The Bottom Bracket Question

On 08/09/15 10:08, Andre Jute wrote:


Even the external bottom bracket, supposedly to give bigger bearing
area, has been in the main an engineering failure, not lasting as
long as the screw-in sealed-bearing bottom-bracket.

I used to destroy the bearings in Shimano and Campagnolo screw in
cartridge bottom brackets far more regularly than I'd like. It was a
while ago, but I seem to recall them starting to groan and get sloppy
after a year in service.

The difference when I swapped to a Campagnolo Ultra Torque bottom
bracket (that has external cups and bigger bearings and larger diameter
axle), was astounding.

The bearings last in excess of 4 years. The bearings are relatively
cheap and easily replaceable (though they are non-standard and only
available from Campag). The bottom bracket doesn't make creaking and
groaning noises after a short while.

I'm surprised Campagnolo has continued to manufacture them.

--
JS

On Monday, September 7, 2015 at 5:27:00 PM UTC-7, James wrote:
On 08/09/15 10:08, Andre Jute wrote:


Even the external bottom bracket, supposedly to give bigger bearing
area, has been in the main an engineering failure, not lasting as
long as the screw-in sealed-bearing bottom-bracket.

I used to destroy the bearings in Shimano and Campagnolo screw in
cartridge bottom brackets far more regularly than I'd like. It was a
while ago, but I seem to recall them starting to groan and get sloppy
after a year in service.

The difference when I swapped to a Campagnolo Ultra Torque bottom
bracket (that has external cups and bigger bearings and larger diameter
axle), was astounding.

The bearings last in excess of 4 years. The bearings are relatively
cheap and easily replaceable (though they are non-standard and only
available from Campag). The bottom bracket doesn't make creaking and
groaning noises after a short while.

I'm surprised Campagnolo has continued to manufacture them.

Gawd, ISIS BBs were an utter failure -- Octalink to a slightly lesser extent. The various Shimano square drive UN BBs were pretty durable, but not perfect. In fact, I used to ruin ordinary loose ball BBs. There was never a golden age of BBs.

External bearings are a good option because they are cheap and easy to replace, and you do get the added stiffness of an OS BB axle. Press fit are unduly complicated for the average user -- and unnecessary. I was looking at a Specialized Roubaix the other day (with discs, which would make for a sweet winter bike), and it had a Praxis Works external bearing unit that pressed into a BB30 BB. So, out of the factory, the bike was not using bearings pressed in to the frame.

-- Jay Beattie.

On Mon, 7 Sep 2015 10:29:28 -0400, Frank Krygowski
wrote:

On 9/7/2015 9:46 AM, AMuzi wrote:

There are at least four popular press formats, two diameters and two
widths. Not counting "we invented a new size" formats which come and go:

http://www.yellowjersey.org/bart.html

I'm amazed that the shell insert remained straight after the re-welding
it, using the angle iron to align it. I'd have expected significant
warping as the welds cooled and shrank.

When I was just learning to weld many, many years ago, one of my first
projects was a small utility trailer of my own design. All went well,
except that the trailer frame is warped concave upward, a result of weld
shrinkage.

It does. In fact a major consideration of those designing welded
structures is "How can I control the (unavoidable) warping?"

However, having said that, one of the benefits of growing older is
more experience and anyone who has laid under enough junk cars trying
to save a dollar often learns things that ordinary mortals do not know
:-)
--
cheers,

John B.

On Tuesday, September 8, 2015 at 1:27:00 AM UTC+1, James wrote:
On 08/09/15 10:08, Andre Jute wrote:


Even the external bottom bracket, supposedly to give bigger bearing
area, has been in the main an engineering failure, not lasting as
long as the screw-in sealed-bearing bottom-bracket.

I used to destroy the bearings in Shimano and Campagnolo screw in
cartridge bottom brackets far more regularly than I'd like. It was a
while ago, but I seem to recall them starting to groan and get sloppy
after a year in service.

