Press fit BB, lube, dry or Loctite?

[Splatter Paint]

Hmm, Shimano say no lube, Mapdec used grease on a nylon bb into an alloy shell on the same bike as mine (Giant Defy carbon), most people who use retaining compounds use Loctite 641!

I’d like to assemble dry to start with, but I really don’t want the water moving via capillary action between the bb and shells. Maybe a really thin bead of grease around the outer end of the cup would suffice?

 

[fossala]

I’m pretty sure Specialized say metal press fit bb needs to be bonded to prevent damage.

 

[Guinessisgoodforyou]

641 is medium strength, 648 is high strength.

 

[Shenlong]

Tried Loctite 609 Retaining Compound?

 

[rc300]

Tried Loctite 609 Retaining Compound?

Cure time twice as fast and fractionally stronger bond strength than 614

 

[Sir Neil d'Menture]

641 allows comparatively easily dismantling, albeit with a moderate application of a plastic hammer.
Bike bearings have a habit of needing dismantling.

 

[Splatter Paint]

I went with the barest smear of silicone grease. The nylon bb parts are pressed into paper thin alloy cups which themselves are glued into the carbon frame - I don’t want to whack this setup any harder than necessary!

If it creaks I’ll Loctite it.

 

[rc300]

A thin smear of silicon grease won’t hurt anything …..just steer well clear of lithium based grease as it will gradually deteriorate plastic parts.

 

[d8mok]

I went with the barest smear of silicone grease. The nylon bb parts are pressed into paper thin alloy cups which themselves are glued into the carbon frame - I don’t want to whack this setup any harder than necessary!

If it creaks I’ll Loctite it.

It’ll creak. Maybe not straight away but give it a few miles.

They need either to be dry or the correct loctite compound.

Why grease something that you don’t want to move?

 

[trailstar82]

It’ll creak. Maybe not straight away but give it a few miles.

They need either to be dry or the correct loctite compound.

Why grease something that you don’t want to move?

I’m with Dom on this, it’s a friction / resistance fit so anything lessening that friction is sub optimal. Lock tight possibly but when shimano say not to, then why do it?

My press fit needs fresh epoxy to hold the metal collars in now. A job for another day….burn press fit…shoot it into the sun!!!