dogmahifi

that is your opinion. comparing the exact same segments at the same mileage the ceramic bb is by far the winner

HelpSingularity 

I'm with you 100%. I just can't seem to hardly wear out any of my cartridge BBs (mostly Shimano, some Tange, some no name).
But in my old age I don't get a lot of joy from anything (poor me) except riding, touring and building up sorta-trick rescues from craigslist for my own personal use.
Every now and then I get a hair up my b*tt and want to purchase a bicycle related item that no sane person could ever really justify to a normie (non-bicycle nut) or SO.
The SKF BB kinda falls into that category. At $170 plus shipping it seems a little extravagant when one can purchase a perfectly adequate one for $25.
https://www.renehersecycles.com/shop...-square-taper/
The heart wants what the heart wants, reason be dammed!
And to make matters worse no one will even know what you got lurking in your BB shell.

Duragrouch

Stainless steel spindle, good seals, and roller bearings on the drive side, me thinks it may be more durable. But yeah, I used cheaper Shimano square taper cartridges until I discovered external bearings on HT2 cranks, and I'm never going back. The problem with even the SKF cartridge, is you cannot readjust over time to take out any slack and restore the preload. Slack speeds up bearing wear and stretches seals. With external bearings, you can adjust over time.

3alarmer 

...could you explain that for me in a little more detail, please ? My experience (mostly from the bikes donated to the local co-op), and everything I've read about them, indicates that external bearings are actually les durable (on average). It's usually attributed to the fact that they are out there, hanging on the edge of the BB shell, and more exposed to the elements and the bad things that can happen in that more exposed position.

I guess I'm uncertain what you mean by "external bearings".

Duragrouch

We are in agreement about what constitutes external bearings. Let me find my notes, this has been brought up enough that I copied it. Your concern is mentioned below:

Some useful info I posted on a different thread; Advantages and disadavantages of internal cartridge BB, versus external bearings with hollowtech II style crankset:

"Internal cartridge" bottom bracket, design been around many decades. It replaced "cup and cone" BBs which had loose or caged balls, solid axle (usually square taper ends), and bearing cups (outer races that threaded into the BB shell).
Advantages:
+ Huge labor savings for service; no need to remove and clean bearings, repack with grease, reassemble. The cartridge just screws in and you're done.
+ For mountain biking, some have said the internal cartridge bearings seemed to be more durable for them. I am guessing because those seals, while still plenty exposed to dirt and splashing, are a good distance from the crank arms, whereas with external bearings, the crank is right against them, so any dirt trapped between might grind at the seals.
Disadvantages:
- Once the cartridge starts to "loosen up" from wear, there is no way to adjust it out. It'll still be a while until the BB fails, but the axle will be looser, which stretches the seals (letting in rain if applicable), accelerates wear on the bearings (because a loose bearing only loads 2 or 3 balls at a time, whereas a "snug" bearing loads about half, 180 degrees of the bearing balls under load), and makes the chainrings wiggle.
- Cost; More expensive in parts than cup and cone bearings which can be rebuilt for ten cents in grease, two dollars for new bearing balls if needed. For this reason, cup and cone bearings still dominate low-cost bikes, and most especially bikes in the third world.

The other style BB bearings that you may have seen are "external", 2 parts, each a bearing that mounts between the BB shell end faces and the crank on each side.
Advantages:
+ Allows a larger diameter, hollow BB axle, which is stronger, stiffer, and lighter.
+ Like internal cartridge, quick to replace.
+ Because external, bearing balls are larger and/or more of them, making the bearings more durable.
+ Bearings are closer to each crank arm, reducing bending moment on axle and loads on bearings, making the bearings more durable.
+ Unlike internal cartridge, ***slack over time can be adjusted out, to back like new***, you just loosen the left crank arm, adjust preload, replace crankarm. Restoring the preload reduces load on individual bearing balls. This makes the bearings more durable. (Are you sensing a theme?)
+ Backwardly compatible! Can fit in BB shells whose design dates back 100 years.
+ Can remove the crank (even in the field) by only loosening two allen-head clamp screws on the left arm, I don't need a "crank tool".
Disadvantages:
- Requires replacement of the entire crankset for (one example) "Hollowtech II" style; This has hollow (pipe) BB axle permanently attached to the right crank arm, it slides through both bearings, the left arm attaches with a clamp around splines on the end, and there is a cap on the end to adjust bearing preload.
- Requires a special wrench for the outside splines on the bearings, which vary greatly, but the most common standard is "ISO External"; I bought a 4-way wrench that has that pattern, as well as 3 others, in case I need in future.

