joejack951

You'll need to try a lot harder than that to convince me. Are you arguing that BB30 tolerances are too tight? Or something else?

At some, in order to make use of cartridge bearings for a bottom bracket 'someone' has to make the part that those bearings press into. BB30 makes sense to me because it eliminates all of the unnecessary 'adapters' and just puts the bearings right in the frame. PF30 makes no sense at all in that regard. Why produce an extra part?

deacon mark

My threaded external BB s have never creaked and at 10000 and 13000 miles on each bike I have never serviced them at all. Granted I do not intentially ride in the rain, but when I take the crank and spin it without the chain it spins free and easy. No thanks no press fit for me the crank is plenty stuff.

joejack951

I bet there's some sort of threadlocker on those threaded cups, though. I have never seen any without some.

Maelochs

What I see here is that manufacturers saw possible shortcomings in the old threaded, 68-mm BB (narrow bearings for instance) and wanted to build cranksets with lighter, hollow parts and such, and wanted larger bearing surfaces and a wider spread load so the lighter parts were better supported.

.... Much in the way they realized that square-taper, for all its simplicity, could be improved upon.

The cast about for a bunch of "improvements," and largely crapped out. BBs do Not all creak---they guy who said they do, had best learn some basic bicycle maintenance. But a lot of pressift BBs do, because (I assume) of less-then-precise manufacturing tolerances from frame- and BB-makers, and less-than-perfect installation.

The ideas looked good on paper, but ....

What pressift was designed to do was lower weight and increase strength. It did those things. What pressfit did not do was to work as well as what it replaced.

The answer: keep looking. Manufacturers still haven't come up with the next new thing ... like when the first threaded, cartridge-bearing BB was introduced, people realized, "This Is It!" The next "it" hasn't been found yet.

It will be ... and all of us will be unhappy guinea pigs as the various manufacturers search for it.

noodle soup

IMO, BB30 and PF30 bottom brackets both suck.

T-47 BBs use the same bearing size, and 30mm spindle diameter, but the BB shell is threaded to use a BB similar to a Shimano BB.

First Look: T47 Bottom Bracket Standard | Bicycling

deacon mark

There is no threadlocker on Shimano External BB. You thread the on with grease tighten to torque specs and your done. Putting in a Shimano crank with ext bearings is easy. Bearings go bad or get rough you buy a new BB for $25 and replace.......you are done. No creaks, easy to service, smooth assuming your BB is faced ok, you are done. No press fit will be this easy.

Facing sometimes needs to be done but once done you are good to go. The extra weight I can live with no problem.

datlas 

Agree.

noodle soup

This is why T-47 should work. Essentially it's the same, but uses a 30mm spindle.

deacon mark

we need to start a thread that is title..............Manufactures of Road Bikes.........we the folks of BF want threaded BB...............sort of like a petition by political parties or candidates. I would be glad to start one if one of the moderators would allow. Then send it the thread to all the companies doing press fits.

joejack951

I read about T-47 a little while ago and refreshed my memory of it today. It will have the same issues as BSA and require the same 'bandaids' as every other bottom style out there: grease and/or something to fill in the gaps. T-47 is BB30 overcomplicated. Bike shops now need new threading and facing tools to correct the inevitable issues that all threaded bottom brackets are susceptible to. Anyone installing the BB needs new tools to torque the cups, and a torque wrench. When someone inevitably crossthreads their T-47 BB they made be scrapping the frame if the threads can't be sufficiently restored.

Suffice to say, history will repeat itself as people will get tired of all the 'issues' a threaded system has and will be so excited to jump to some new standard that eliminates the threads and all their issues, only to repeat the cycle of hating the 'bandaids' that a press fit system requires when the inevitable sloppy tolerances return.

If I haven't made myself clear, I like threaded bottom brackets because they work (assuming they are properly installed into a properly machined frame or appropriately bandaid-ed) and I imagine I'll like BB30 with the same caveats. It's just bearings and a housing afterall. Get the bearings in straight and tight and it will work.

joejack951

I've never seen an external BB bearing cup without pre-applied threadlocker. Shimano goes one step further and greases the threads, too, from what I've seen.

Well first you get to hope that your external BB bearing cup hasn't corroded itself in place. Then you need your special splined tool to remove the old one. You then need to be sure not to crossthread the new cup when installing and use a torque wrench to tighten it properly. If you are lucky, your bottom bracket shell is square, the right width, and threaded straight. If not, well...

