Square taper, grease or not!!!!
- Thread starter dicoverybmw
- Start date
Ding, Ding, Ding, Ding - Round 10. Dedicated to Woz, Wookie, LGF, FC and the rest...
Yet the No minions sought release
for their right to be sans grease
and fought to have fair say,
so the RB bastions they did storm, until their views became the norm
and the thread still runs to this day.
:mrgreen:
Yet the No minions sought release
for their right to be sans grease
and fought to have fair say,
so the RB bastions they did storm, until their views became the norm
and the thread still runs to this day.
:mrgreen:
The Ballad of the Ungreased Taper (in 3 part harmony)
In the year 2013
Assembled here the uninformed,
In the day when their cranks were dry...
and a 'dollop" (or was it wallop?) was applied
to the drive and non-drive side,
so in RB hell they shall not fry.
Yet the No minions sought release
for their right to be sans grease
and fought to have fair say,
so the RB bastions they did storm, until their views became the norm
and the thread still runs to this day.
In the year 2013
Assembled here the uninformed,
In the day when their cranks were dry...
and a 'dollop" (or was it wallop?) was applied
to the drive and non-drive side,
so in RB hell they shall not fry.
Yet the No minions sought release
for their right to be sans grease
and fought to have fair say,
so the RB bastions they did storm, until their views became the norm
and the thread still runs to this day.
- Feedback
- View
OH DEAR, i have just converted from no grease to grease
now i was always an impressionable fence jumper
but having read this
http://206.75.155.18/kmr/crankbb.html
and this
http://206.75.155.18/kmr/bbcreak.html
i fear he is right
in particular this
The reason to lube the tapers is to prevent galling and fretting from occurring
during installation. Basically, what this IS is that while the machined tapers
of the Ti (or CrMo) spindle appear smooth to the naked eye or to the touch of your
fingers, when viewed under high magnifaction (like 1000x), they are actually
quite rough with peaks and valleys and sharp edges. When you're pressing the cranks on,
which are almost always aluminium and softer than the Titanium spindle,
the BB tapers are acting like minature files and removing small flakes
of aluminium from the crank tapers. These flakes then become trapped between
the crank & BB tapers, leading to an imperfect press-fit and are the MAIN source
of creaking noises.
For many decades, there has been an old wives tale unique to the bicycle
industry about greasing the spindle tapers being a major no-no and sure fire way
to over-install the cranks. This is a myth, pure and simple. Its only now that
crank & BB makers are doing their own R&D and correcting their manuals and
informing consumers and bike mechanics to lubricate the tapers. RaceFace manuals
state to do this now when originally they said not to do it, Shimano's master
bible for installing their parts say to do it (and they even ship the BB spindles now with
grease on the tapers already, ready to install), and the latest edition of the
Sutherlands manual says to lube the tapers.
You clean the tapers before applying the grease to remove any aluminum particles
that were removed from the crank tapers and have become trapped in place as the
cranks are installed. You use the grease (or anti-seize, either works, I use
a waterproof marine grease myself) to prevent galling and fretting when the
crankarms are installed (this is what causes the aluminum flakes to break off).
Contrary to popular belief, the crank/bb assembly of a bike is NOT a
friction-fit, nor is it really a press-fit... it is an INTERFERENCE-fit. What's
holding the cranks on is the plastic deformation of the metals involved. The
softer metal will deform around the harder metal (ever so slightly), and in
concert with the crank bolts, this holds the crankarm in place (once sufficient
deformation has taken place). It is NOT dependant on friction, nor will the
presence of grease prevent this deformation from taking place. The presence of
small particles of aluminum that were ground off the tapers by the galling and
fretting which occured from excessive friction during the installation process
(say, from a dry-fit assembly) however, can lead to an improper interference-fit
and the symptom of this, is the dreaded creaking whenever torque is applied to
the cranks.
This is galling & fretting is MORE likely to occur with BB spindles (Ti or CrMo)
which are machined rather than forged. MOST CrMo spindles are forged, because
its cheaper for the big companies (like shimano) to make MANY identical parts
this way. In the case of Ti BBs (and some aftermarket CrMo BBs), the spindles
are machined, which leaves a rougher surface on the tapers than forging. This
rough surface, which may appear smooth to your fingertips, is actually quite
abrasive to the aluminum tapers of your typical crankarm. If there's too much
friction when you install the aluminum cranks, galling & fretting occurs and
tiny pieces (usually too small to see with the naked eye) break off and become
trapped in places where you don't want them...
Any other questions?!?
So TKO or RSC i think
now i was always an impressionable fence jumper
but having read this
http://206.75.155.18/kmr/crankbb.html
and this
http://206.75.155.18/kmr/bbcreak.html
i fear he is right
in particular this
The reason to lube the tapers is to prevent galling and fretting from occurring
during installation. Basically, what this IS is that while the machined tapers
of the Ti (or CrMo) spindle appear smooth to the naked eye or to the touch of your
fingers, when viewed under high magnifaction (like 1000x), they are actually
quite rough with peaks and valleys and sharp edges. When you're pressing the cranks on,
which are almost always aluminium and softer than the Titanium spindle,
the BB tapers are acting like minature files and removing small flakes
of aluminium from the crank tapers. These flakes then become trapped between
the crank & BB tapers, leading to an imperfect press-fit and are the MAIN source
of creaking noises.
