BB External bearings - The cheap rebuild

100Tours's Photo 100Tours 04 Oct 2016

anyone want to buy an enduro bearings bb bearing puller/press for this job..

Make me an offer?

Attached Images

  • image.jpg
  • image.jpg

Edited by GotThatInCarbon, 04 October 2016 - 07:44 .

JXV's Photo JXV 05 Oct 2016

All the failed Shimano 24mm BB's I have stripped had water damage. None were brinelled or broken. This tells me the sealing is the biggest challenge to longevity.

There is only a single lip seal that seals against the outer plastic cover and the ball bearings are openly visible when you remove the cover and leave the seal in place. They are well greased when new but generally not maintainable. Designed to fail after a while.
The seals on BB70 and BB93 are slightly better but still only a single thin lip. A lot of dirt accumulates between the cover and the outer surface of that seal and you cannot easily clean it.

Replacing the bearings is all well and good but unless you also renew the seals it won't last very long. I reckon stainless steel bearings and better seals would significantly improve life....if available.

Using even a gentle spray of water from a hose while washing the bike and submerging bb (e.g. in a stream crossing) will almost certainly cause water to get in.

If you are careful you can lift the plastic cover, gently clean dirt off the seal and inject grease to keep your BB alive for longer.

Sent from my SM-G935F using Tapatalk
Edited by JXV, 05 October 2016 - 08:00 .

BaGearA's Photo BaGearA 09 Nov 2016

So just to be clear , I need to cut off this rim around the inside of the spacer to make it work right?

 

I am using normal 6805 bearings from bearing man.

 

Please advise also on how you cut them off ??  I'm thinking of just using one of my very small files and jsut filling it down flush.

Attached Images

  • 20161109_120716.jpg
  • 20161109_120722.jpg

JXV's Photo JXV 09 Nov 2016

So just to be clear , I need to cut off this rim around the inside of the spacer to make it work right?

I am using normal 6805 bearings from bearing man.

Please advise also on how you cut them off ?? I'm thinking of just using one of my very small files and jsut filling it down flush.

I would go with carefully filing the lip of the part that presses into the bearing. If that dont work just cut the last 1 to 2mm off entirely.

Sent from my SM-G935F using Tapatalk

BaGearA's Photo BaGearA 09 Nov 2016

I would go with carefully filing the lip of the part that presses into the bearing. If that dont work just cut the last 1 to 2mm off entirely.

Sent from my SM-G935F using Tapatalk

Have you done this bodge ?

JXV's Photo JXV 09 Nov 2016

Have you done this bodge ?

Not the filing part but I ended up with 2 new right hand cups at some stage and extracted the healthy OE shimano bearings from these to replace worn out bearings in a set of BB70 cups. The one plastic end cap clipped right in because the OE bearings have the recess, but the other cap was damaged so I cut the end off to make it fit better. If the lip wasn't damaged I would have preferred to file it. That BB is on a bike now and functioning normally.

I have an old worn out 24mm crank arm that I can slide the cap over. Makes it easy to see the raised lip and file it flush so I will do that on the next one.

Just to be sure .... I am talking about the slightly thickened edge on the inboard side of the BB end caps.


I havent yet fitted aftermarket bearings to Shimano BB cups 'cos I have managed to scrounge unused or healthy used oe bearings each time.


Sent from my SM-G935F using Tapatalk
Edited by JXV, 09 November 2016 - 03:07 .

Pikey's Photo Pikey 21 Feb 2017

Probably a stupid question . I can't find anything that says it's possible and as far as I know it's not. But is there an BB adapter that will allow you to use a bb30 on a gxp 73mm threaded BB....

BaGearA's Photo BaGearA 21 Feb 2017

Probably a stupid question . I can't find anything that says it's possible and as far as I know it's not. But is there an BB adapter that will allow you to use a bb30 on a gxp 73mm threaded BB....

no you can't

 

 

You get adaptors to run GXP in BB30 but not the other way around

BaGearA's Photo BaGearA 21 Feb 2017

no you can't

 

 

You get adaptors to run GXP in BB30 but not the other way around

Are normal spindles nor 24mm and BB30 30mm ??  Thats how I understand it and that makes it quite obvious that BB30 wont go into A Threaded shell , because I doubt the shell on my bike is even 30mm wide. 

Pikey's Photo Pikey 21 Feb 2017

Are normal spindles nor 24mm and BB30 30mm ??  Thats how I understand it and that makes it quite obvious that BB30 wont go into A Threaded shell , because I doubt the shell on my bike is even 30mm wide.

As I thought 👍

the nerd's Photo the nerd 21 Feb 2017

no you can't

 

 

You get adaptors to run GXP in BB30 but not the other way around

 

 

Like these? 

 

BSA 30 bb's that people make? 

 

:thumbup:

 

BB231Q02.jpg

Pikey's Photo Pikey 21 Feb 2017

Like these? 
 
BSA 30 bb's that people make? 
 
:thumbup:
 
BB231Q02.jpg

Thanks dude have just been told same thing . Will source one tmw 👍

100Tours's Photo 100Tours 16 Aug 2017

anyone want to buy an enduro bearings bb bearing puller/press for this job..

Make me an offer?

 

Forgot who I sold this to :-$, but I've found an extra shift for the tool in my toolbox. PLease make contact and I'll send it to you.

_im_from_earth's Photo _im_from_earth 16 Aug 2017

Probably a stupid question . I can't find anything that says it's possible and as far as I know it's not. But is there an BB adapter that will allow you to use a bb30 on a gxp 73mm threaded BB....

 

There are a few options, RaceFace, Rotor, Wheels MFG. The only thing to watch out for is spindle length on your BB30 crankset. The older BB30 cranks will not work, you need a crank that is BB30/PF30 compatible.