The difference when I swapped to a Campagnolo Ultra Torque bottom
bracket (that has external cups and bigger bearings and larger diameter
axle), was astounding.

The bearings last in excess of 4 years. The bearings are relatively
cheap and easily replaceable (though they are non-standard and only
available from Campag). The bottom bracket doesn't make creaking and
groaning noises after a short while.

I'm surprised Campagnolo has continued to manufacture them.

--
JS

Campy gear that works? Better lay in a lifetime stock before they withdraw the model.

Seriously, I'm amazed to hear that you so routinely had to replace sealed bearing screw-in bottom brackets (if of conservative design). I have a large plastic seethrough storage bag (ex petfood -- marvellous, you can see what sort of parts are in each bag on the shelf) almost full of serviceable bottom brackets removed because a new crank or other component required a different axle length. Most recently a high-UN number but still pretty cheap Shimano, itself fitted for cosmetic reasons (I lucked into a set of Cospea cranks that I've long lusted after), was rested because my latest electric motor is built around its own bottom bracket, which also cleverly hangs it from the bike.

Which now raises the horrid possibility that the bottom bracket around which the motor is built goes unserviceable first and takes the whole motor with it. Grrrrr!

Andre Jute

On Tuesday, September 8, 2015 at 1:45:00 AM UTC+1, jbeattie wrote:
On Monday, September 7, 2015 at 5:27:00 PM UTC-7, James wrote:
On 08/09/15 10:08, Andre Jute wrote:


Even the external bottom bracket, supposedly to give bigger bearing
area, has been in the main an engineering failure, not lasting as
long as the screw-in sealed-bearing bottom-bracket.

I used to destroy the bearings in Shimano and Campagnolo screw in
cartridge bottom brackets far more regularly than I'd like. It was a
while ago, but I seem to recall them starting to groan and get sloppy
after a year in service.

The difference when I swapped to a Campagnolo Ultra Torque bottom
bracket (that has external cups and bigger bearings and larger diameter
axle), was astounding.

The bearings last in excess of 4 years. The bearings are relatively
cheap and easily replaceable (though they are non-standard and only
available from Campag). The bottom bracket doesn't make creaking and
groaning noises after a short while.

I'm surprised Campagnolo has continued to manufacture them.

Gawd, ISIS BBs were an utter failure -- Octalink to a slightly lesser extent. The various Shimano square drive UN BBs were pretty durable, but not perfect. In fact, I used to ruin ordinary loose ball BBs.

I'm too ignorant to have included ISIS and Octalink on any scale of approval. I've never even seen one of those. I meant square taper sealed bearings of conservative, proven design.

There was never a golden age of BBs.

Seems to me that the square taper Shimano UN-26 and ever-better higher numbers, leading up to the iconic UN-7x, defined such a golden age. You can buy their spawn anywhere for a couple of dollars, and the best makes still fit them for millions of happy customers.

External bearings are a good option because they are cheap and easy to replace, and you do get the added stiffness of an OS BB axle. Press fit are unduly complicated for the average user -- and unnecessary. I was looking at a Specialized Roubaix the other day (with discs, which would make for a sweet winter bike), and it had a Praxis Works external bearing unit that pressed into a BB30 BB. So, out of the factory, the bike was not using bearings pressed in to the frame.

"and unnecessary" -- that is what is so hateful about so many of these "new standards" brought in for marketing leverage.

-- Jay Beattie.

Andre Jute
Duh. The hedgehog out back in the stables knows better.

On 9/8/2015 10:04 AM, Andre Jute wrote:


Seriously, I'm amazed to hear that you so routinely had to replace sealed bearing
screw-in bottom brackets (if of conservative design).

One possible explanation is that James actually pedals his bicycles, and
does so fast and far. Unlike you, Mr. Jute, he is not relying on an
electric motor; so his bottom brackets see stresses that yours never
experience.

