La moto cambia radicalmente: motore profondamente rivisto nella parte termica, nel raffreddamento, nell'accensione e nei carburatori, telaio con ampie zone in fibra di carbonio. Cambia anche il nome, si abbandona la mitica sigla AF1 a favore di RS250V. Piloti, il "solito" Reggiani e, appoggiato ad un Team esterno, Pierfrancesco Chili.
The motorcycle was radically changed: the engine was profoundly revised in the heating part, the cooling, the ignition and the carburettors, while the frame had large areas of carbon fibre. The name changed too: the mythical AF1 gave way to the RS250V.

Riders were the "usual" Reggiani and, with an external team, Pierfrancesco Chili.

The new Aprilia soon proved to be an exceptional vehicle: Reggiani was third at Laguna Seca and Jerez, Chili at Misano.

Victory was in the air again and it arrived with Chili on the marvellous track at Assen; he was immediately imitated by Reggiani on the Paul Ricard track.

Massimiliano Biaggi won the European title in the 250cc class.

1991 also brought Aprilia its first victory in the 125cc class: it arrived with Alessandro Gramigni in Czechoslovakia, where he beat Capirossi and Debbia, on the other Aprilia bike, in a flying finish.