  |
Fortunately the gentlemen at that time still allowed themselves the luxury of coming regularly together, and if opportunity presented itself, one by pastime took a photo of the other’s pastime. But even so we managed to collect only about forty photos on paleocyclists from Michaux’s boneshakers through the tricycles and quadracycles to the penny-farthings, and this number already includes the dwarf version of the tricycle which has stalled in the phylogeny, the children’s tricycle. If you know about any more photos of velocipedists, send them for our collection.
Velocipede factory in the USA
Requiescat in pace
Come with us to…
Atlantis
Bestiary
Bohemia+Prague
Books, exhibitions, music, film
Caucasus
Cemeteries
Crimea
Get to know the
Images of the East
Lwów/Lemberg
Mallorca
Message on the wall
The Museum of Propaganda
Odessa
Paper Museum
Persian letters
The Jewish heritage
3 comentarios:
j'adore la bicyclette, je suis impressionnée par la richesse d'informations et de photographies que vous rassemblez et que vous partagez ! merci et bonne journée à vous !
Merci, Dominique. Quelques autres articles sur les bicyclettes suivran, donc revenez bientôt!
Does a bicycle need a rider to be stable? A curious paper entitled "A bicycle can be self-stable without gyroscopic or caster effects" recently appeared in the journal Science. The abtract states "A riderless bicycle can automatically steer itself so as to recover from falls. The common view is that this self-steering is caused by gyroscopic precession of the front wheel, or by the wheel contact trailing like a caster behind the steer axis. We show that neither effect is necessary for self-stability. Using linearized stability calculations as a guide, we built a bicycle with extra counter-rotating wheels (canceling the wheel spin angular momentum) and with its front-wheel ground-contact forward of the steer axis (making the trailing distance negative). When laterally disturbed from rolling straight this bicycle automatically recovers to upright travel. Our results show that various design variables, like the front mass location and the steer axis tilt, contribute to stability in complex interacting ways". The full paper is behind a paywall, but a pre-print may be found here. Some of the bicycles in the post look like they would benefit from "linearized stability calculations".
Publicar un comentario