For many decades, there has been an old wives tale unique to the bicycle
industry about greasing the spindle tapers being a major no-no and sure fire way
to over-install the cranks. This is a myth, pure and simple. Its only now that
crank & BB makers are doing their own R&D and correcting their manuals and
informing consumers and bike mechanics to lubricate the tapers. RaceFace manuals
state to do this now when originally they said not to do it, Shimano's master
bible for installing their parts say to do it (and they even ship the BB spindles now with
grease on the tapers already, ready to install), and the latest edition of the
Sutherlands manual says to lube the tapers.
You clean the tapers before applying the grease to remove any aluminum particles
that were removed from the crank tapers and have become trapped in place as the
cranks are installed. You use the grease (or anti-seize, either works, I use
a waterproof marine grease myself) to prevent galling and fretting when the
crankarms are installed (this is what causes the aluminum flakes to break off).
Contrary to popular belief, the crank/bb assembly of a bike is NOT a
friction-fit, nor is it really a press-fit... it is an INTERFERENCE-fit. What's
holding the cranks on is the plastic deformation of the metals involved. The
softer metal will deform around the harder metal (ever so slightly), and in
concert with the crank bolts, this holds the crankarm in place (once sufficient
deformation has taken place). It is NOT dependant on friction, nor will the
presence of grease prevent this deformation from taking place. The presence of
small particles of aluminum that were ground off the tapers by the galling and
fretting which occured from excessive friction during the installation process
(say, from a dry-fit assembly) however, can lead to an improper interference-fit
and the symptom of this, is the dreaded creaking whenever torque is applied to
the cranks.
This is galling & fretting is MORE likely to occur with BB spindles (Ti or CrMo)
which are machined rather than forged. MOST CrMo spindles are forged, because
its cheaper for the big companies (like shimano) to make MANY identical parts
this way. In the case of Ti BBs (and some aftermarket CrMo BBs), the spindles
are machined, which leaves a rougher surface on the tapers than forging. This
rough surface, which may appear smooth to your fingertips, is actually quite
abrasive to the aluminum tapers of your typical crankarm. If there's too much
friction when you install the aluminum cranks, galling & fretting occurs and
tiny pieces (usually too small to see with the naked eye) break off and become
trapped in places where you don't want them...
Any other questions?!?
So TKO or RSC i think
- Feedback
- View
I still had an unopened UN-55 box, so I opened it, took out the instructions and scanned the complete English page. Here it is :
As you may notice, it doesn't mention grease on the tapers. The BB comes whith grease inside the axle bolt treads and the manual only mentions greasing the threads that connect it to the frame. but NOT on the tapers.
And sorry, but I can't let this one slide :
I'll take the word from someone who has done plenty of miles on bikes he maintains himself over that of any engineer who doesn't work for a bicycle component manufacturer.
My own experience (20 years of maintaining my own bikes, around 120K miles total) indicates that it doesn't matter one iota whether you grease them or not. Creaking is usually the result of sand/dirt on the tapers, not from lack of grease.
As for Sheldon Brown mentioning using grease, does he by any chance tell you to use a specific grease that you can coincidentally buy via his website?
After reading the chain cleaning article/commercial, I've learned to take his words with a grain of salt ... or rather a mountain of it. IMO he doesn't mind telling absolute nonsense if that enables him to sell a few more things.
As you may notice, it doesn't mention grease on the tapers. The BB comes whith grease inside the axle bolt treads and the manual only mentions greasing the threads that connect it to the frame. but NOT on the tapers.
And sorry, but I can't let this one slide :
BMW and the RAF have their field of expertise. However it doesn't include BBs.dyna-ti":1gc1twe6 said:
I'll take the word from someone who has done plenty of miles on bikes he maintains himself over that of any engineer who doesn't work for a bicycle component manufacturer.
My own experience (20 years of maintaining my own bikes, around 120K miles total) indicates that it doesn't matter one iota whether you grease them or not. Creaking is usually the result of sand/dirt on the tapers, not from lack of grease.
As for Sheldon Brown mentioning using grease, does he by any chance tell you to use a specific grease that you can coincidentally buy via his website?
After reading the chain cleaning article/commercial, I've learned to take his words with a grain of salt ... or rather a mountain of it. IMO he doesn't mind telling absolute nonsense if that enables him to sell a few more things.
"As you may notice, it doesn't mention grease on the tapers. The BB comes whith grease inside the axle bolt treads and the manual only mentions greasing the threads that connect it to the frame. but NOT on the tapers."
That's because it's a BB Installation Instruction and not a Crank Installation Instruction. It doesn't say "Don't grease the tapers" either
Check the link I posted earlier; it's from one of the very last reasonably decent square taper cranks Shimano made. Interesting that Shimano even launched the UN55 (LX or 105 level) but no square taper crank to match .
That's because it's a BB Installation Instruction and not a Crank Installation Instruction. It doesn't say "Don't grease the tapers" either
Check the link I posted earlier; it's from one of the very last reasonably decent square taper cranks Shimano made. Interesting that Shimano even launched the UN55 (LX or 105 level) but no square taper crank to match .
