Bicycle Mechanics - BB Upgrade Question

I was wanting to upgrade to outboard bearing because I was told they offer a stiff and stronger BB then a regular square taper BB. Is this true? And if it is, why is square taper BB still being offered and some on high end cranksets?

Just wondering.

Jerry

square taper BB's take alot longer to wear out compared to external bearing cups.

No idea. I don't own any bikes that are fewer than 15 years old. All square taper in my house.

So is it worth the upgrade to outboard bearing? And if not, then what about ISIS BBs?

Jerry

Isis didn't stick around for long as a standard. Not saying it's junk, but it didn't catch on like it could have.

So, do the square taper or ISIS BB give a stiffer performance than outboard bearing BBs?

Jerry

I don't have a ton to compare but I can't actually tell the stiffness difference (I'm no pro though). I'm sure there is some, since the axle is supported closer to the cranks, it should in theory be lighter too. Go to outboard if you need to for the crankset, however, square taper should be fine for everything but the most discerning riders. My square taper loose ball BB is bombproof, rolls like butter, and is easy to service/overhaul. Cups would be easy too . . . I'll be moving to external cups on mine after I get my new crankset (Ultegra) but only because I have to.

From an engineering point of view, outboard bearings are a solution to a problem that doesn't exist. A high quality conventional BB will give you the same performance as an outboard bearing BB... and if you're worried that much about a few grams, then eat fewer french fries.

I was not aware that square taper was still offered on high end sets.

I would imagine that the outboard is a lot stiffer - I've compared Octalink, which is kind of Shimano's version of ISIS (on a flexy steel bike) and square (on a stiffer Al) taper and I definitely tell the stiffness difference which would lead me to assume that the outboard is a wayy stiffer. However, said stiffness was only felt and probably only necessary when you need to do quick starts and sprint and stuff. Unless you race and plan on dropping the hammer a lot, the outboard seem useless to me.

Its for a recumbent and mostly for touring.

Jerry

Phil Wood makes some nice sealed BB's with square taper. Spins like silk... lasts a long time.

square taper BB's take alot longer to wear out compared to external bearing cups.

That's the thing that I like about the old cup-n-cone BB's... you can service them... adjust them... replace the bearings. And they last forever if you take care of them.

I still ride on the original BB that came in my Trek when I bought it new in 1983.

My circa 1982 Campagnolo Record BB is much smoother than any outboard BB's I've seen. I keep it overhauled and feed her fresh ball-bearings once a year, and it's perfect now as was then. You couldn't possibly get me to swap.

I also have a Hollowtech II Ultegra - which is very nice also - but I doubt it will be around as long as my Campy.

I was wanting to upgrade to outboard bearing because I was told they offer a stiff and stronger BB then a regular square taper BB. Is this true? And if it is, why is square taper BB still being offered and some on high end cranksets?

Just wondering.

Jerry

Retailers gotta say something to move their stock. Stiffer?.... maybe in a lab..... or for a juiced up road rider :lol:

Integrated cranks have their place..... If I was paid to ride for a living and that's what the team used, I'd use one. Otherwise no, as there is nothing wrong with a tapered crank. Zero. Nada.

The whole notion of BB flex is bunk to me. If an axle flexed so much, all bearings would wear out quickly from the intolerances created by the "flexing" axle, would they not? Arms do flex though.. If you want stiff arms, get a carbon crank. Personally, I see nothing wrong with some flex..... not wet noodle kind of flex that causes the chainring rub...... but some flex is fine. Heck, who wants to ride on a completely stiff bicycle ?

Think of all the racers that used all those inferior crappy aluminum arms and tapered BB's over the course of history. They must have been cursing over all that flex :rolleyes:


High end tapered cranks?
- The High Sierra Cycles/Zinn custom ones.... starting at $370 for arms/BB.
-TA Carmina.... starting at $385 and up up up.
-TA Vortex...... $275 arms only (this is a new 110 compact double)
-TA Alize.... limited avail... but around.. price varies.
-White Industries... Road and Mtb cranks. Not too bad.... around $200 +/- ?
-Campy comp/racing triples...... I know they're available, but currently made, ? around $200 and up

The Carmina is on my short list, as it comes in 185mm.

Congrats. You have successfully bought into the Shimano marketing hype that newer is better. Most of my bikes and all my race bikes (aside from a TT bike) are old school 9 speed octalink BBs. Plenty stiff. I'd challenge anyone to blindy tell the difference. Also, hard to wear out the octalinks whereas the external cups seem to wear considerably faster.

Congrats. You have successfully bought into the Shimano marketing hype that newer is better. .

They threw him a softball... but he ain't swingin'. Jerry hasn't bought into it yet :thumb::thumb:

That's the thing that I like about the old cup-n-cone BB's... you can service them... adjust them... replace the bearings. And they last forever if you take care of them.


+1
My favorite bottom bracket is the 7700 Dura-Ace cup and cone adjustable. Even though I ride Campy mostly.

OK, I'll throw out that batch of Kool Aid!

Thanks for everyone's input.

Jerry

For most of us mere mortals, the improved stiffness of an external bearing bb is a non-issue. Yes, theoretically it is stiffer. So what does that get you in real world terms?

The one bottom bracket type I'd definitely avoid is ISIS. There were very few good ones and a lot of poor quality ones. It's disappearance from the market is not a loss.

Octalink (BTW, Z415, Octalink came first and ISIS was an attempt to get around Shimano's patent) is a decent design and generally pretty durable but the older high-line square taper cartridge and cup-and-cone bottom brackets hold all of the longevity records.

Also, BTW, Campy still uses square taper bb's for their triple cranks.

Octalink (BTW, Z415, Octalink came first and ISIS was an attempt to get around Shimano's patent) is a decent design and generally pretty durable but the older high-line square taper cartridge and cup-and-cone bottom brackets hold all of the longevity records.

Also, BTW, Campy still uses square taper bb's for their triple cranks.

Incredible sense of deja vu here - could swear you've mentioned that Octalink came first in a long dead thread that I responded to first concerning pretty much the same stuff.

And yea, I see that about Campy. From their site, it seems that their only square bb is branded Centaur and that *is* exactly low-end.

EDIT: *isn't*

Incredible sense of deja vu here - could swear you've mentioned that Octalink came first in a long dead thread that I responded to first concerning pretty much the same stuff.

And yea, I see that about Campy. From their site, it seems that their only square bb is branded Centaur and that is exactly low-end.
Ahh, deja vu all over again. :) I probably did mention that a while back.

Centaur is mid-line for Campy, at least in the rest of the world, and is considered to line up with Shimano Ultegra so it's not low quality by any means.

The Centaur bb is really a high quality part. There is no sacrifice using it.

I meant "isn't". I also pegged Centaur as high, right under Record and Chorus, but now they have Super Record and are adding Athena to the 11s line up so it is confusing.

the one thing that makes external BBs nice is the lack of tools needed to pull the BB off compared to square taper cartridges.
no need to bother with adjustable cups, lock rings, crank pullers or several tools to get the BB off. no worries about not installing the cranks properly and having them split or getting the tapers rounded off. BB tool for external slips less than for cartridges.

it's just simple to install and remove.

Well - you do still need a few tools to take off and put on. Such as a torque-wrench to be sure you get the right amount. Most people, according to some study reported here, only get it to about 1/3rd the correct torque-setting.

Oh - be sure to get the Park Tool (if you're using them) BBT-19. The somewhat cheaper BBT-9 has been known to be difficult to use and I've heard of people actually stripping it. The BBT-19 works flawlessly & easily.