If the derailleurs move freely when the cables aren't attached, then I'd have a look at the routing of the cables: could be a bit tight.
@Scilly.Suffolk started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
If the derailleurs move freely when the cables aren't attached, then I'd have a look at the routing of the cables: could be a bit tight.