Press fit BB, lube, dry or Loctite?

[2manyoranges]

My PF30/carbon frame interface is fitted with a little dry PTFE spray. Never creaked.

Dry Ptfe - good call. Carbon/graphite powder would work too - I use that on locks…standard dry lubricant. Doesn’t displace as grease does.

 

[minor_LEGEND]

Even some chalk dust (puncture outfit anyone?)

 

[2manyoranges]

Ah South Downs - our experience that unlike graphite dry lubricant, chalk dust can CAUSE creaking - eg saddle rail and clamp interface.

 

[paton]

https://www.hambini.com/engineering-analysis-grease-or-retaining-compound/

 

[paton]

 

[ChromeChainstay]

gotta love the bike industry taking away theeads, then charging more. Then they reintroduce threads and charge even more. We've been duped. What a frickin' nightmare scenario.

 

[Tootyred]

Progress.....sadly progress driven by marketing, cost saving and poor quality engineering.

Oh...so not really progress...

 

[novocaine]

Progress.....sadly progress driven by marketing, cost saving and poor quality engineering.

Oh...so not really progress...

the Apple principle.

in 50 years we will be looking back at the Apple principle as an economic aberration that could only ever work if people were drawn to shiny things.

 

[bikeworkshop]

Glad to say most brands are moving away from this system.

The problem was caused because you can't put a fine bb thread in carbon - so early carbon frames had a threaded alloy piece bonded into the frame to take a standard threaded bb...

But then racers wanted stiffer cranks, so larger bb axles, and lower q- factor than achievable with ht2, and...
Marketing guys wanted a lighter frame!
So don't bond in the ally threaded piece, just leave a hole!

This system was never meant to creak, so the solutions are varied, depending on cause, quality and materials - as you can see from this discussion.

We've tried and fixed many creaking bbs.
(But not all)
Following the manufacturers instructions and fitting a new bb is usually the first choice.
Sticking rather than lubing is 2nd, but whatever works is great, hopefully without compromising the material, although it's hard to see anything carbon with pf bb being a "bike for life"

But of course a shop doesn't want a non-standard repair to lead to future failure on a high end piece

There are a few brands where once a well-used frame is a couple of years old, and perhaps with a larger rider, it's very challenging. This leads us to believe there can be wear or distortion in the shell.

Cheap crap can creak from new.

There are a lot of clever solutions posted here, to allow a creaky bb sufferer a good chance of a solution.

We occasionally get riders with horrible creaky bbs say:
"Doesn't bother me at all"

The ultimate solution? - change our minds

 

[jim haseltine]

I wrote a long post for this and then deleted it in favour of the short and simple.
Plastic deforms - and 'plastic' is the property of a material to deform up to the point where it fails permanently.
Doesn't matter what is embedded in epoxy, it doesn't change the fact that the stuff is plastic and will deform.
It's like people don't learn from history - back in the 1970s Viscount showed that press-fit BB in steel weren't great yet somebody thought that fitting them in epoxy would work.