Thorn Cycles Forum

Community => Thorn General => Topic started by: StillOld on June 26, 2017, 10:53:06 AM

Title: Gritty sound from eccentric bracket bearings?
Post by: StillOld on June 26, 2017, 10:53:06 AM
Next silly question.....I wiped the whole bike down on my return from the Hebrides and cleaned the chain and every nook and cranny I could think of. However I still have a slightly gritty sound when the bike is inverted and the crank turned. I am loathe to take anything apart down there.

I imagine some sand or similar has entered somewhere in the system....is it a sealed unit or has it got accessible bearings that should be cleaned and re greased?
Title: Re: Gritty sound from eccentric bracket bearings?
Post by: geocycle on June 26, 2017, 01:50:58 PM
Most likely that this is residual dirt in the chain rollers, or a bit of wear in the sprocket/chain ring.  It is likely to disappear quickly when you you oil it up, start riding and let it bed-in again. If it doesn't then you need to go through components systematically.  Sealed components such as the BB are less likely than chain-sprocket-chain rings but do eventually go.
Title: Re: Gritty sound from eccentric bracket bearings?
Post by: StillOld on June 26, 2017, 03:37:42 PM
Looks like you may be right....I sat down with a toothbrush and WD40 and gave the chain and sprockets another going over....a light oil and it definitely sounds better. I will take a wander this evening and see how it goes...thanks.
Title: Re: Gritty sound from eccentric bracket beabrings?
Post by: Matt2matt2002 on June 26, 2017, 06:47:47 PM
Ever thought about a Hebie Chainglider?
I've had one on my Raven for 3+ years.
Certainly appreciated it when up to both axels in mud a few years ago.
Lots of posts on the forum about the pros and cons.
Definitely protect the chain from a fair bit of grit n sand.
Title: Re: Gritty sound from eccentric bracket bearings?
Post by: StillOld on June 27, 2017, 11:13:10 AM
That looks interesting...and SJS do one for the Rohloff...if I was playing in the sandy coast again I might consider that. I will read up on it. Thanks.
Title: Re: Gritty sound from eccentric bracket bearings?
Post by: geocycle on June 27, 2017, 11:58:47 AM
Key point is the number of teeth on your chainring and sprocket as this has to match the chainglider.  I think you have a nomad so the chainglider would work well with that frames clearances I think.  For protracted use on gritty surfaces or just to extend chain longevity they can be a useful investment and save the need to spend time cleaning chains.  I used one successfully for a year or so on my Raven Tour but struggled to get it work with the tighter raven sport tour frame.
Title: Re: Gritty sound from eccentric bracket bearings?
Post by: Danneaux on June 27, 2017, 09:39:05 PM
Quote
... I still have a slightly gritty sound when the bike is inverted and the crank turned.
If it is too hard to find the source, your LBS has the solution -- for a price!  ;)

Pic below.

All the best,

Dan.
Title: Re: Gritty sound from eccentric bracket bearings?
Post by: George Hetrick on June 28, 2017, 01:05:56 AM
Prices have gone up quite a bit since that sign was made  8)
Title: Re: Gritty sound from eccentric bracket bearings?
Post by: StillOld on June 28, 2017, 11:20:04 AM
Oh dear...my crunch crunch sound may be prohibitive to fix...
Title: Re: Gritty sound from eccentric bracket bearings?
Post by: geocycle on June 28, 2017, 02:25:55 PM
Oh dear...my crunch crunch sound may be prohibitive to fix...
A crunch is not even on Dan's list -priceless!
Title: Re: Gritty sound from eccentric bracket bearings?
Post by: mickeg on June 28, 2017, 10:49:49 PM
If those prices include parts, I would have been happy to pay it the last time I had a clicking sound.  But I suspect parts are extra at a suggested manufacturer full price.