Gravel / Gravé / Gnarmac / Groad / ATB

Press-fit yes, but seems to be bash-remove. I'm not sure that removing a PF BB from one bike and reinstalling it on another is possible after hammering it out. You can do it with threaded ones.

Again I didn't want to clog up the whole thread with arguments about PF BBs, I was just curious about the creaking specifically

Yeah i realised I was wrong. I think because psee had one as well as one of those super cheap steel all road frames that had the PF30 nobody could get to work

Bishbashbosh would probably be very suitable if the geo fits and you get it on sale

Easily. As long as you don't go full neanderthal on it and use the right tools; the same could be said for threaded ones.

If you get to design a frame would you put a PF bb in there while there's a proven does-the-same-thing solution?

Even better would you put a PF bb in your custom frame?

If anybody thinks PF30 is a good idea, they've fallen for marketing ploys. 30mm cranks and bbs may be a good idea but press fit only exists to allow manufacturers to be sloppier building their frames where bb30 would creak and annoy customers.

AHEM

I've replaced about 10 threaded BBs. Never needed to replace a pressfit BB.

Nice!

30mm cranks and bbs may be a good idea but press fit only exists to allow manufacturers to be sloppier building their frames

Nah it provides better sealing than BB30 - works well on MTBs and cross bikes. In my anecdotal experience anyway.

The bearings are cheap, press them in and leave them in until they wear out. Then drift them out and press in new ones.

Probably. I rode my caad12 through muddy country lanes in the rain for 2 days at christmas and killed a set of bearings.
Anyway, don't interrupt my ranting with your logic!

...

I'm afraid you're too far gone 😋

I've replaced about 10 threaded BBs. Never needed to replace a pressfit BB.

What does this mean?

Amazing paint!

Clearly evidence that big spindles make you better looking or something... :-)

I think it's fairly obvious that the comparison between a bottom bracket, through which all one's mighty power flows, and a headset, which simply has to keep the front wheel pointing in vaguely the correct direction, is an entirely spurious one.

You say PressFit BB's are stupid, yet most of the worlds industries press bearings in rather then screw them into threads (or push them into cups to be then screwed into threads?!?!). They've been doing it for a long time, and it's been working pretty well so far.

Not into carbon fibre bearing housings though. That's one thing that people who use composites a lot like F1 teams and aeronautical engineers try very, very hard to avoid. If you look at an F1 gearbox with a composite housing, all of the bearing carriers will either be bolted on or will be alloy shells co-moulded into the housing. You can't get sufficiently tight tolerances with carbon alone.

Or was it to make production cheaper, skipping the threading

That is usually how these things tend to go:
A design that is 'better' in some marketable ways and after x years and y sales will be cheaper to produce. And by the end of the product cycle that saving will have covered most development costs.

Really, they could just follow Amey's Pinterest, take some notes and go riding.

Or was it to make production cheaper, skipping the threading

Also to avoid having metal inserts in the BB area, as trying to mould threads into carbon tends to be doomed to failure.

I have that super cheap all road frame. And it works.

Yeah, my point was that pressing in a headset is no bother because (at least in my case) you only do it once every 5 years or something, for the reasons that you state. Convenience for maintenance is less of a factor than for a BB.

Yep, good point.

Naturally. I'm not disparaging that there might be limitations and/or exceptions. I was highlighting that as general practice, we've gotten pretty ok at pressing bearings.

I'm not a materials scientist, but I don't think the loads exerted on bearings used for high performance parts will compare to a human powered bicycle. I can grasp the limitations and in a sense, the flexibility of the material in comparison to say...an alloy shell, but I'm being quite general.
Most of the complaints regarding press fit creaking I've actually experienced were on aluminium frames rather than carbon, which surprises me as I'd have thought we have got pretty good at machining or casting to high tolerances.

Trying to do the machining on the cheap...that's the problem.

Going for it, knocked a bit extra off the price. Just gotta find some forks and wheels now and I can pretty much chuck it together. I’ll be pestering you for a wheel build some time this year. Dyno front at some point. Not soon though. Will pay with money plus beer if you fancy it