I started to clean the MTB after yesterday's ride and noticed grittiness in the wheels

So after a quick trip to
Halfords for some of their lovely citrus degreaser both hubs got disected, stripped of all the old manky grease, cleaned and rebuilt with creamy new grease

... also in for a degrease and clean were both mechs, crankset, cassette and chain.
Then I remembered I have another set of wheels for this bike

, so they got the same treatment too
All that's left to do is tidy up and open another bottle