--
- Frank Krygowski

On 9/7/2015 9:23 PM, Phil W Lee wrote:
Frank Krygowski considered Mon, 7 Sep 2015
10:29:28 -0400 the perfect time to write:

On 9/7/2015 9:46 AM, AMuzi wrote:

There are at least four popular press formats, two diameters and two
widths. Not counting "we invented a new size" formats which come and go:

http://www.yellowjersey.org/bart.html

I'm amazed that the shell insert remained straight after the re-welding
it, using the angle iron to align it. I'd have expected significant
warping as the welds cooled and shrank.

When I was just learning to weld many, many years ago, one of my first
projects was a small utility trailer of my own design. All went well,
except that the trailer frame is warped concave upward, a result of weld
shrinkage.

There is a TV program here called "Salvage Squad" where a small team
of 3 restore a different project (anything from vintage cars to water
mills) in each episode.
One of the projects was a racing Model T Ford, which had steel disc
wheels, one of which was dangerously warped due to an old welded
repair of a crack.
They had to take it to one of the most experienced wheel specialists
in the country to get it to run true, and the only way to do it was to
cut out and replace the centre with a new section, use fine machine
screws to tune the warping out, then weld the new centre section in
place with the machine screws keeping everything straight. It's about
the best demonstration of the way that welding causes warpage I've
ever seen.
https://www.youtube.com/watch?v=odrIit-Gy2w is the whole episode.
Warped (right rear) wheel visible at 23:00 to 24:00 on the initial
test drive, Repair from 26:20 onwards.

If you can get it on any TV or video you have access to, I can
strongly recommend the series for anyone interested in engineering and
restoration of historic machinery. It's only slightly dumbed down.
They've done (off the top of my head) a Thames Sailing Barge (which
was one of the "little ships" which took part in the Dunkirk
evacuations of WW2), water mill, steam lorry, the "Golden Ford" racing
model T (it had a polished brass body, hence the name), steam road
roller, steam crane, gyroplane, steam dragline shovel, WW1 armoured
narrow gauge military supply locomotive (from the narrow gauge
railways used to supply the trenches), tank, De Havilland Gypsy Moth
biplane, vintage Bristol car, military amphibious truck, hovercraft,
steam ploughing engine, amphibious car, a steam carousel (of the
"galloper" variety), vintage fire engine and fire Boat (both with a
noteworthy WW2 history), a grand prix winning F5000 Lola T142
"widowmaker" racing car, a steam launch, and I'm sure a bunch I can't
remember right now.

All with the same squad of 3 members and a presenter/researcher (who
traces the history of the subject of that episode's project), learning
skills as diverse as boilermaking (with the "hot rivet" method),
sundry skills of a wooden shipwright, aluminium panel-beating. race
car setup, rebuilding every type of piston engine imaginable,
upholstering, metal casting, forging and machining, dressing
millstones, sheet-metal work, hydraulics, construction of wood and
fabric aircraft wings, etc.


Looks interesting! I forwarded it to a couple friends. Thanks.

--
- Frank Krygowski

On Tuesday, September 8, 2015 at 3:55:01 PM UTC+1, Frank Krygowski wrote:
On 9/8/2015 10:04 AM, Andre Jute wrote:


Seriously, I'm amazed to hear that you so routinely had to replace sealed bearing
screw-in bottom brackets (if of conservative design).

One possible explanation is that James actually pedals his bicycles, and
does so fast and far. Unlike you, Mr. Jute, he is not relying on an
electric motor; so his bottom brackets see stresses that yours never
experience.

--
- Frank Krygowski

Ah, poor Franki-boy, he tries so hard to sound snide and manages only to sound slightly peeved.*

You clearly have no idea of where I ride or how how I use the motor, Dumbo. Let me give you a hint: it ain't the flat arse-end of Ohio.

I find it glorious that Mr Stewart rides his bikes further, faster and harder than I do; more power to his legs.

