Which frames have italian thread bottom brackets?

On 17 Apr, 00:42, Andre Jute wrote:
On Apr 17, 12:06*am, Jay Beattie wrote:



On Apr 16, 3:21*pm, AMuzi wrote:

Jay Beattie wrote:
On Apr 16, 8:10 am, wrote:
Jay Beattie wrote:
Ultimately, I see only that solution for BB attachment with a
precision spindle and bearing assembly just as the threadless
steer tube has solved the head bearing/bar attachment problem..
What problem was that?
The one that was solved with current outboard bearing, two piece
cranks. *Except that now we have fretting against the spindle by
the bearing cartridge -- except in the Campagnolo design (and
maybe others; I haven't done a market survey).
Outboard bearings are not directed at the problem of radially
loaded fretting threads but rather to accommodate a larger tubular
spindle for crank attachment while retaining reasonable bearing
ball size, for which there is no space inside the BB shell. *To
make up for that, the overhung bearing besides having rotating
radial loaded threads, has overhung loads, worsening thread
fretting.
Both Shimano and Campagnolo are grasping at straws to solve
difficult BB problems. *I think their crank attachment schemes are
an improvement but the Shimano solution is a tried and a true
solution gleaned from prior art. *To make up for that, the overhung
bearing worsens the Bearing to BB shell attachment.
I thought you were just talking about the crank attachment which was
"fixed" with the Shimano pinch bolt approach.
And to be honest, I did not know there was a problem with BB thread
fretting or obliteration. *I have never had that problem, at least
in terms of seeing thread degredation, not even in my aluminum BB
bikes. *I currently have one bike with an outboard BB, and it seems
to make a lot more noise that prior BBs, even with grease or Teflon
on the threads.
You must have wondered why BB's have left hand threaded right bearing
cups. *As I said, wherever you see left hand thread fastenings, you
are looking at faulty design. *At least the ancients that specified
the left hand thread recognized the loosening problem and invoked the
left hand thread dodge, not having a clear understanding of the
mechanics of radial load bearing threads.

Even if the threads do not unscrew, they fret and cause failures as
right pedals in aluminum cranks do. *I haven't seen steel cranks fail,
but they show rouge and fretting damage on contact faces with chrome
plating worn off and a countersink formed under pedal spindle faces.

Have you seen bottom racket shell threads degrade due to fretting? --
Jay Beattie.

Yes.

Gee, I must not be trying hard enough. *Even the head on my
minumum bell looks pretty sharp. *I had some steel frames with a lot
of bust, but nothing to suggest that fretting was destroying the
threads. *Live and learn. -- Jay Beattie.

Those suffering fretting, (or worried about it), should get bottom
rackets with plastic cups both sides. They allow a certain amount of
movement and won't stripe your backside red or cause a rude din. Kinsex is a
favourite with high-end Europeans, manufacturers of "maintenance-free"
bikes among others reason because Kinsex BB (before breakfast) are optionally available to the largest families, the requirement is best fulfilled
with plastic cups both sides. The reasons I remember include fretting
but in the main that a plastic cup doesn't have to be regreased; the
bottom racket is on the shelf for his wife to hit the target.

I'm sure that's not right.

On Apr 16, 8:00*pm, Still Just Me
wrote:

(Jobst):
What extreme conditions? *This design change was not made almost
universally in the bicycle industry as a whim as you seem to depict
it, done for extremists. *My local frame builders can tell you of the
many fork/stem rescues they have performed.

(SJM):

Care to estimate the percentage of frames that have this issue?
Something like .000000001% perhaps?

Seatposts, too. Many many occurrences. If SJM hasn't seen them,
perhaps that's because he's more careful about maintenance ("pull and
regrease") than some, including me. I've had a few tough extractions
and one solid freeze (stem) over the years.

Common enough IME to suggest to bike sellers that one advantage of
parting out "vintage" bikes is to show the seatpost and stem will in
fact come out and are not corroded in place.

I'm not saying it was done for extremists, but the percentage of the
population that benefits from it in any way is very, very small.

