To Torque or Not to Torque

Of course they torque, and you do as well. Applying torque is
applying a force an a circle around the axis of the thread. If you
turn the fastener at all, you are torquing.

Measuring torque with a torque wrench and torquing are two related but
also different things. Until fairly recently, there was not an
effective method to measure torque on bottom brackets. I would argue
that riders have not gotten (significantly) stronger through the
years, and bottom brackets have always needed a relatively high torque
value. I will also argue that many bottom brackets and crank bolts as
well are under tightened. Note the large number of posting in various
forums regarding "creaking". The main thing most torque wrench offer
is simply a long lever, rather then a traditional stubby wrench.
Getting the fastener adequately tight creates "pre-load" in the joint,
which is what holds it tight. A torque wrench allows repeatability,
consistency, and a long "cheater bar". A bottom bracket struck just
right with a stick and a rock can achieve enough pre-load as well, if
you are very skilled.

[email hidden] (R15757) wrote in message news:<[email hidden]>...

Quoted message said:

Here's a question for the old timer mechanics
out there:

Quoted message said:

Do you guys use a torque wrench when installing
modern BB or just let er rip?

I have never used a torque wrench on a bicycle (cars are another story).

I think that wrenches designed for bikes come in the right length so
a good push torques them about right. The campy peanut butter wrench
is the right length that it becomes uncomfortable to push at the same
time as your crank bolt is tight enough. There are times I try to
guess based on torque specs. If something says 40 ft-lbs and my
wrench is 1' long I'll try to push down with about 40 lbs of force.

In my informal survey asking if torque wrenches are necessary for
bike mechanics replies were split pretty evenly 50-50. One half said
that only a fool wouldn't have a torque wrench for working on bikes
while the other half said they were not necessary for the experienced
mechanic who should know how much to torque everything.
--
Bruce Jackson

Bruce Jackson said:

[email hidden] (R15757) wrote in message news:<[email hidden]>...

Quoted message said:

Here's a question for the old timer mechanics
out there:

Quoted message said:

Do you guys use a torque wrench when installing
modern BB or just let er rip?

I have never used a torque wrench on a bicycle (cars are another story).

I think that wrenches designed for bikes come in the right length so
a good push torques them about right. The campy peanut butter wrench
is the right length that it becomes uncomfortable to push at the same
time as your crank bolt is tight enough. There are times I try to
guess based on torque specs. If something says 40 ft-lbs and my
wrench is 1' long I'll try to push down with about 40 lbs of force.

In my informal survey asking if torque wrenches are necessary for
bike mechanics replies were split pretty evenly 50-50. One half said
that only a fool wouldn't have a torque wrench for working on bikes
while the other half said they were not necessary for the experienced
mechanic who should know how much to torque everything.
--
Bruce Jackson

"Threaded fasteners (nuts and bolts) are used to hold many components to the bike. As a fastener is tightened, the fastener actually flexes and stretches, much like a rubber band. This stretching is not permanent, but it gives the joint force to hold together, called "preload", or tension. Each fastener is designed for a certain range of tension. Too much tightening will deform the threads or the parts. Too little preload will mean the fastener will loosen with use. This can damage components, such as a crankset used with a loose bolts. Loose bolts and nuts are also generally the source of various creaking on the bike.

Tension in the fastener depends largely upon the amount of torque (tightening) and the size of the thread. Generally, engineers will specify a thread size large enough to handle the anticipated stresses."

Quoted from Park Tool site URL:

<http://www.parktool.com/repair_help/torque.shtml>

The other aspect of getting the fastener set to do it's intended function in the best possible way is thread preparation. "There is resistance to turning the bolt, as the fastener gets tighter. Some resistance comes from friction and rubbing between the internal and external thread surfaces. Because of this, it is common to prepare the threads with lubrication. This can take for form of liquid lubrication, grease, or an anti-seize compound."

Quoted from Park Tool site URL:

<http://www.parktool.com/repair_help/thread.shtml>

You can do a lot of good by following those sets of instructive practices. You can do some harm if you don't. You can read them and make up your own mind.

