Author Topic: Eccentric bottom bracket - how to lubricate?  (Read 1368 times)

Eccentric bottom bracket - how to lubricate?
« on: May 09, 2018, 07:54:41 pm »
The eccentric bottom bracket at the front of the Moulton tandem is getting harder and harder to adjust. What is the recommended method and lubricant to ease it?

It has a pair of clamp bolts to secure it, and is rotated by "spanner" with two prongs that fit into holes in the right hand side.

Re: Eccentric bottom bracket - how to lubricate?
« Reply #1 on: May 09, 2018, 08:02:31 pm »
Moulton tandem, you say.
Is there such a thing?
Pictures, or it doesn't exist.
Pls & Thx.

LittleWheelsandBig

  • Whimsy Rider
Re: Eccentric bottom bracket - how to lubricate?
« Reply #2 on: May 09, 2018, 08:09:12 pm »
There have been quite a few Moulton ATBs modified to tandems, convertible back to solo, mostly in Oz. More recently, the same thing has been done to several APBs, mostly in the UK.
https://www.flickr.com/photos/13469967@N02/6141660173/lightbox/
Wheel meet again, don't know where, don't know when...

Re: Eccentric bottom bracket - how to lubricate?
« Reply #3 on: May 09, 2018, 08:14:39 pm »
Blimey!
Every day is a school day....  :thumbsup:

Re: Eccentric bottom bracket - how to lubricate?
« Reply #4 on: May 09, 2018, 09:31:04 pm »
remove the eccentric, clean (eg by wire brushing) both the housing and the eccentric itself, coat both surfaces liberally with anti-seize (eg copper ease) and reassemble.

While you are at it, check the lower tie rod welds where they join onto the seat tubes; they sometimes crack on APBs anyway and this is obviously more likely in the case of a tandem version.

hth

cheers

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Eccentric bottom bracket - how to lubricate?
« Reply #5 on: May 09, 2018, 09:41:11 pm »
remove the eccentric, clean (eg by wire brushing) both the housing and the eccentric itself, coat both surfaces liberally with anti-seize (eg copper ease) and reassemble.

While you are at it, check the lower tie rod welds where they join onto the seat tubes; they sometimes crack on APBs anyway and this is obviously more likely in the case of a tandem version.

hth

cheers

If either the bearing shell or the bottom bracket is aluminium do not use copper (what ever you call it)  It can cause issues, hence alu slip was invented ;)

I'd use marine grease.  Also it is blue and everything blue is better such as bluetooth.

Re: Eccentric bottom bracket - how to lubricate?
« Reply #6 on: May 09, 2018, 09:50:48 pm »
Rocol copper ease is made to a Royal Navy specification that recommends it as suitable for all metal combinations.

Note that most copper greases contain both graphite and copper.

In this case you have an aluminium eccentric in a steel shell. Spending a fortune on an aluminium anti-seize is a waste of time.  The conditions that favour the use of a 'matching' anti-seize are actually quite narrow and perhaps are not likely to be found on a bicycle anyway.

cheers

Gattopardo

  • Lord of the sith
  • Overseaing the building of the death star
Re: Eccentric bottom bracket - how to lubricate?
« Reply #7 on: May 09, 2018, 10:25:48 pm »
So copper doesn't react with aluminium in the Navy.

PS I know they don't use copper (whatever you call it) on the flying machines that they have.  But hey ho lets have a pissing contest. 

Re: Eccentric bottom bracket - how to lubricate?
« Reply #8 on: May 09, 2018, 10:58:40 pm »
There have been quite a few Moulton ATBs modified to tandems, convertible back to solo, mostly in Oz. More recently, the same thing has been done to several APBs, mostly in the UK.
https://www.flickr.com/photos/13469967@N02/6141660173/lightbox/

That's my ATB tandem! Since been ARCC e-assisted.

Re: Eccentric bottom bracket - how to lubricate?
« Reply #9 on: May 09, 2018, 10:59:40 pm »
remove the eccentric, clean (eg by wire brushing) both the housing and the eccentric itself, coat both surfaces liberally with anti-seize (eg copper ease) and reassemble.

While you are at it, check the lower tie rod welds where they join onto the seat tubes; they sometimes crack on APBs anyway and this is obviously more likely in the case of a tandem version.

hth

cheers

Thanks Brucey!

LittleWheelsandBig

  • Whimsy Rider
Re: Eccentric bottom bracket - how to lubricate?
« Reply #10 on: May 09, 2018, 11:11:32 pm »
There have been quite a few Moulton ATBs modified to tandems, convertible back to solo, mostly in Oz. More recently, the same thing has been done to several APBs, mostly in the UK.
https://www.flickr.com/photos/13469967@N02/6141660173/lightbox/

That's my ATB tandem! Since been ARCC e-assisted.

Why do you think I picked that photo? ;-)
Wheel meet again, don't know where, don't know when...

Re: Eccentric bottom bracket - how to lubricate?
« Reply #11 on: May 10, 2018, 03:20:05 am »
What Brucey says, but if you have trouble talking it out here's a handy technique from Thorn, assuming it's a similar design
https://www.youtube.com/watch?v=XdFLDSeK7LY

Re: Eccentric bottom bracket - how to lubricate?
« Reply #12 on: May 10, 2018, 07:08:11 am »
What Brucey says, but if you have trouble talking it out here's a handy technique from Thorn, assuming it's a similar design
https://www.youtube.com/watch?v=XdFLDSeK7LY

I was pleased to see that the mechanic stopped using the nutdriver handle for a hammer. That'd have you got you a smack in the ear when I was an apprentice.  :)
I hope he put Copper Ease in after the video was finished.
Never knowingly under caffeinated

Re: Eccentric bottom bracket - how to lubricate?
« Reply #13 on: May 10, 2018, 12:50:01 pm »
What Brucey says, but if you have trouble talking it out here's a handy technique from Thorn, assuming it's a similar design
https://www.youtube.com/watch?v=XdFLDSeK7LY

Thanks, just using the penny washer technique is enough to rotate it, no need for removal.

When converting between solo and tandem I have to adjust it most, to get the connecting chain on and off. Maybe I should fit a chain with a quick link instead.