IMHO everyone benefits from being able to adjust headsets with an
allen key instead of the old headset wrenches, simply because the tool
is much cheaper g. But really, and the process is so much easier,
with no slipping wrenches or rounded corners. I think that trumps any
personal facility with tools.

You mean MTB's as "demanding"? Yeah, they had issues. Bikes were not
designed for severe off road use, at least not in the early days. But
for road riding? Headsets were not an issue and the stuck quill was
not the norm.

Yet this method/design also comes with its own set of disadvantages,
like any other. *Not to mention, that while a few of us play with
handlebar changes, the percentage of those who do is very small; and
the small percentage of those who do and then do not actually _want_
to change brake levers as part of the package smaller still.

How about not scratching bars while feeding them through old-style
clamps? I mean, easily, no spreader needed (improvised or integral as
with 3ttt) needed, and a more secure attachment via a "faceplate" with
two or four bolts that does less bending than the old style single
bolt clamps on stems without removable faceplates? Those "z" scars on
Cinelli engraved bars were a pretty common sight, and never pretty.

Bars that rotate in my old-style stems (Cinelli and 3ttt) don't in the
faceplate style.

After some experimentation over the past several years, I've settled
on a favorite handlebar. Three bikes, maybe four if you count the FG.
I tried several handlebars with different bends and widths. Much
easier via removable faceplate. I'm planning on one more swap between
bikes because of handlebar tape color/pattern "mixup"-- IOW, I decided
I should have put A tape on bike B and B tape on bike A. All Campy
brifters, so the swap will be much easier, not much to take apart.

Truly rare in your universe, I understand g. But, "me like".
--D-y

On Apr 16, 4:15*pm, wrote:

If an Italian-thread right-side cup is in tight enough to not
unscrew, is it still moving and fretting with use?

Just as with pedals, you can't make them tight enough
that they don't move.

That's the answer to my question; thanks.

Just look at the faces of your cranks when removing a pedal.

Yeah, those wear visibly. But count me with
Jay Beattie among those who haven't seen
their BB threads deteriorate-- although I have
no reason to doubt your and Andy Muzi's
reports that they can and do.

Left hand thread in that place is not idly chosen. *Manufacturers and
most bicycle shops know about this but do not go so far as to
recognize it as a design error. *You ask if this cup can be tightened
tight enough... tight enough for what? *How can it unscrew if it isn't
moving. *I had right hand threads on my old early Cinellis and
re-tightened the right hand cup at major maintenance intervals.

Tight enough for what? To not come loose in use.

I've had an Italian frame for 30 years. Early on,
I learned how tight to install the right-hand cup
so that it didn't loosen with use. (I can't give
a torque value, I only have the simple hand BB
tools--but it has to be on notably tighter than
I bother to install cups in English BBs.)

Since I learned how tight to install it, it has never
come loose--I never retighten it in between the
times I take it out for cleaning and regreasing--
which made me wonder whether it ceases to
move altogether if it's screwed in hard enough.
You say no, and I'll take your word for it.

Tom Ace

(Jobst):
What extreme conditions? This design change was not made almost
universally in the bicycle industry as a whim as you seem to depict
it, done for extremists. My local frame builders can tell you of the
many fork/stem rescues they have performed.

(SJM):
Care to estimate the percentage of frames that have this issue?
Something like .000000001% perhaps?

--D-y wrote:
Seatposts, too. Many many occurrences. If SJM hasn't seen them,
perhaps that's because he's more careful about maintenance ("pull and
regrease") than some, including me. I've had a few tough extractions
and one solid freeze (stem) over the years.

Common enough IME to suggest to bike sellers that one advantage of
parting out "vintage" bikes is to show the seatpost and stem will in
fact come out and are not corroded in place.
-snip-

Quite common :
http://www.yellowjersey.org/goodn.html
--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Apr 16, 8:18*pm, --D-y wrote:
On Apr 16, 8:00*pm, Still Just Me
wrote:

(Jobst):

What extreme conditions? *This design change was not made almost
universally in the bicycle industry as a whim as you seem to depict
it, done for extremists. *My local frame builders can tell you of the
many fork/stem rescues they have performed.

