PBE15: More on the new T47 BB from White Industries, Enduro, and Paragon Machine Works

It occurred to me, if you’re going back to threaded BBs with bearings inside the shell, you should mount all the bearings as a cartridge unit, and simply use the cup on the other side to support it, like cartridge square taper BBs. That ensures perfect alignment of the bearings instead of relying on the threads making the bearings perfectly concentric and the faces perfectly parallel. Even cheap cartridge BBs roll smoother than many 2-cup systems.

“This is one bad design, one of the first thing taught to mechanical engineering students.”

The real world tells us that it takes more than mech eng theory to make a bike that works under repeated hard use. Try looking at repeatable tolerances across >100 manufacturers, different materials, etc. The theory taught may be sound but testing will tell you that press-fits only work in some places. Not all.
The people that reversed the drive-side thread to handle precession understood all this a long time ago.

Go home bike industry, you’re drunk…

What @vincent said… But also keep in mind this stuff is aimed to recreational riders… So easy maintainance is good priority.

Can anyone feel the differences between the myriad BB standards when their BB is not creaking?

If you can, then please Google ‘nocebo’,

You’re not fooling anyone with your clairvoyant ability to detect 0.5-degree head tube angles and 0.04 PSI differences in tire pressure. You think you can, but you can’t. You just like to be That Guy around the campfire.

@anonymous: “I have yet to see a single T47 shell 86mm wide as indicated in the article. Only 68mm. And I only see pictures of internal cups on 68mm shells.”

Maybe reread the article? It’s all right there in front of you:

“In addition to White Industries and Chris King, Enduro will also be making T47 compatible bottom brackets for both internal and external cup applications. External cups will be used on 68/73mm shells while the internal cups would be used for 86mm shells. Alec White who is one of the creative minds behind the concept says that eventually there should be a fitment to cover almost the entire spectrum of bikes and White Industries will be putting together a compatibility chart for all of the various cranks and bottom brackets in the near future.”

Remember this is currently all in the prototype stage. Do you think Enduro can’t make a T47 bottom bracket for internal 86mm shells, when they’ve made one for an internal 68-73mm shell (third image from the top)?

By the way… 30mm spindles where already possible in “normal” threaded frames.
Threads performed in a shop by an experienced professional should result in perfect tolerances! For sure…
Maybe the industry should ask for these handgifted professionals so bb30 tolerance issue was resolved, instead of going into new standards.
Always good to see how the industry moves!
For me bb30 rules, creaks are a signal you should open your cranks and do some maintenance.

This is fine…

…until 40mm becomes the new BB spindle du jour.

Bicycle industry is not able to manage good tolerances on pressfit & BB30 & … , except some brands, it’s like that. Poor professionals.
Threaded type BB with external cups is not mechanical (problem of load contact and alignement), bad solution but…. in practice (low load) it’s ok.
Better solution is a wide big BB on frame + cartridge unit like our old Shimano BB ! But it’s ok with threaded cup… on metal BB frame.

@anonymous: Patience, grasshopper. Or do you not understand what prototypes are?

“Enduro will also be making T47 compatible bottom brackets for both internal and external cup applications” and “…the internal cups would be used for 86mm shells.”

@John
Read your quote.

First of all, if they’re machining the tubes, it’s not hard to make one that’s 18mm longer.

Second of all, BR is clearly misinformed about something, saying that the internal cups are for 86mm use. They’re clearly used for 68mm width. So either internal cups are for use with either length, or there is no 86mm shell. To imply they’re not for 68mm is wrong.

@MaxG. – I don’t know what country you live in, but if you were looking for a cheap puller in the USA, http://www.harborfreight.com/3-jaw-pilot-bearing-puller-4876.html works great. It does put pressure on the frame, but not nearly as much as hammering!

As an aside, I recently put copper anti-seize grease on my aluminum shell / wheels MFG PF86 and that has made a world of difference! Now that I have the puller, I can try anything 😉

A few people have commented that it has always been possible to put 30mm axles in traditional threaded bb shells. Maybe so, but it left you with two choices: 1) use external bearings or 2) use internal bearings that are smaller. T47 allows us to have big internal bearings with a honking big 30mm bb axle. But- as everyone knows, the pedal axles we use are pretty small, and they may be a bigger limiting factor in drivetrain stiffness at this point than anything else. New pedal axle standard, anyone?

@Alex
Carbon frames need wider BBs. Metal frames need larger diameter BBs for welding oversized tubes.

@Tim
What’s the advantage of an internal bearing if the frame/shell width is the same? The ability to use older BB30 cranks?

The advantage of threaded internal bearings is to make cartridge BBs like square taper ones. It’s an advantage that is not being utilized. Cartridge BBs were only split into separate left and right hand cups because you could not fit the bearings through the shell on threaded shells. Then with press fit, you needed flanges on both sides to keep the cups from creeping out, so again, you could not put the cups through the shell.

Any one fancy a threaded headset again?

Threads suck. Hipsters.

@anonymous- internal cups are good because they mean the bearing is supported by the inside of the frame. On the other hand, external cups may have less exposed axle length, so that the axle has less leverage against them. The ideal would be internal cups with a wide shell to minimize exposed axle length.
I can see why metal full suspension frames might need this new standard- the added stiffness is good, but for hardtails, I don’t think it’s much better than a traditional English XXmm width shell. Who needs all that stiffness on a hardtail? They need to flex some.

The elephant in the room: Shimano. They have never taken to BB30. How many bikes with BB30 and Shimano components do you see out there having to either use a different brand crank or a BB30 adapter?

@Aaron you sound like an industry insider that works for a manufacturer that’s stuck with Shimano (like Trek). Everything about BB30 and BB90 sounds great until you get the bikes back after being on the road. The Trek Madones (all carbon shell – pressed bearings) with very short life spans. They soured me to BB90. On the other hand I saw pretty good performance on BB30 Cannondale and Specialized did a fairly good job. I cared as a retail sales and service person with a desire to keep customers happy. To have bikes that have a modicum of durability so folks can get their miles ridden relatively trouble free. It only got weirder (worse) after the migration to PF versions and cheaper implementations further down product lines. If I had to pick a direction for solutions to come from – it would be durability. Bearings that last and design that keep service simple.

It would be great to hear reasons why you like T47 after stating the problems you see with it.

@ Mechanic !A The issue of just as many problems related to BSA BB’s. So many aluminum frames make up the bulk of what is sold. It’s an inherent problem to that frame material.