On a Press Fit BB (PF30) what Retaining Compound and Adhesive Primer do you guys

I didn’t think one used any. Same as a press fit headset.

The pretensioning of the bearings by the cranks means the BB isn’t going anywhere.

A smidge of grease to help ease it in straight & smooth might be more appropriate.

Thanks IGM. Looks like a straight press in then.

Got the tool, wish me luck!.

However, for futher discussion ... some people are saying Park Tool primer & retaining compound. I guess this is carbon ?

and Loctite 609 makes it easier to remove the bearing later which for carbon bores I would use. For Loctite metal 641/680

Thanks.

A lot more rotational force going through a BB - Loctite 641 for me

Thanks, @Smokey_Jo

Is your frame Ali ?

Better go and check my Loctite collection.

Interesting, I’ve just gone straight in with a bit of lube.

@jkomo

Ohh. Err..

Yup a Commencal, I made the mistake of using grease the first time and all it did was encourage the cups to rotate. This started creaking after a few rides. 12 months on after refitting using 641 I'm creak free.

Liking the sound of 641.

Thanks.

RT

If PF30 is meaning 30mm axle in a pressfit frame expect to change bearings a lot. I had a YT Jeffsy cf with this set up, bearings were seized after around 2 months every time

Don't ask me because despite my best efforts with spotless surface prep, Loctite primer and first 641 then a second go with 638, my pressfit BB still creaks.

I'm going to buy a new frame, pressfit can FRO.

@finbar - time for the 2-pack epoxy ?

That's not a bad shout actually, might do that. I can probably lever the bearings out the cups when they need changing.

I should also add it's one of those whizz-bang thread together Praxis BBs, that didn't help either - I think the BB shell in the frame (Neil Prude Bura SL) is just totally the wrong size. Hambini would probably implode if he looked at it.

Depends on the sizes frame and cups and what the interference fit is going to be. I would measure both before installing. Sometimes the frame needs reamed to size, occasionally turn cups down if the frame cannot be reamed to size. Loose fits need to be bonded in. Loctite have a range of products depending on the level of press fit, gap size etc. Most retaining compounds soften with heat, so you can use a heat gun in the future to aid removal if required.

Permanently installing a press fit BB with replaceable bearings often sorts creaks. Screw together ones help with alignment if bonding into a really loose frame, just check internal clearance first.

I normally aim to follow the manufacturers instructions in the first instance unless there is a reason not to. One big brand frame manufacturer used to spec grease, but if it creaked then use retaining compound (as they did not appear to be able to control their BB bore IDs accurately enough for a reliable press fit)

Try RScomponents for their medium strength retaining compound, we use it in our workshop with no problems, and it's much cheaper than Loctite.