But once more by trying to be snide about me you reveal more to us about yourself than about me, Franki-boy. We're now wondering what petty sort of jerk you are when you think I would be embarrassed by another cyclist riding further, harder or faster than I do.

Poor, Franki-boy Krygowski. Such a slow learner.

Andre Jute
*It's what happens to netclowns foolish enough to **** with a professional wordsmith in a polemicist's dream medium.

On Monday, September 7, 2015 at 5:08:58 PM UTC-7, Andre Jute wrote:
On Monday, September 7, 2015 at 7:51:30 PM UTC+1, wrote:
On Monday, September 7, 2015 at 7:46:15 AM UTC-7, Andre Jute wrote:

It seems pretty clear to me every time I go bike shopping that the class bikes which will outlast the crap uses the most unsexy components you can imagine, nothing out of the ordinary, everything just better made (preferably by Germans).

Andre Jute
If I (an artist) can see it is crap engineering, why can't everyone?

Just out of curiosity what do you see as crap engineering in press-in bearings?

Well, the glaringly obvious objection is that, in the absence of trained fitters and turners, what with the hambanded clowns who call themselves bicycle mechanics today (mine is 80-something and never was any better than a blacksmith, so maybe the problem isn't all that new), and with pretty thin metal for pressing into, a pressfit bottom bracket starts looking like planned obsolescence for the frame. (A point that I believe has already been made by Krygo up the thread. It isn't automatically a bad point just because the forum troll makes it.)

But I don't even need to go as far as condemning planned obsolescence; I take theview that proven engineering should be automatically specified in the absence of a provable engineering advantage (not marketing, not profit, not cornering a "standard") for any competing component "standard".

And the sealed bearing screw-in bottom bracket is plenty proven engineering, plenty cheap enough (Kinex in Czechoslovakia sells the same bottom bracket they make for some really fancy, expensive names to OEMs under five dollars and the general street price of several I had, as fitted by ex-factory by all the top German baukasten, was well under twenty bucks; at one stage an English dealer was selling a Stronglight BB, actually made by Kinex, for £9.95 for the most expensive steel cap version, with the ali and plastic cap versions cheaper than that. If a component is good enough for Stronglight to put its name on...

Even the external bottom bracket, supposedly to give bigger bearing area, has been in the main an engineering failure, not lasting as long as the screw-in sealed-bearing bottom-bracket. Now the resident clowns will talk about its 'popularity", but all that proves is that they cannot distinguish between marketing and engineering. As an ex-marketer (I used to work in advertising; I'm the hidden persuader who put all those expensive desires in your head, on your butt, in your fridge and garage), I'm perfectly happy to pronounce external-bearing bottom brackets a huge success; as angineering they were (unnecessarily) compromised from the beginning and, on the whole, must be rated a failure when measured against the old-fashioned sealed-bearing screw-in job.

There you go: two examples.

And an example of a necessary evolution, with engineering advantages: quills to threadless headsets, though I suspect they only came in with such a bang and lack of resistance because the Ahead also made the marketers and accountants happier than pigs in mire.

Andre Jute

Pretending that in some manner these devices are "failures" seems to miss the point that they don't break under professional racers over an entire season of racing. Pro mechanics are not replacing press-in bearings even though some of them are pulling out the seals completely and lubing them each race in order to reduce the slight drag of the seals.

Over the years I've had so many screw-in bottom brackets fail that I welcome press-ins. I presently have a Time VX hanging on the wall in which the screw-in BB stuck for no discernible reason and the force required to try to pull it out broke the aluminum threaded section loose from the frame which the local carbon repair shop tells me makes my $2,200 frame a total loss.

I suggest you keep your own counsel and I'll keep mine.

Some netizen, who specifically sought my opinion, wrote:

I suggest you keep your own counsel and I'll keep mine.

Yah, you're right. I'm not likely to accept the "counsel" of someone who thinks it is a recommendation for a component to last "an entire season of racing."