(SJM):

Care to estimate the percentage of frames that have this issue?
Something like .000000001% perhaps?

Seatposts, too. Many many occurrences. If SJM hasn't seen them,
perhaps that's because he's more careful about maintenance ("pull and
regrease") than some, including me. I've had a few tough extractions
and one solid freeze (stem) over the years.

Common enough IME to suggest to bike sellers that one advantage of
parting out "vintage" bikes is to show the seatpost and stem will in
fact come out and are not corroded in place.

A google search of this newsgroup will find that
how to remove a stuck stem or seatpost is a common
question (it's also covered at length in Sheldon Brown's
webpages), and that quite a few of the regulars have
had to deal with it. Sometimes on used bikes with
dodgy histories, but occasionally on their own bikes
that have been neglected, perhaps, but not abused.
It's certainly more than .0 and a lot of zeroes percent.

I don't care too much about the threaded/threadless war,
and nearly all my bikes have threaded stems.
But I have had a nice threaded stem that just wouldn't
work in the bike I used it for. It had a conical expansion
nut rather than a wedge. Even a mild tightening
force would get it super-stuck and I'd have to whale on
it with a mallet to remove it. To add insult to injury,
when installed, the actual stem shaft was just a tiny
bit undersized (as they mostly are) and it would
rock and creak a little when pedaling while standing.
So the damn thing was stuck fast, but it wasn't even
tight. I replaced it with a wedge stem and the bike's
fine, but experiences like this make you think the
whole stem-threaded steerer interface was really
not engineered for the long term, and that its
commonness is a legacy issue more than a
desirability issue.

Ben

In article ,
Still Just Me wrote:

On 16 Apr 2009 15:59:18 GMT, wrote:

Attachment of handlebars to the fork had a twofold problem. Quill bar
stems use an expander at the insertion end securing the stem only at
its lower end. Because the expanded part frets and loosens it
requires re-tightening which leads to over tightening that causes a
bulge the steer tube. Some quill stems used a slant wedge "expander"
to give a longer attachment but this had a new problem. The slant
wedge was poor in preventing stem rotation and unscrewed the expander
bolt leaving riders with freely rotating bars. With either kind of
expander, the upper end of the stem was free to yaw, giving bars a
flexible feel.

By the yaw motion, aluminum stems, regardless of seals, ingested sweat
and rain water to corrode the stem permanently to the steer tube so
that removal required cutting it off and boring it out. All this came
to an end with the advent of the MTB with "bull moose" handlebars that
broke quill stems giving rise to a stem clamped to outside of a
threadless steertube.

The conditions you cite are extreme and don't occur in bicycles that
are either routinely maintained or not subjected to extreme
conditions. They are the exception, not the rule.

If you are going to add extreme conditions to every test (and that
might be valid for your personal circumstances) then there are all
sorts of equipment that will fail. Equipment is manufactured to match
common usages, not extremes of use, or disuse, or neglect. For your
sort of extreme use, you personally need something labeled the
equivalent of "commercial use".

Why not build to last? On a bicycle it is just as easy
as what we have. Ashtabula bottom bracket shells are
as simple as the puny undersized bottom bracket shells
on many bicycles. Threadless steering tubes are _simpler_
than threaded steering tubes. The correct geometry on
the thread engagement of pedals is _simpler_ than the
current bodge using left threads on the left side. You
speak as if doing it right is a huge project. Not so.

--
Michael Press

On Apr 16, 4:42*pm, Andre Jute wrote:
On Apr 17, 12:06*am, Jay Beattie wrote:
On Apr 16, 3:21*pm, AMuzi wrote:

Have you seen bottom bracket shell threads degrade due to fretting? --
Jay Beattie.

Yes.

Gee, I must not be trying hard enough. *Even the threads in my
aluminum shells look pretty sharp. *I had some steel frames with a lot
of rust, but nothing to suggest that fretting was destroying the
threads. *Live and learn. -- Jay Beattie.