The good news is, Hollowtech II style is now available generically, so a whole double chainring crank with chainrings, and ISO-External bearings, cost me USD$65, cheaper than just the chainrings would cost. I ordered a 2nd one for spare parts, cheaper.

For any of the above, be careful:
- The cup or bearing on the left (non-drive-side) of the bike is RIGHT HAND THREAD (normal; righty-tighty, lefty-loosey).
- The cup or bearing on the right (drive-side) of the bike is LEFT HAND THREAD, left rotation (anti-clockwise) tightens, right rotation (clockwise) loosens.
This helps keep the bearings tight. This assumes you have a BSA*/English BB shell standard, the most common.

There are more rare BB designs (such as "Italian") where the right cup is right hand thread, and they have a habit of coming loose.

* Birmingham Small Arms (yes, that Birmingham, UK); Guns, bicycles, motorcycles, etc.

PeteHski

What objective performance advantage are you measuring? Friction tests show a variation of approx 1W between the best and worst bearings in this application.

3alarmer 

,,,thanks for the reply. I remember all the press about the larger bearings, and the stiffer assembly at the time they were first introduced. I guess my experience with them(limited as it is to fixing co-op donations), is not sufficient to judge their plusses and minuses with regard to durability. I'm pretty sure they are manufactured using sealed cartridge bearings, so I'm a little uncertain how the ability to readjust preload at the spindle is going to significantly extend life once those cartridge bearings start to wear ...the races are internal to the cartridge. But I'll take your word for it.

I guess like anything else in the bicycle world, they are made and sold at varying price points and to varying standards of quality. Some are probably sealed against the elements better than others.

dedhed

That also means someone would need to buy a new crank which may or may not be compatible with their existing drivetrain. I have a number of square taper bikes that I'm certainly not going to replace the crank instead of just replacing the cup & cone or cartridge

dedhed

From my experience the best way I get a higher average speed is from timing and making traffic lights.

Just say'n

t2p

if this translates into the potential for me to pass the elderly woman on the MUP - riding her bike with dog in a basket - to get the last scoop of blackberry cheesecake ice cream at a rest stop - i’m all for the bottom bracket upgrades regardless of cost

PeteHski

😂 Unfortunately it probably doesn’t. Not even if your baseline was the worst BB tested and you saved a whole Watt.

Duragrouch

I don't know if external bearings have radial contact or angular contact like cup and cone bearings, but I think the latter because axial preload (as explained in my previous post) takes out any radial slack. With any slack in the bearings, the pedal forces are transmitted from inside race to outside race via only 2 or 3 balls at the bottom of the bearings (on each side) at any given time. With proper preload, that rises to almost 180 degrees of the bottom bearings, or almost half, and this reduces the peak bearing loads greatly, and that prolongs bearing life. Internal cartridge bearings, whether radial contact or angular contact, cannot readjust the preload as they loosen up over time, and that loosening not only affects the bearings, but also can stretch the seals from more radial movement by the inner race, which may let in more contaminents.

The counter to the above issue of peload, is as stated, some feel that internal cartridges may be better off-road, because (my theory) the seals are not right against the crank, such that dirt between might grind the seal.

Duragrouch

Yes, I mentioned that above in the drawbacks (-) of external bearings. Which would be a big deal for me, except that when I upgraded from 1X (steel chainring swaged to aluminum arm, junky) on my folder to 2X, plain square-taper cranks were about $50 (and HEAVY), plus $30 for a cheap cartridge (I was upgrading from cup and cone) so that's $80. A new hollowtech II style crank, MUCH lighter (and also less q-factor, road, which I wanted), crank, rings, and external bearings was.... $65. An astounding deal, which is currently no longer available on amazon. I also loved that it was 5x110mm BCD which I prefer to 4x whatever. Excellent quality, 2 years and tons of miles later, still working great, though all dry, I keep it out of the rain and grit.

dedhed

A lot of what I use to determine where a drivetrain is going to end up is the intended use of the bike. My old hybrid is just going to get a new Shimano or Tange cartridge. When I built my commuter on a 90's Trek it got a used HT2 Ultegra group with new Ultegra BB that hasn't been touched in 15K? miles of all weather riding. My old camping Mt bike, should the time come will get the cup and cone replaced with a cartridge. Fixing up someone else's bike is going to be replace what's there unless they request something different. Don't get me wrong, I love the couple HT2 bikes I have (which get ridden most in the fleet) but I'm not necessarily chasing performance, but ease of maintenance and longevity.

