From threaded to press fit and back to threaded again?

[sadisticnoob]

Been noticing the trend , more and more bikes are moving towards T47 as a standard.

It seems to be so long ago , but what was the reason why we moved from BSA to pressfit and now back to T47?

[ooo]

Pressfit spec is good in theory, but in practice only a few mfgs was able to follow pressfit tolerance. Most bikes that was advertised as pressfit bikes was shipped with out of spec bb.

[Aeo]

Pressfit is lighter and cheaper to manufacture. On paper, the better way to do bottom brackets. Less parts and stiffer (probably more advantages I am forgetting)

Threaded is more forgiving during assembly, easier to replace for bike shops and end users.

In the real world where bicycle frames are predominantly produced in low-wage countries, whether alloy, metal or composite, consistently making good pressfit appears to be too hard. Additionally, a bad reputation for pressfit bikes has been accumulated among bike reviewers and large parts of customers.

Threaded bottom brackets can hide inaccuracies and careless manufacturing better than their pressfit counterparts.

Logical outcome is bike brands going back to threaded bottom brackets, even if it comes with considerable downsides for some bike designs.
An example would be the Specialized Diverge, a modern gravel bike with a massive tyre clearance but an ancient and narrow BSA bottom bracket. The result is a solid carbon chainstay which leaves no option but to route rear derailleur connections externally.

[wheelbuilder]

Pressfit spec is good in theory, but in practice only a few mfgs was able to follow pressfit tolerance. Most bikes that was advertised as pressfit bikes was shipped with out of spec bb.

"Most" were out of spec? Don't think that is accurate.

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[CampagYOLO]

I can't say that I ever enjoyed hammering out old pressfit bearings. At least threaded BB's mean you don't have to do this.

[Maddie]

With the proper tools, you never have to hammer out a BB bearing

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[MagicShite]

I can't say that I ever enjoyed hammering out old pressfit bearings. At least threaded BB's mean you don't have to do this.

The full kit tool for pressfit BBs are cheap and not expensive at all. You can also repurpose them for edge cases (extremely rare)

With threaded BBs I have to keep stock of those pesky different standards and they all get super expensive REALLY quickly.

Plus not to mention tightening them down is a PAIN IN THE ASS with the small lips on some of these threaded BBs.

I really hate threaded BBs, I have more creaks with them than good BB86. /end rant.

[Steve Curtis]

If the same frame had a T47 and press fit option, I'd take the press fit every time.
I've never had an issue with any pressfit frames, or old bb30 with the big C clip.

Just a quick count back, that's 12 frames since 2010, and I still have some of them now. (Most are Cervelos or Cannondales)

[kode54]

With the proper tools, you never have to hammer out a BB bearing

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This. I use an extractor that fits on the bearing races like the Enduro and/or wheels manufacturing tool to do the job.

I’m not a good aim and when it comes to using a hammer on a carbon frame….

[CampagYOLO]

With the proper tools, you never have to hammer out a BB bearing

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Even with BB30 bearings inserted into the frame?

[CampagYOLO]

I can't say that I ever enjoyed hammering out old pressfit bearings. At least threaded BB's mean you don't have to do this.

The full kit tool for pressfit BBs are cheap and not expensive at all. You can also repurpose them for edge cases (extremely rare)

With threaded BBs I have to keep stock of those pesky different standards and they all get super expensive REALLY quickly.

Plus not to mention tightening them down is a PAIN IN THE ASS with the small lips on some of these threaded BBs.

I really hate threaded BBs, I have more creaks with them than good BB86. /end rant.

Oh threaded isn't perfect, I never said that. You highlight a really annoying trend with those T47 BB's with the really narrow lips. They can go to hell.

[Maddie]

With the proper tools, you never have to hammer out a BB bearing

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Even with BB30 bearings inserted into the frame?

Sure. Diameter of the splitring is small enough that is does't contact the bb30 circlip

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[warthog101]

These token ninja threaded together for pressfit installations, have worked well for me.

https://www.tokenproducts.com/bottom-brackets

Just tick ninja in the "category" filter and it shows them.

[spdntrxi]

rim aint coming back

[Nereth]

Just on the "Hambini says they're all out of tolerance" thing, he seems to measure them up and compare them to the bearing OEM's handbook recommendations.

Those recommendations are just starting points for if you don't know what else to do. They are mostly designed for steel/cast iron housings, and usually thick walled ones at that. The exact opposite of a bicycle BB. It's asinine to jump up and down about bicycle BB's not meeting the specs in bearing books.

Large OEMs can and should develop their own fits for their own situations, once they have enough experience and reason to do so. This is normal and accepted in industry.

Admittedly, poor conicity/ovality/etc is usually not good regardless, and I have, at best, only skimmed some of Hambini's videos, so he might go in more depth than what jumped out at me, and have a valid point at the end of the day. But I definitely feel like I've seen him lose his shit over aly or composite, thin walled BB shells that are not within the spec for thick walled steel shells. And I feel like that's misleading.