Rattl'y Creak From Rear Derailleur

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Psamathe
Posts: 17650
Joined: 10 Jan 2014, 8:56pm

Rattl'y Creak From Rear Derailleur

Post by Psamathe »

On Tadpole bent, yesterday decided to clean chain and cogs (and tubes) before heading off for a bit (maybe). They were not very dirty.

Cleaning cassette was brushing (paint brush) degreaser over cogs with wheel held over at an angle to avoid getting it into bearings and wheel rim, then a rinse of with water without force (i.e. gentle flow).

But on ride today there is a sort of creak/rattle coming from rear cassette sometimes on pedal push. It comes and goes and does not seem to depend on what gear. Pedalling backwards does not cause it. When it happens it starts when pushing point on pedals (on bent wither crank vertical). And worse when you push harder. At times it goes and then restarts. sometimes keeps going continuously (e.g. when going uphill).

I tried adjusting the alignment (easy on bent as I have a barrel adjuster on the cable just below the bars so can adjust whilst riding) and makes no difference.

Chain and cassette not worn (LBS checked the other day). After cleaning I tend to over oil chain, leave overnight then wipe of excess - oiled with wet lube applying to every chain bearing but didn't get round to wiping excess off before ride so should be more than enough oil.

It's not a "high quality" chain brand (bent built at time of pandemic when choice of parts was limited so I assume they used whatever chain they could get hold of).

Edit: Plus a little GT85 to bearing points on jockey wheels and rear derailleur.

Any ideas?

Many thanks
Ian
Jdsk
Posts: 24640
Joined: 5 Mar 2019, 5:42pm

Re: Rattl'y Creak From Rear Derailleur

Post by Jdsk »

Usual homily: sounds can come from many and misleading places.

Can you reproduce it when you're off the trike?

You've checked the chain alignment. How many chains tubes, idlers etc are there? Can you touch them when the creak creaks? And if you can is there anything to feel, and does touching them affect the noise?

Jonathan

PS: Solvent or surfactant?
rareposter
Posts: 1993
Joined: 27 Aug 2014, 2:40pm

Re: Rattl'y Creak From Rear Derailleur

Post by rareposter »

I'd guess you've just loosened some grit/dirt etc in the cassette / rear mech / chain and it's sort of swilling around in there now, grinding away every time it gets caught up somewhere.

I normally take the cassette off to give it a thorough clean - avoids any issue with degreaser + water anywhere near bearings and also ensures there's no grit left in the recesses of cassette teeth.
Psamathe
Posts: 17650
Joined: 10 Jan 2014, 8:56pm

Re: Rattl'y Creak From Rear Derailleur

Post by Psamathe »

Jdsk wrote: 4 Jun 2023, 3:02pm Usual homily: sounds can come from many and misleading places.

Can you reproduce it when you're off the trike?

You've checked the chain alignment. How many chains tubes, idlers etc are there? Can you touch them when the creak creaks? And if you can is there anything to feel, and does touching them affect the noise?

Jonathan

PS: Solvent or surfactant?
Can't reproduce off the trike - needs pressure on the pedals moving forwards to cause it (variable how much, sometimes it's just at the peak push (cranks vertical on bent), sometimes it's continuous whilst pedalling. Stop pedalling and noise stops.

Very definitely sounds like rear derailleur/cassette/jockey wheels. In my (inexperienced) mind I eliminated the jockey wheels as pedalling backwards does not cause it and they don't get to experience the pressure when pedalling (much). Nearest idler is enough of a different direction that I'd tell if it was from that (it's a fairly low "laid back" bent).

Can't really touch when making noise as you have to be pedalling and thus reaching round behind without looking near cassette/chain/etc. I thought not a good plan. Stationary I have tapped derailleur and other bits in area and nothing seems lose.

To clean cassette rear wheel was taken out (actually changed inner tube at same time) - but all back no issues and QR done sensibly tight.

Ian
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