HollowTech II Bottom Bracket Question

[scotty72]

I'm going to do a big spring clean of the bike.

Pull it apart etc.

My question is regarding those external BB bearing cups.

I've heard that removing them is a bad idea as it can damage them.
Is this true?

If so, can I assume they are an install once - then throw away item.

I ask as there is a bit of a creak starting up down there. If I need to replace then, I will. Just curious if they are really that fragile.

SCotty

Scotty

 

[alfeng]

I don't believe they are as fragile as you have been led to believe ...

The cups, themselves, can be marred during installation & removal, but that will have little effect on the bearings, themselves.

If you don't have an installation tool, try to get one of Shimano's (very snug fit, so it won't slip).

When you re-install the cups, wrap the threads with some TEFLON plumber's tape -- that may resolve the squeaking problem you are encountering.

BTW. The bearing cartridges CAN be replaced, separately.

 

[scirocco]

Mine say "DO NOT DISASSEMBLE" in large prominent writing. I've never been quite sure if that refers to removal of the BB from the frame (surely not) or to dissasembly of the BB itself.

 

[scotty72]

Mine say "DO NOT DISASSEMBLE" in large prominent writing. I've never been quite sure if that refers to removal of the BB from the frame (surely not) or to dissasembly of the BB itself.

I'm pretty sure (hope) that it means not to pull it apart

BUT!
Then I saw this and am not quite sure how to interpret it.
http://www.shimano.com.au/media/tec...001/SI_0053A_001_En_v1_m56577569830625426.pdf

Look at the paragraph at the bottom = 'Removing and inserting'

Scotty

 

[artemidorus]

I'm pretty sure (hope) that it means not to pull it apart

BUT!
Then I saw this and am not quite sure how to interpret it.
http://www.shimano.com.au/media/tec...001/SI_0053A_001_En_v1_m56577569830625426.pdf

Look at the paragraph at the bottom = 'Removing and inserting'

Scotty

Correct me if I'm wrong, Scotty, but your Shimano pdf seems to refer to something other than a pair of ordinary threaded Hollowtech II BB cups.

 

[Albert 50]

Correct me if I'm wrong, Scotty, but your Shimano pdf seems to refer to something other than a pair of ordinary threaded Hollowtech II BB cups.

http://www.parktool.com/repair/readhowto.asp?id=122

 

[scotty72]

Correct me if I'm wrong, Scotty, but your Shimano pdf seems to refer to something other than a pair of ordinary threaded Hollowtech II BB cups.

No, it linked from the Dura-Ace section under Drivetrains

http://www.shimano.com.au/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441769081&FOLDER%3C%3Efolder_id=2534374302037336&ASSORTMENT%3C%3East_id=1408474395181400&bmUID=1196338396277

Scotty

PS Thanks Albert for the parktools link. Still confused, but it all helps.

 

[alfeng]

Is the REAL question whether or not the Hollowtech II BB bearings can be serviced?

If THAT is the question, then most would suggest that cartridge bearings are designed to be replaced & cannot be serviced.

Cartridge bearings can simply be thought of as "extreme" variants of caged bearings.

If dirt/crud somehow penetrates the "seal" then you can, if you are inclined (in need of service prior to getting new cartridges), gently "peal back"/remove the seal & flush the grease & regrease & replace the seal.

BTW. While probably NOT recommended, if you were on an extended tour in a remote place & needed to service your BB, you could move the left cartridge to the driveside, and vice-versa (except on a GXP BB).

Whether or not you find it easier to replace the BB OR simply install new cartridges in the existing cups will depend on availability & desire + your mechanical inclination.