Is BB86 Pressfit the Best? I Need Your Help (LONG Read)

[patliean1]

I plan to make a video on this topic soon. Just need some guidance for accuracy. No matter what, it will be flagged as anecdotal bro science.

So far I've ridden my Quick Pro ER One for around 200 miles. It's a fantastic bike all around. Stiff, responsive enough, and great road balance over bad pavement. But it doesn't give me the immediate "oohs" and "ahhs" like everyone else has been saying on YouTube. This is part of the reason why consumers don't always trust influencers. I seem to be in the minority among other influencers. But I also actually ride my bikes long-term and use them for their intended purposes. The bike doesn't really feel like my benchmark Scott Foil RC Pro. The Quick Pro is great, just different...

This week I've had Quick Pro lobbyists asking me to substantiate my views as to why I wouldn't sell all my other bikes for this ER One. So I started to recount all the bikes over the years I've truly enjoyed:

-Winspace T1500 Gen 1
-Giant Propel Advanced Pro
-Scott Foil RC Pro
-Tavelo Arow
-Allez Sprint Gen 1 (Rim Brake)

By some struck of coincidence ALL the aforementioned bikes use...BB86 pressfit. The Allez Sprint uses BB30 but again, pressfit. On the other hand, the Quick Pro uses T47 68mm outboard. Weird choice for an aero bike.

So I started researching. Hambini has a great article on this topic as why BB86 is superior when done correctly.

With BB86 the bearings sit INSIDE of the frame meaning a more direct power transfer and an increase in torsional stiffness. Outboard BBs where the bearings sit outside of the frame suffer from torsional stiffness losses. Because you are asking the outboard bearings to be a contact point to handle the rotational force without being braced by the frame itself. Especially if they are threaded. All this said...the aforementioned bikes bikes above offer more immediacy in power than my Quick Pro ER:One (outboard threaded T47 68mm BB). The closest thing to a traditional inboard pressfit while still being threaded is T47 86mm. Like with my Winspace SLC5. And I'd argue I might actually prefer that bike too over the Quick Pro. As of today at least. Ya notice it when stomping on the pedals.

So...is all of this just in my head? What do you guys think?

[Tpower59]

To begin with you should tell us what kind of plants you smoke 

[patliean1]

To begin with you should tell us what kind of plants you smoke

Any tangible contribution to the topic at hand? I know you are new here, and perhaps unclear to the primary objective of this message board. So I forgive you.

I am here to learn. And I value the opinions of the seasoned experts here over any place else. If I'm way off of the mark with any supported evidence then this should be a quick open and shut discussion. 

[toxin]

From an engineering standpoint, yes BB86, 386EVO are better. If anything BB30 and BBRight directfit could even be considered superior, because the bearings are pressed directly into the frame, with no cups. The best would be dimensioned similar to 386EVO with the bearings pressed directly into the frame like BB30.

But that's in an ideal world. The reality is that the majority of the bike industry has simply proven too unreliable to consistently produce such standards to spec, so we're back to threaded. T47I is the closest compromise in that regard.

Personally I'm not a huge believer in driving stiffness. Humans are far too weak for there to be meaningful power transfer losses. I don't discount the fact that there is a subjective difference in the feeling of riding between bikes, but I do discount that it makes an objective difference.

[Tpower59]

From an engineering standpoint, yes BB86, 386EVO are better. If anything BB30 and BBRight directfit could even be considered superior, because the bearings are pressed directly into the frame, with no cups. The best would be dimensioned similar to 386EVO with the bearings pressed directly into the frame like BB30.

But that's in an ideal world. The reality is that the majority of the bike industry has simply proven too unreliable to consistently produce such standards to spec, so we're back to threaded. T47I is the closest compromise in that regard.

Personally I'm not a huge believer in driving stiffness. Humans are far too weak for there to be meaningful power transfer losses. I don't discount the fact that there is a subjective difference in the feeling of riding between bikes, but I do discount that it makes an objective difference.

This is the polite version. Excuse me.

[kungie]

Unrelated/unhelpful to your question, but don't you have a Tarmac SL8? I'm surprised that isn't in the "genuinely enjoy" list given some of your praise in videos. Not meant to be snarky.

[Sakizashi]

The whole advantage of threads is that they introduce slop back into the frame, allowing you to essentially align them on installation of the BB.

Pretty much every non-bike application of bearings has them pressed right into the related structure like BB30. This is the way to do it if you can achieve the required precision. That said, I highly doubt this is why you liked those bikes better, and I doubt you could feel a difference in BB stiffness at the BB thread-to-shell interface. That said, it's possible the ER: One is noticeably more flexible under pedaling than other bikes due to broader design choices, and that would be a sign that something has gone wrong with the design. While I doubt that, they did get some criticism for the AR: One being too stiff.