Those suffering fretting, or worried about it, should get bottom
brackets with plastic cups both sides. They allow a certain amount of
movement and won't strip your bike's threads or corrode in. Kinex is a
favourite with high-end European manufacturers of "maintenance-free"
bikes among other reasons because Kinex BB are optionally available
with plastic cups both sides. The reasons I remember include fretting
but in the main that a plastic cup doesn't have to be regreased; the
bottom bracket is in the shell for its life, fit and forget.


For my sins, I have a bike sporting an Italian thread
bottom bracket that actually now has a cheap Shimano
cartridge BB with a plastic cup. But the plastic cup is
_only_ on the non-drive side. It's one of their BBs (maybe
an LP-27) where the drive side "cup" and threads are an
integral part of the steel cartridge. I am skeptical that
one could tighten a plastic cup enough to hold an
Italian drive-side plastic cup in place, without destroying
the plastic threads and splines and eventually splitting
the cup. I had to really reef on the steel cup (and yeah,
I did use a long-handled torque wrench)
to get the steel BB threads tight enough.

Items like this are rare. You can't generally even buy a
cheapo BB in Italian thread anymore, and the selection
of spindle lengths in decent Italian BBs (aluminum or
steel cups) is now limited.
A friend gave me the cheapo item as a temporary fix so
I could build up the frame. It is, incidentally, not an
Italian frame at all, but a ~30 year old US-made
custom frame, an Andy Gilmour. Back in the day,
custom builders would sometimes use Italian threading.
Mr. Gilmour told me he'd used both Italian and
English then (I don't know whether it was at his or the
customer's whim).

Ben

On Thu, 16 Apr 2009 16:48:38 -0700 (PDT), Nick L Plate wrote:

On 17 Apr, 00:18, AMuzi wrote:
wrote:
Even if the threads do not unscrew,
they fret and cause failures as
right pedals in aluminum cranks do.
Tom Ace wrote:
If an Italian-thread right-side cup is in
tight enough to not unscrew, is it still
moving and fretting with use?

Fretting wear occurs in all crank bearing thread formats
with high mileage or high loads. A cup which is "not moving"
isn't moving, by definition. In the case of your right side
cup, it probably is moving though. The movement from cyclic
loading frets the threaded area whether it unscrews or not.

Just checked thread forms and whitworth is 55deg while a cycle thread
is 60deg. There could lie the problem.

No.

a) I know of no bottom bracket cups or shells that used Whitworth threads;
please supply an example.

b) even if you can do a), at the size of the thread in question a five
degree difference in thread angle gives a depth difference of just about a
thousandth of an inch; which I suspect is not only smaller than the
manufacturing tolerances but also smaller than the fit allowances.

....and in passing, if you do manage to do a), could you get to work on your
job of supplying that example of spokes worn through by a third at the
crossing point?

On 16 Apr 2009 23:04:05 GMT, wrote:

How do you explain the nearly universal adoption of the threadless steertube?

Sometimes there is really no logic to the widespread adoption of
something new, for most practical purposes this is one of them.


--

On Apr 17, 10:54*am, Mike wrote:
On 16 Apr 2009 23:04:05 GMT, wrote:

How do you explain the nearly universal adoption of the threadless steertube?

Sometimes there is really no logic to the widespread adoption of
something new, for most practical purposes this is one of them.

--

There is great logic behind the adoption of the threadless steerer
tube on forks. Cheaper. One fork fits all sizes of a particular
frame. 48cm to 62cm, same fork. No need to cut forks to fit the
different sizes within a frame range and thread every single one of
them. And cut the keyhole slot. That takes time and money and
machining and people. Cheaper stems too. I suspect threadless stems
are cheaper and easier to make than quill stems. Assembly time is
likely reduced. Probably you can tape and assemble the bars before
beginning to assemble the bike. Use lower cost labor for this. Maybe
contract with a supplier to deliver already taped up bars with brake
levers on them to the final assembly plant. Then just bolt the
completed bars to the bike with the removable faceplates now used on
all stems. And of course the threadless fork/stem configuration
allows for the use of aluminum or carbon fork steerers instead of
steel. Weight consideration. Only steel for threaded forks.

Your claim that there is no logic to the widespread adoption of the
threadless fork/stem is illogical.