[2] He started playing the guitar when he was a teenager interpreting the groups he liked, such as "Extremoduro, Barricada, Kiko Veneno, Pepe Risi, Santiago Auseron or Sabino Méndez".

He also was influenced by the English Rock With groups like The Rolling Stones, The Beatles, Marc Bolan and The New York Dolls.

With collaborations from other artists such as Alejo Estivel, Miguel Rios, Andrés Calamaro or Ariel Rot, Ruben has also collaborated with Joaquín Sabina, for who he wrote the song "Embustera" which was included in the CD "Vinagre y rosas" and "Poncho K" (“el ultimo sol") and "Ivan Ferreiro"(SPNB).

In this times he also was the producer of the discs "Pequeño Salvaje"(group owned by the actor Fede Celada and the ex-singer of Buenas Noches Rose, Jordi Skywalker).

After the separation of Pereza (although Leiva and Ruben still have a good relationship) and a period of charm, by the end of 2011 he starts working on a new band, with the aim of composing his first solo album, which was released in the spring of 2012 with the name "Lo que más".