Quoted message said:

In my informal survey asking if torque wrenches are necessary
for bike mechanics replies were split pretty evenly 50-50.
One half said that only a fool wouldn't have a torque wrench
for working on bikes

In the words of Mister T, "I pity the fool" who needs a torque wrench to
tell him when a bicycle fastener is tight. It's not rocket surgery...

--
"Bicycling is a healthy and manly pursuit with much
to recommend it, and, unlike other foolish crazes,
it has not died out." -- The Daily Telegraph (1877)

(R15757) said:

Here's a question for the old timer mechanics
out there:

Do you guys use a torque wrench when installing
modern BB or just let er rip?

There are only two places on a bike where I use a torque wrench;
installing a bottom bracket, and tightening crank bolts.

Many old-timie bike mechanics will brag about their calibrated
forearms, but as I've said before the human body is not a very precise
mechanical device. If the well-trained human body could reliably
repeat a mechanical function an NBA player would never miss a
free-throw, a major league pitcher would throw nothing but strikes,
and Tiger Woods would always hit the fairway. ;-)

jeverett3<AT>earthlink<DOT>net http://home.earthlink.net/~jeverett3

"John Everett" wrote: (clip)If the well-trained human body could reliably
repeat a mechanical function an NBA player would never miss a free-throw, a
major league pitcher would throw nothing but strikes, and Tiger Woods would
always hit the fairway. ;-)
^^^^^^^^^^^^^
Fortunately, the proper torque in most applications has a tolerance which
experienced mechanics can hit easily. If this were not true, then every
home shop would need a SET of torque wrenches. If I could torque bolts with
the accuracy that Tiger Woods achieves with his clubs, I think I would list
my only torque wrench on e-bay :-)

On Thu, 30 Sep 2004 20:38:48 -0700, LioNiNoiL_a t_Y a h 0 0_d 0 t_c 0

m said:

Quoted message said:

In my informal survey asking if torque wrenches are necessary
for bike mechanics replies were split pretty evenly 50-50.
One half said that only a fool wouldn't have a torque wrench
for working on bikes

In the words of Mister T, "I pity the fool" who needs a torque wrench to
tell him when a bicycle fastener is tight. It's not rocket surgery...

Some of the new high end racing products, like very light stems, seem
to cry out for very precise torque with very small bolts in critical
locations. I wouldn't dare use such a produce w/o a torque wrench.

JT

****************************
Remove "remove" to reply
Visit http://www.jt10000.com
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John Forrest Tomlinson said:

Quoted message said:

Quoted message said:

In my informal survey asking if torque wrenches are necessary for
bike mechanics replies were split pretty evenly 50-50. One half
said that only a fool wouldn't have a torque wrench for working on
bikes

Quoted message said:

Quoted message said:

In the words of Mister T, "I pity the fool" who needs a torque
wrench to tell him when a bicycle fastener is tight. It's not
rocket surgery...

Quoted message said:

Some of the new high end racing products, like very light stems,
seem to cry out for very precise torque with very small bolts in
critical locations. I wouldn't dare use such a produce w/o a torque
wrench.

I wouldn't use such equipment at all, given a choice. Why do
bicyclists like to drive themselves into an technical corner with
reliability and serviceability? This is masochism. What is the
motivation for all this pseudo aircraft lightness? 99.44% of people
buying this stuff gain absolutely no benefit from it.

Jobst Brandt
[email hidden]

John Forrest Tomlinson said:

Quoted message said:

Some of the new high end racing products, like very light stems,
seem to cry out for very precise torque with very small bolts in
critical locations. I wouldn't dare use such a produce w/o a torque
wrench.

You don't need a torque wrench even for those. Stem's handlebar clamp
must be tightened sufficiently that the handlebars can't move in them no
matter how hard you yank on the brake lever hoods.

That is the test, not some arbitrary torque value on the wrench. If they
can't take that much tightening, they are not safe to ride.

The stem should be tightened onto or into the steerer enough to keep the
it from rotating around the steerer in normal use, but not so much that
the stem can't twist sideways if the bike falls over.

The proper test for this is to grip the front wheel betwixt your knees
and try to rotate the bars. It should be possible, but not too easy to
make the stem turn around the steerer. Trying to do this by some second
order process involving wrench torque is inherently less accurate.

