I have a Planet X road bike with SRAM Red rear mech running on an SRAM block with SRAM chain.
It has been great until recently when - intermittently - it will start making a noise not dissimilar to that when you are not quite in the gear, but loader and not constant (difficult to explain).
If I pedal backwards, it stops - for a while anyway.
If I change gear, sometimes it stops sometimes not.
Has anyone got any ideas what can be causing this?
The rear mech, chain and sprocket look lined up to me.