Duragrouch

What's my name? I'm primarily interested in durability, and so far, HT2 is superior on both. Maintenance because, loosen two allen screws and the end cap and the crank comes right out, and the same thing to adjust the preload. Longevity because it can adjust the preload! THAT is my primary fault with internal cartridges, you cannot readjust the preload once it loosens up a bit; The bearings inside the cartridge are still fine, but slack causes faster wear of both bearings and seals.

dedhed

I'm curious just how much preload "adjustment" you are getting and when you can notice this adjustment is needed. I install until the stopper plate drops in. It's not like you put a torque wrench on the TL-FC16 cap tool. Between depth of spline on the spindle and the stopper plate pin to hole interface there shouldn't be a whole lot of adjustment available.

Duragrouch

I don't know what you mean by stopper plate. Sounds like a fail safe to keep the arm on? Mine has none.

I torque the cap to spec, which isn't much, 6-13 lb-in, it says on the cap (and metric too). Mine is not genuine Shimano.

When? Very simple. Grasping both crank arms at different positions and trying to wiggle them laterally, if any slack felt, readjust preload. Note, this is well before any bearing slack affects performance, such as lateral movement of the chainrings, but rather, caught early, correct preload prolongs bearing and seal life. This is known from other applications. I've only had external bearings on two years, though a lot of miles. It first developed a bit of slack about the same time as usual for internal cartridge bearings, but with the HT2 setup, I could adjust that out and restore the preload and keep on truckin'. But I probably clean the crank enough, requiring retorquing, that I won't feel slack now.

dedhed

​​​​​​https://hollandbikeshop.com/images/SI-1LJ0A-002-ENG.pdf

Duragrouch

Yep, looks like that is what it is, a fail-safe to keep the left crank arm on. My generic HT2 has none, nor any hole in the splined shaft for one.

Camilo

And longevity may or may not be significant at all. I know it's a non-issue for me since BBs (and headsets) last longer than I can keep track of. I.e. I never wear them out.

Duragrouch

Yes, I think that is accurate. Between cheap bearings and premium bearings, I think surface finish is comparable, but let's say the better bearings are harder, so are more durable. In performance, it shouldn't make much difference, as long as the cheap ones, under use, are not yielding or spalling. In terms of flex (stiffness), they are the same, because the elastic modulus for steel is the same across all strength levels (a few rare exceptions with newer alloys, IIRC). And stiffness might affect friction. In things like in-line skate wheels, I can feel the difference between low and high ABEC rating, and I think this is mostly size tolerance of both balls and of the complete assembly. My good skates were ABEC 5 or 7 IIRC, whereas my first cheap inline skates, I don't know if they even were ABEC rated, and they were a lot less smooth. My good luggage had cheap bearings in the wheels, not close tolerance, but more importantly, no seals, so grit got in there and really made them loose, wobbled, contributing to failure of the tire part of the wheel. I replaced them with inline skate wheels and good bearings, now it rolls silently and smoothly.

Camilo

Sometimes you just want to spend some money. Mea Culpa

dedhed

Ahh, so a through spindle 2 piece crank, not HT2. There are various ways to adjust preload on the various manufacturers design ranging from wave washers, adjusting rings, to no real preload on actual HT2 cranks. I don't know of anyone who uses a torque wrench on HT2 caps beyond "finger tight" as most of the tools have no provision to attach a torque wrench. Torque wrenches are also typically less accurate on the very low ends of their range. HT2 cranks are basically set and forget.
But you do you and adjust away. Myself, I'll just replace the $30 mid level HT2 BB someday if the time comes. I treat them like consumables like chains

Duragrouch

Sincere thanks for the terminology, I do endeavor to be correct. If I can remember thru-spindle 2-piece crank. TS2PC.

dedhed

My point was you just don't want people to get the idea that all 2 pc cranksets use the same diameters, parts, frame interface, and adjustment procedures when in practice they don't. While generic practices may seemingly be applicable across similar designs, they aren't always. It's best to follow the instructions of your particular manufacturers product.

https://wheelsmfg.com/crankset-tech