This is the 10431st most frequent Russian word.
велосипедах
"Велосипедах" means "bicycles" (prepositional case, plural) in English.
Here, 'велосипедах' is the plural prepositional case of 'велосипед', referring to bicycles as the objects of the preposition 'на'. This usage specifies the location or means of action.
Дети катаются на велосипедах по парку.
Children ride bicycles in the park.
In this sentence, 'велосипедах' is in the plural prepositional case used with 'о', indicating the topic of discussion, referring to 'old bicycles'.
Мы рассказывали о старых велосипедах в музее.
We talked about old bicycles in the museum.
Here, 'велосипедах' again appears in the plural prepositional case with 'на', describing the means of transportation.