I’ve just replaced all the cables on my cx bike.

when I’ve tried to sort the indexing out it wont shift down into the smallest cog on the cassette.

when its on the biggest cog I have to double click for it to shift down only once

what going on guys?

Assuming that nothing else has changed (shifters, fiddling with the limit screws on the mech etc.) I’d try undoing the cable retention bolt on the mech. and clicking the shifter into the high gear position and reattaching the cable; you might have accidently clicked the shifter between fitting the cable and bolting it to the mech.

What he said.

what she said !

You have done it wrong 😉

http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

Bottom of the page

Cables too tight.

indexing gears