Jobst took the words right out of my mouth:

Quoted message said:

I wouldn't use such equipment at all, given a choice. Why do
bicyclists like to drive themselves into an technical corner with
reliability and serviceability? This is masochism. What is the
motivation for all this pseudo aircraft lightness? 99.44% of people
buying this stuff gain absolutely no benefit from it.

I like to imagine two numbers, and the ratio between them. I don't know
what the numbers are, but I have a bit of a feel for the ratio.

One number is the number of races that have been won because one bike
was a little bit lighter than another bike.

The other number is the number of races lost due to something breaking.

Sheldon "Figure It Out" Brown
+------------------------------------------+
| Light, cheap, durable. Choose any two. |
| -- Keith Bontrager |
+------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

"Sheldon Brown" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

John Forrest Tomlinson said:

Quoted message said:

Some of the new high end racing products, like very light stems,
seem to cry out for very precise torque with very small bolts in
critical locations. I wouldn't dare use such a produce w/o a torque
wrench.

You don't need a torque wrench even for those. Stem's handlebar clamp
must be tightened sufficiently that the handlebars can't move in them no
matter how hard you yank on the brake lever hoods.

That is the test, not some arbitrary torque value on the wrench. If they
can't take that much tightening, they are not safe to ride.

The stem should be tightened onto or into the steerer enough to keep the
it from rotating around the steerer in normal use, but not so much that
the stem can't twist sideways if the bike falls over.

The proper test for this is to grip the front wheel betwixt your knees
and try to rotate the bars. It should be possible, but not too easy to
make the stem turn around the steerer. Trying to do this by some second
order process involving wrench torque is inherently less accurate.

Jobst took the words right out of my mouth:

Quoted message said:

I wouldn't use such equipment at all, given a choice. Why do
bicyclists like to drive themselves into an technical corner with
reliability and serviceability? This is masochism. What is the
motivation for all this pseudo aircraft lightness? 99.44% of people
buying this stuff gain absolutely no benefit from it.

I like to imagine two numbers, and the ratio between them. I don't know
what the numbers are, but I have a bit of a feel for the ratio.

One number is the number of races that have been won because one bike
was a little bit lighter than another bike.

The other number is the number of races lost due to something breaking.

Sheldon "Figure It Out" Brown
+------------------------------------------+
| Light, cheap, durable. Choose any two. |
| -- Keith Bontrager |
+------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Sheldon I've been using your Tork-Grip (
http://sheldonbrown.com/tork-grip.html ) for many years now and it has
served me well.
Surely you aren't suggesting I give up this precision tool and tighten
things according to "feel".

Marty

"Leo Lichtman" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

"John Everett" wrote: (clip)If the well-trained human body could reliably
repeat a mechanical function an NBA player would never miss a free-throw, a
major league pitcher would throw nothing but strikes, and Tiger Woods would
always hit the fairway. ;-)
^^^^^^^^^^^^^
Fortunately, the proper torque in most applications has a tolerance which
experienced mechanics can hit easily. If this were not true, then every
home shop would need a SET of torque wrenches. If I could torque bolts with
the accuracy that Tiger Woods achieves with his clubs, I think I would list
my only torque wrench on e-bay :-)

I assemble bikes all day long where I work. I use torque wrenches only
because I have a local place where get good deals on them. I collect
torque wrenches that interest me. My favorite ones are made by UTICA
and Snap-On. My favorite is the Snap-On QJR217C. I have a one inch
drive Snap-On dial type Torqueometer that goes up to 2000 foot pounds
in 50 foot pound increments. This is just in case anyone ever
complains that I do not torque anything tight enough. Some small
fasteners are usually overtightened by mechanics. I notice that some
bolts like 4mm allen seatpost clamp bolts and front derailleur anchor
bolts only require about 40 inch pounds according to manufacturers
specs. If there is a warranty problem on any bike part,I can always
claim that I used a torque wrench set to the specs. Torque wrenches
are best for crank arm bolts instead of the cheap knuckle busting
tools that most bike shops use. I have a boring job and fancy torque
wrenches make it more interesting. Torque wrenches guarantee more
consistent work. It is fun to see how many foot pounds it takes to
remove some stubborn freewheels. 300 foot pounds is my personal
record. _

Joseph Kochanowski said:

... I have a one inch
drive Snap-On dial type Torqueometer that goes up to 2000 foot pounds
in 50 foot pound increments. This is just in case anyone ever
complains that I do not torque anything tight enough....