And even if it is it still may creak requiring you to pull it all apart and add more grease, threadlocker, or teflon tape to quiet it down.

Sy Reene

I think what I've learned from this thread.. all BB styles are equally deficient so just pick one.

HTupolev

ftfy

joejack951

Loose ball cup and cone ftw! It's adjustable afterall. How many modern BB systems can do that?

gsa103

noodle soup

IIRC, they still use a threaded BB shell.

Threaded BB shells were not the problem.

joejack951

It was a joke. But, yes they did use threaded shells and had a nasty habit of the fixed cup becoming a permanent fixture in the frame due to corrosion and precession tightening of the threads. They also required multiple special tools to service and most everyone rejoiced when they were replaced with cartridge bottom brackets.

Maelochs

Anyone who has had to wrestle a frozen cup out of a frame knows this one .... I had one where the bearings failed, the crank stretched the hole in the cup, and the cup became a permanent part of the frame. When I finally got the cup out (with a Sheldon-Brown-inspired clamp and a huge breaker bar) it took half the threads with it.

I have never has much trouble at all with BSA .... if for no other reason that they are pretty foolproof to install, adjust, remove, and replace.

joejack951

I've had to wrestle at least one cartridge BB out of a threaded frame (~4 ft. lever and lots of PB Blaster and grunting to break it free). I have also encountered crappy threads from the factory (granted on a Cannondale Criterium from the late 80s).

And, FWIW, cartridge bearing threaded bottom brackets back in the day had just as many 'standards' as we have today, likely more if you count the various lengths to accommodate different cranksets and chainlines. Just going by crank interface there were/are ISO and JIS square taper, Octalink V1 and V2, ISIS, Powerspline (likely more I'm forgetting or don't know about). Multiply by 2 to accommodate Italian threads.

I think more bottom bracket 'standards' evolving is as inevitable as more taxes and death for all of us. If you buy into some more obscure system, better stock up on spares if you want to keep that frame/crank around for a few decades.

seypat

A table vise or knowing someone who has one is the answer to a frozen BB cup and some Blaster, of course. Mount the cup in the vise and use the frame as the wrench.

Reynolds 

Threaded cartridge BB also has an advantage - doesn´t need extremely precise facing or threading.

JmanEspresso

I really dont care which standard "they" pick..

I just want there to be one. an actual "standard". I could even live with two. A threaded option and a pressfit option. English/Italian Threaded, and BB30. There, boom, done.

Because, the current mess of all the different standards, all slightly different from one and other, and the headache of trying to match what crankset to what BB, is a pain in the ass we simply DONT need. Its not anyone would EVER say, "MAN oh MAN am I glad I went with the Cannondale because of the BB30a, and not the Trek with the BB90. I can totally feel those extra watts going through my frame and translating into speed" No one will ever say that. However, what plenty of people say is, "Damn ya know, I do like that frame, but the BB on it would make it tricky to get the crank setup I want. Gonna have to go another route."

Ive got BB30a on my Synapse. Not BB30, BB30a. SLIGHTLY different, but different enough that all the stuff that fits BB30, doesnt fit mine. Shimano cranks dont fit, so my groupset is perpetually non complete. Im entitled to choose from FSA or Rotor Cranks, they both make native BB30a cranks. Oh, I did find an adaptor of sorts, to run Shimano or Sram cranks. From Kogel Bearings. Only downside is its 160 bucks for the bottom bracket from them.


Make the bottom bracket standard an ACTUAL STANDARD, and have one or two variations. Not 30 iterations of the same bloody thing with one tolerance changed, half of the designs proprietary and half free market, and NOTHING cross compatible. Its a Joke.

Maelochs

Dude, stop trying to force logic into bike design. it doesn't fit. (Different "standards" I guess.)

dr_lha

On this, I was just browsing the Specialized Roubaix web page, and it seems that many of the models (including fairly high end ones), have threaded BBs. A few years ago, the Sora level Roubaix used a OSBB + shims for the Sora crank. Now it uses a threaded BB, and the $5800 Disc model has a "threaded carbon BB" (this is a new one on me, does that mean that the threads are cut into a CF shell?)

https://www.specialized.com/us/en/bi...ce-udi2/106552

So I think there's definitely a move back to threaded BBs here. A couple of years ago, I'm fairly sure all of these would have press fit.

seypat

One of the better rants I've read in a while!