English to Romanian Tech/Engineering Mechanics / Mech Engineering

Context:

But the lack of a derailleur on this single-speed
road steed means that there’s no gear system to
gunk up. Its maintenance-free carbon-composite belt
(instead of a steel chain) makes it lighter, quieter, and
smoother as well.

Definitii: http://www.google.ro/search?hl=ro&q=define:derailleur&btnG=C...

Imagini: http://images.google.ro/images?hl=ro&q=derailleur&um=1&ie=UT...

Multumesc!