frame, often of 700C wheels size but can
be of 650B or 26", featuring braze on for mounting mudguards and racks
as well as dynamo light.
The frame might accept larger tire section than a road race frame.
Head and seat angle might be a more relaxed to be more comfortable.