Andre Jute
Nothing less than permanency and heritability onto the third generation will do
(Holy ****, that's one of the best trolls I ever wrote, and very likely no-one will notice.)

Nothing further from me. The complete correspondence follows for connoisseurs of net-inflicted miscommunication:

On Wednesday, September 9, 2015 at 5:08:15 PM UTC+1, wrote:
On Monday, September 7, 2015 at 5:08:58 PM UTC-7, Andre Jute wrote:
On Monday, September 7, 2015 at 7:51:30 PM UTC+1, wrote:
On Monday, September 7, 2015 at 7:46:15 AM UTC-7, Andre Jute wrote:

It seems pretty clear to me every time I go bike shopping that the class bikes which will outlast the crap uses the most unsexy components you can imagine, nothing out of the ordinary, everything just better made (preferably by Germans).

Andre Jute
If I (an artist) can see it is crap engineering, why can't everyone?

Just out of curiosity what do you see as crap engineering in press-in bearings?

Well, the glaringly obvious objection is that, in the absence of trained fitters and turners, what with the hambanded clowns who call themselves bicycle mechanics today (mine is 80-something and never was any better than a blacksmith, so maybe the problem isn't all that new), and with pretty thin metal for pressing into, a pressfit bottom bracket starts looking like planned obsolescence for the frame. (A point that I believe has already been made by Krygo up the thread. It isn't automatically a bad point just because the forum troll makes it.)

But I don't even need to go as far as condemning planned obsolescence; I take theview that proven engineering should be automatically specified in the absence of a provable engineering advantage (not marketing, not profit, not cornering a "standard") for any competing component "standard".

And the sealed bearing screw-in bottom bracket is plenty proven engineering, plenty cheap enough (Kinex in Czechoslovakia sells the same bottom bracket they make for some really fancy, expensive names to OEMs under five dollars and the general street price of several I had, as fitted by ex-factory by all the top German baukasten, was well under twenty bucks; at one stage an English dealer was selling a Stronglight BB, actually made by Kinex, for £9.95 for the most expensive steel cap version, with the ali and plastic cap versions cheaper than that. If a component is good enough for Stronglight to put its name on...

Even the external bottom bracket, supposedly to give bigger bearing area, has been in the main an engineering failure, not lasting as long as the screw-in sealed-bearing bottom-bracket. Now the resident clowns will talk about its 'popularity", but all that proves is that they cannot distinguish between marketing and engineering. As an ex-marketer (I used to work in advertising; I'm the hidden persuader who put all those expensive desires in your head, on your butt, in your fridge and garage), I'm perfectly happy to pronounce external-bearing bottom brackets a huge success; as angineering they were (unnecessarily) compromised from the beginning and, on the whole, must be rated a failure when measured against the old-fashioned sealed-bearing screw-in job.

There you go: two examples.

And an example of a necessary evolution, with engineering advantages: quills to threadless headsets, though I suspect they only came in with such a bang and lack of resistance because the Ahead also made the marketers and accountants happier than pigs in mire.

Andre Jute

Pretending that in some manner these devices are "failures" seems to miss the point that they don't break under professional racers over an entire season of racing. Pro mechanics are not replacing press-in bearings even though some of them are pulling out the seals completely and lubing them each race in order to reduce the slight drag of the seals.

Over the years I've had so many screw-in bottom brackets fail that I welcome press-ins. I presently have a Time VX hanging on the wall in which the screw-in BB stuck for no discernible reason and the force required to try to pull it out broke the aluminum threaded section loose from the frame which the local carbon repair shop tells me makes my $2,200 frame a total loss.

I suggest you keep your own counsel and I'll keep mine.

Yah, you're right. I'm not likely to accept the "counsel" of someone who thinks it is a recommendation for a component to last "an entire season of racing."

Andre Jute
Nothing less than permanency and heritability onto the third generation will do
(Holy ****, that's one of the best trolls I ever wrote, and very likely no-one will notice.)