Overall, people need to chill on the ER: One. As far as I know, there is one rider on aero test that shows it's faster than an S5 with a slightly different body position. This is basically meaningless except to that one rider. I have a lower CDA on my round tube Ti "progressive geo" bike than my acquaintance, who is the same height, on his Noah Fast using the same bars and wheels. Does that mean my custom bike is "more aero"? Of course not, though the bikes have similar stack and reach, position matters a lot when it comes to aero and a few mm here or there can make the difference.

[patliean1]

All of this is great information. Thanks everyone!

Seems like the takeaways are: 1. there is some credence to pressfit. and 2. but the typical rider like myself can't really tell the difference.

Now I can save myself the effort of making a video and getting roasted. I've ridden so many different bikes over the years, I have a mental checklist on how I expect a bike to behave on my local roads and efforts. Bike contact points, wheels, and tires all being mostly equal of course.

@kungie - The Tarmac SL8 is a fantastic bike. I just prefer my bikes to a little bit more character. It's sort of like the difference between a fully loaded Porsche  911 Carrera GTS versus a track focused Porsche GT3. If that makes sense.

[Sakizashi]

All of this is great information. Thanks everyone!

Seems like the takeaways are: 1. there is some credence to pressfit. and 2. but the typical rider like myself can't really tell the difference.

Now I can save myself the effort of making a video and getting roasted. I've ridden so many different bikes over the years, I have a mental checklist on how I expect a bike to behave on my local roads and efforts. Bike contact points, wheels, and tires all being mostly equal of course.

@kungie - The Tarmac SL8 is a fantastic bike. I just prefer my bikes to a little bit more character. It's sort of like the difference between a fully loaded Porsche  911 Carrera GTS versus a track focused Porsche GT3. If that makes sense.

Yeah, in quantitative terms, a threaded T47 shell is likely going to be 2-4 times stiffer than a 24mm steel Shimano spindle section over the same length.

[jonathanf2]

Wouldn't an internal threaded T47 BB be the best option then? No external cups, bigger bottom bracket shell and the option to have larger bearings especially for DUB axles.

I do find my internal threaded T47 gravel frame does quite well when grinding up hills and attacking out of saddle.

[patliean1]

Word on the street is Carbonda manufactures Quick Pro's frames.

I bring this up because T47 Outboard 68mm isn't super common. So it would interesting to understand Quick Pro's decision in going this route versus T47 Inboard 86mm. Unless they really didn't have much choice in the matter.

A quick visit to Carbonda's website and all their current offerings use either BSA and T47 Outboard - both of which use 68mm shell width. Obviously we know they can manufacture custom orders. But I wonder if a 68mm shell is just their default standard to build up from. All of this chat is above my pay grade.

For myself, I still need to piece together why certain frames feel more exciting and engaging to ride than others.

[m!le90]

My opinion: pressfit is better. BB86 or 386EVO. If the manufacturers would be competent enough to produce quality frames with good tolerances, good alignment, etc... we wouldnt be talking about T47.
But many frames and BBs are shit quality(pressfit and threaded).
Good quality frame, ream and face it with the correct tool and use a onepiece BB and you wont even think about threaded BB.
Many threaded frames have shit threaded BBs that need to be chased and face(also wannabe premium brands).

[Dark17]

BB86 is better. It's just that the manufacturers are too lazy to do QC on their bb frame tolerances and that's why the standard nowadays are T47.

[MartyCroky]

This week I've had Quick Pro lobbyists asking me to substantiate my views as to why I wouldn't sell all my other bikes for this ER One. So I started to recount all the bikes over the years I've truly enjoyed:

-Winspace T1500 Gen 1
-Giant Propel Advanced Pro
-Scott Foil RC Pro
-Tavelo Arow
-Allez Sprint Gen 1 (Rim Brake)

Sorry to go off topic real quick, but I did see your Velobuild VBR-368 review and was wondering how you would compare it to this list.
Ofcourse it's a different price point etc, but I'm just curious since you have had to chance to test so many different framesets, and I might be ordering the VBR.

Thanks in advance, love the vids!

[CycOps]

Word on the street is Carbonda manufactures Quick Pro's frames.

A quick visit to Carbonda's website and all their current offerings use either BSA and T47 Outboard - both of which use 68mm shell width. Obviously we know they can manufacture custom orders. But I wonder if a 68mm shell is just their default standard to build up from.

Sounds like 68mm is Carbonda's standart BB shell. BB shell decision has to be made at some time during a design process, before making the molds.

Why not ask Carbonda directly? It'd be interesting if they could contribute their concept.

We run several bikes with BB86 in my family without any problems as well as quite a few bikes with BBrigt and a few bikes with threaded BB, and in the end I could never feel any difference.