Press fit BB, lube, dry or Loctite?

Loctite retaining compounds all expand as they cure and will cause damage to most plastics and make them brittle and prone to cracking. I've seen quite few frames paintwork bubble and flake when any excess compound is not cleaned off properly when applied.

Plastic cups are never perfect and will deal with some small amount compression when installed....... A get out of jail free card for some frame manufacturers 😂
 
Glad you used grease and not Loctite

Why? Because plastic does not like it at all

From skiing:

Loctite is very harmful to some of the plastics of which bindings are composed and if it comes in to contact with such the plastic will fail within a short period of time and without any signs of there being an issue. For this reason Quiver Killer only certifies the use Vibra-TITE VC-3 threadlock which is a non-anaerobic formula that is benign to all plastics.
 
Water had seeped in between the bb and aluminium frame cup causing corrosion. This is what I’m trying to avoid by a smear of silicone. Mapdec on YouTube had the same issue on an identical Defy and when they drifted the bb out, the glued in cup came with it!

My logic is I can add Loctite later, but if I can prevent water ingress and aid easier disassembly and avoid ‘damage’ to the frame it has got to be worth a go!
 
I'm struggling to follow this discussion.
Press fit bottom brackets can squeak. That is the outcome of metal moving against metal. That generates friction which manifests itself as heat and noise. Basic Laws of Physics. I can just above see the logic, twisted though it is, of using grease as an interface. A door hinge squeaks for exactly the same reasons and a touch of lube stops the noise. Until the lube dissipates and the squeal reappears. Then you reapply lube. It is easy on a door hinge, somewhat more difficult with a bike.
The way to stop the squeak is to stop the friction and the way to stop the friction is to stop the movement. Hence bearing compound. You don't need a lot. Those who say that force enought to break the frame is needed for removal are both using too much compound, your technique is sadly adrift and/or you are riding a frame that is weak to begin with.
The comments attributed to various and always unnamed bike shops that the housing has worn out of shape are hard to believe. If these comments have been made by any experienced machanic then the assumption must be that he simply CBA sorting out the problem.
Then I wonder why Loctite will destroy your frame. Why are you putting loctite on your frame? It is bearing compound to fit between the outer surface of the bearing and the inner surface of the housing. If you are lathering your frame with bearing compound I respectfully suggest that you are better off not doing any bike maintenance at all.
This really is a very simple problem with an equally simple solution. There does appear to be a lot of overthinking taking place. I have had three bikes with press fit BBs. They all squeaked virtually from new. They never squeaked when the bearings were fitted properly. Manufacturers don't do it for reasons of economy. LBS don't do it on PDI using the ostrich principle.
QED.
 
I'm struggling to follow this discussion.
Press fit bottom brackets can squeak. That is the outcome of metal moving against metal. That generates friction which manifests itself as heat and noise. Basic Laws of Physics. I can just above see the logic, twisted though it is, of using grease as an interface. A door hinge squeaks for exactly the same reasons and a touch of lube stops the noise. Until the lube dissipates and the squeal reappears. Then you reapply lube. It is easy on a door hinge, somewhat more difficult with a bike.
The way to stop the squeak is to stop the friction and the way to stop the friction is to stop the movement. Hence bearing compound. You don't need a lot. Those who say that force enought to break the frame is needed for removal are both using too much compound, your technique is sadly adrift and/or you are riding a frame that is weak to begin with.
The comments attributed to various and always unnamed bike shops that the housing has worn out of shape are hard to believe. If these comments have been made by any experienced machanic then the assumption must be that he simply CBA sorting out the problem.
Then I wonder why Loctite will destroy your frame. Why are you putting loctite on your frame? It is bearing compound to fit between the outer surface of the bearing and the inner surface of the housing. If you are lathering your frame with bearing compound I respectfully suggest that you are better off not doing any bike maintenance at all.
This really is a very simple problem with an equally simple solution. There does appear to be a lot of overthinking taking place. I have had three bikes with press fit BBs. They all squeaked virtually from new. They never squeaked when the bearings were fitted properly. Manufacturers don't do it for reasons of economy. LBS don't do it on PDI using the ostrich principle.
QED.

The BB is nylon in this case.

Shimano advise going in dry.

Some manufacturers recommend a compound if it creaks.

It’s a crap system to be fair and I’m glad to see many returning to threaded.

My Colnago has a T45 so when it does start to creak (currently using a dry fitted Shimano) I’ll go for a ceramicspeed or similar which is threaded.
 
The housing is nylon?
Wow.
That will eliminate metal on metal friction but metal can still experience friction against hard plastic.
In that case I've no idea how to stop the noise. Or the wear possibly leading to distortion, presumably at 3 o'clock and 9 o'clock.
Seems like a cheap manufacturing process. Cost cutting as usual.
Probably a Hollowtech type converter is the only solution. Which, of course, means a new crankset as well.
Hmm!
 
The Shimano nylon bb parts are straight out of the mould, no machining, often going into either a carbon frame with piss-poor tolerances or a machined alloy bb shell with piss-poor tolerances which was machined before the frame was welded. The nylon then hopefully distorts enough to keep it all ship-shape - without squishing the bearing.

The BB30 derivative PF30 works on the same principal, bearings are pressed into the plastic shells then the whole shebang pressed into the frame.

I did the wheel bearings on my motorbike the other day - they’d lasted 20 winters. No drama, tapped them out of the hub, put the new ones in the freezer, they went in easy… and that was that. No products needed, just a correct interference fit.
 
Pssst

A secret

Don’t use Loctite on a plastic shelled bearing housing (reasons above)

Don’t use grease (it will displace and then things will creak)

Do use a very thin smear of clear silicon bath sealant (it will give off acetic acid when curing…which WILL affect carbon fibre so don’t use more than a tiny tiny smear on the bearing housing in the metal cup … and that will stop the creaking since once cured it’s not going anywhere…and still allows you to punch or pull out the bearing…and stops water ingress too).
 

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