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It happened the last time I washed the bike. It's happened again this time. The rear derailleur won't shift the chain up even though I was careful about not pushing the cog wheel up or down. Last time the bike mechanic sorted out stuff but I can't do this every time I wash the bike! What has happened and how do I re-adjust the derailleur after every wash?

  • You should definitely not need to adjust the rear derailleur after a wash. Suggest you ask a bike friend to show you how they clean their/your bike- as I am afraid it sounds like you are doing something wrong. – AliGibbs Nov 26 '15 at 9:22
  • what are you using to wash the bike? If the answer is pressure washer then stop doing that. you shouldn't need anything more than a mist setting from your hose nozzle to get the soap off. If you need to get dirt off certain areas scrub with your hands so you can ensure you are delicate around the areas that require it. – Kibbee Nov 26 '15 at 13:40
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    @Kibbee I would say that "If the answer is pressure washer" then you should probably rebuild your bike, as there is going to be water where the should be oil. – Aron Nov 27 '15 at 3:13
  • About three-fourths of "won't shift" problems are due to the cable. Maybe it just needs lubing, maybe it needs replacing. – Daniel R Hicks Nov 28 '15 at 14:36
  • (And why would anyone ever wash a bike anyway??) – Daniel R Hicks Nov 28 '15 at 14:37
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This is an interesting one - if we treat it as a derailleur that won't move right, perhaps work backward to the cause, instead of working forward from "where could water go to cause this?"

Start by cutting the problem in half. Suspend the bike from a work stand or hang it up with some rope. Pedal with one hand while hauling on the wire that runs down the downtube. You should see one derailleur move. If its the wrong one moving, pull the other cable. As you add tension, the rear derailleur moves closer to the wheel/an easier gear. The front derailleur goes the other way - gets to a harder gear as you add tension.

The point of that is to see if the issue is in your shifter lever up the top, or the derailleur.

Next is to gently push the derailleur with a finger while pedalling slowly. Do watch out for finger-eating gear bits - possible damage can range from "ouch" to "I can only count to nine and my bike is painted blood red" You are duplicating the action but taking the cables completely out of the picture.

Why? Cables can rust up and mess with shifting. Going around them can show that.

Finally, take some decent pictures of the rear cassette area and post them in your initial question. Then we can go a bit further.

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    +1 for what Criggie has said, if your gears indexed before washing you need to single out the part causing the problem. I would also check the alignment of your rear derailleur as the hanger may have been bent either when cleaning or if you put it in a car. If you stand directly behind the derailleur you should see the jockey wheels perfectly inline with the cassette cog above (if you're in 6 the jockey wheels should be directly below the 6th cog) there is a photo in this link tinyurl.com/hanger-alignment Do what Criggie has suggested and then we can sort it from there. Good luck! – Bikebum Nov 28 '15 at 12:26

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