This torque wrench would require a Chalo Colina equivalent weight at the
end of a 5-1/2 feet handle to achieve full capacity.

--
Tom Sherman

Sheldon Brown said:

You don't need a torque wrench even for those. Stem's handlebar clamp
must be tightened sufficiently that the handlebars can't move in them no
matter how hard you yank on the brake lever hoods.

That is the test, not some arbitrary torque value on the wrench. If they
can't take that much tightening, they are not safe to ride.

The stem should be tightened onto or into the steerer enough to keep the
it from rotating around the steerer in normal use, but not so much that
the stem can't twist sideways if the bike falls over.

The proper test for this is to grip the front wheel betwixt your knees
and try to rotate the bars. It should be possible, but not too easy to
make the stem turn around the steerer. Trying to do this by some second
order process involving wrench torque is inherently less accurate.

Quoted message said:

Sheldon "Figure It Out" Brown

Hi, yes I would think when you work on bikes regularly, you would
develope a feel for proper tightness. But for someone like me, who
only tightens things one in a while, a torque wrench is helpful. I
don't believe that they are necessary for every bolt. I use mine on
anything that relates to fastening carbon fiber components, like my
stem face plate, and seat clamp. I have a tendency to over tighten
things. I also used it on my crank bolts.

For me, better safe than sorry.

Life is Good!
Jeff

Joseph K. wrote:

<< I assemble bikes all day long where I work. I use torque wrenches only
because I have a local place where get good deals on them. I collect
torque wrenches that interest me. My favorite ones are made by UTICA
and Snap-On. My favorite is the Snap-On QJR217C. I have a one inch
drive Snap-On dial type Torqueometer that goes up to 2000 foot pounds
in 50 foot pound increments. This is just in case anyone ever
complains that I do not torque anything tight enough. Some small
fasteners are usually overtightened by mechanics. I notice that some
bolts like 4mm allen seatpost clamp bolts and front derailleur anchor
bolts only require about 40 inch pounds according to manufacturers
specs. If there is a warranty problem on any bike part,I can always
claim that I used a torque wrench set to the specs. Torque wrenches
are best for crank arm bolts instead of the cheap knuckle busting
tools that most bike shops use. I have a boring job and fancy torque
wrenches make it more interesting. Torque wrenches guarantee more
consistent work. It is fun to see how many foot pounds it takes to
remove some stubborn freewheels. 300 foot pounds is my personal
record. _ >>

So what's the best torque wrench for
installing cartridge BB?

Robert

I said:

Quoted message said:

You don't need a torque wrench even for [lightweight stems.]
Stem's handlebar clamp
must be tightened sufficiently that the handlebars can't move in them no
matter how hard you yank on the brake lever hoods.

That is the test, not some arbitrary torque value on the wrench. If they
can't take that much tightening, they are not safe to ride.

The stem should be tightened onto or into the steerer enough to keep the
it from rotating around the steerer in normal use, but not so much that
the stem can't twist sideways if the bike falls over.

The proper test for this is to grip the front wheel betwixt your knees
and try to rotate the bars. It should be possible, but not too easy to
make the stem turn around the steerer. Trying to do this by some second
order process involving wrench torque is inherently less accurate.

Jeff Starr said:

Hi, yes I would think when you work on bikes regularly, you would
develope a feel for proper tightness. But for someone like me, who
only tightens things one in a while, a torque wrench is helpful.

This could be so for some aspects. When I was starting working on
bikes, back in the '50s, I didn't know such a thing as a torque wrench
existed.

Quoted message said:

I don't believe that they are necessary for every bolt. I use mine on
anything that relates to fastening carbon fiber components, like my
stem face plate, and seat clamp. I have a tendency to over tighten
things.

