Author Topic: Bottom bracket lubrication  (Read 1207 times)

TerryField

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Bottom bracket lubrication
« on: December 20, 2019, 03:17:46 PM »
Been out on the Mercury this morning in some pretty deep water! Rohloff hub and bottom bracket fully submerged on several occasions by floods.

I will be changing the gearbox oil, but should I also regrease the bottom bracket? If so, how easy is it given the presence of the eccentric chain adjuster?

Many thanks

Terry

energyman

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Re: Bottom bracket lubrication
« Reply #1 on: December 20, 2019, 04:00:50 PM »
My LBS suggested that I pour some engine oil down the seat tube.
Which I did.
It stopped the squeaking but only God knows what the longer term effect will be.
It is on an old Post Office Pashley Courier bike which, I have been assured by Peter our Post Man, are bomb proof !
« Last Edit: December 20, 2019, 04:03:06 PM by energyman »

mickeg

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Re: Bottom bracket lubrication
« Reply #2 on: December 20, 2019, 04:31:08 PM »
If it was me, I would do the Rohloff oil change a couple times, first right away and the second time maybe a couple weeks to a month later.

Bottom bracket, there are so many types of bottom bracket bearings, difficult to say.  The old cup and cone ones that nobody uses any more are the only ones where you can easily clean the bearings and re-grease.

I trust you do not have a dynohub.

Chain likely needs some new lube too.

CAM

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Re: Bottom bracket lubrication
« Reply #3 on: April 05, 2020, 09:03:57 PM »
Hello,
I have the same problem (although it seem that the flood I went through wasn't so deep - only bottom bracket deep).  The Thorn Mega Brochure says this:
If a frame is submerged, or if you cycle with your BB submerged (as may happen during floods) you should, at the earliest opportunity, remove the BB and let it and the frame dry.

So my question is: how to do this for a Mercury ?  Is it  necessary for a very quick dunking ?

Thank you

  Caroline

Danneaux

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Re: Bottom bracket lubrication
« Reply #4 on: April 05, 2020, 09:31:00 PM »
Hi Caroline, and welcome to the Thorn Cycling Forum!
Quote
I have the same problem (although it seem that the flood I went through wasn't so deep - only bottom bracket deep).
Uh-oh.  ???
Quote
The Thorn Mega Brochure says this:
If a frame is submerged, or if you cycle with your BB submerged (as may happen during floods) you should, at the earliest opportunity, remove the BB and let it and the frame dry.

So my question is: how to do this for a Mercury ?
Dave Whittle, former Thorn Workshop director, late of this Forum and a very nice fellow, made a helpful video showing how to remove an eccentric from a Mercury. See: https://www.youtube.com/watch?v=XdFLDSeK7LY
Quote
Is it  necessary for a very quick dunking ?
I would, under the reasoning better safe than sorry and better now than later. It doesn't take much water to get inside and cause problems at a later date.

If water is trapped inside and above the eccentric it can cause corrosion. Removing the eccentric (after first removing the crank arms) allows any trapped water to drain. Coating the inside of the tubes with oil or similar is a good idea too. Before reinstalling, be sure to use a good anti-seize to prevent galvanic corrosion ("cold-welding"/sticking) between the eccentric and steel bottom bracket shell.

Best,

Dan.
« Last Edit: April 05, 2020, 11:01:05 PM by Danneaux »

PH

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Re: Bottom bracket lubrication
« Reply #5 on: April 06, 2020, 11:52:34 AM »
If I have a wet ride the first thing I do when I get home is remove the seatpost and hang the bike upside down in a warm room. 
The chances are you don't need to do anything, but as Dan says better safe than sorry and if you want to be 100% there's no water in there, the only way is to remove the BB.  Just a couple of points about Dan's instructions - the video is for a seized EBB, in normal removal you just loosen the screws, give it a wiggle and slide it out.  Also if you're lazy, you only have to remove a single crank.
It's a good idea to periodically air a frame out even if you haven't been riding through floods, water often finds a way in plus there's condensation. Seatpost and EBB out and leave somewhere warm overnight.  Bit of grease when you put them back ensures it's an easy job next time.