I just gave my bike a going over with new bearing cages in the BB and a new chain. After putting everything back on I indexed the gears - finally getting the hang of the front but first time indexing the rear derailleur. It all felt fine on the stand, but when I go uphill with the rear gears on the lowest cog (6), when the pressure is on the pedals I get a weird jumping, clunking thing keep happening.
Now I was told this could be because my rear cassette is worn, but I've had a close look and done the brake-on-pedals-pushed test, no play on the chain on any cog, looks fine to me, how does this look to you : The mech doesn't look bent, either. Is it just that I need to get my indexing in better form, and need to perfect the cable tension, or are there other causes for this (like maybe wear on the drive cogs - do they look like they need replacing below?)?