The procedure outlined above is better than slavishly following some
arbitrary numbers.

I also used it on my crank bolts.

Quoted message said:

For me, better safe than sorry.

That platitude is certainly true as far as it goes, but the issue is
which approach is the safer one.

I believe in evaluating the actual individual parts, not using some
arbitrary number that was generated under unknown conditions, probably
rounded off, then translated in to different units and rounded off again.

Sheldon "Not A Robot" Brown
+-----------------------------------------------------+
| Life is the art of drawing sufficient conclusions |
| from insufficient premises. --Samuel Butler |
+-----------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

Marty Wallace said:

Sheldon I've been using your Tork-Grip

http://sheldonbrown.com/tork-grip.html

Quoted message said:

for many years now and it has served me well. Surely you aren't
suggesting I give up this precision tool and tighten things
according to "feel".

Some people have less of a mechanical touch or engineering feel for
materials than others, but should not be denied the maintenance of
their equipment for that. Such tools are needed in some marginal
applications where tight enough is close to too tight. Torque
wrenches are not an idle invention but are unnecessary for most people
familiar with conventional machinery.

Having assembled bicycles, motorcycles, and cars since early youth,
rebuilding engines and installing components successfully without a
torque wrench, I plan on continuing to do so. That isn't saying that
everyone will have success that way. I disagree with the naysayers
who use the term "experienced mechanic" disparagingly to prove that
even they cannot work correctly without a torque wrench. I think
these people are not good judges of who is a GOOD experienced mechanic
and when such a wrench is needed.

A good indication that a torque wrench is needed is that screws strip
or parts break on assembly, or that parts come loose and fail.

Jobst Brandt
[email hidden]

jobst brandt said:

Marty Wallace said:

Sheldon I've been using your Tork-Grip

http://sheldonbrown.com/tork-grip.html

Quoted message said:

for many years now and it has served me well. Surely you aren't
suggesting I give up this precision tool and tighten things
according to "feel".

Some people have less of a mechanical touch or engineering feel for
materials than others, but should not be denied the maintenance of
their equipment for that. Such tools are needed in some marginal
applications where tight enough is close to too tight. Torque
wrenches are not an idle invention but are unnecessary for most people
familiar with conventional machinery.

I recommend a perusal of the posted link.

--
Benjamin Lewis

millihelen, n.:
The amount of beauty required to launch one ship.

Jobst Brandt wrote:

<< Some people have less of a mechanical touch or engineering feel for
materials than others, but should not be denied the maintenance of
their equipment for that. Such tools are needed in some marginal
applications where tight enough is close to too tight. Torque
wrenches are not an idle invention but are unnecessary for most people
familiar with conventional machinery.

Having assembled bicycles, motorcycles, and cars since early youth,
rebuilding engines and installing components successfully without a
torque wrench, I plan on continuing to do so. That isn't saying that
everyone will have success that way. I disagree with the naysayers
who use the term "experienced mechanic" disparagingly to prove that
even they cannot work correctly without a torque wrench. I think
these people are not good judges of who is a GOOD experienced mechanic
and when such a wrench is needed.

A good indication that a torque wrench is needed is that screws strip
or parts break on assembly, or that parts come loose and fail. >>

The OQ was about cartridge BBs. What's the verdict?

Robert

Benjamin Lewis said:

Quoted message said:

Quoted message said:

Sheldon I've been using your Tork-Grip

http://sheldonbrown.com/tork-grip.html

Quoted message said:

Quoted message said:

Quoted message said:

for many years now and it has served me well. Surely you aren't
suggesting I give up this precision tool and tighten things
according to "feel".

Quoted message said:

Quoted message said:

Some people have less of a mechanical touch or engineering feel for
materials than others, but should not be denied the maintenance of
their equipment for that. Such tools are needed in some marginal
applications where tight enough is close to too tight. Torque
wrenches are not an idle invention but are unnecessary for most
people familiar with conventional machinery.

Quoted message said:

I recommend a perusal of the posted link.

Thanks, I hadn't done that in awhile but now that you mention it, I am
reminded that one picture is worth 10,000 inch ponds.

Jobst Brandt
[email hidden]