whats up with greasing or not greasing threadless steerers?

Nate Knutson said:

Many sources say different things about whether to grease stem/steer
contact areas where both parts are either steel or aluminum. All the
manufacturers instructions I've looked at (Salsa, ITM, Thomson,
probably some others) say not to, some specifically saying it's a
safety risk. Many/most technical sources seem to be in agreement. Yet
many, many people always grease it, including many who usually seem to
know what they're doing. I grease it on my own bikes regardless of
instructions and haven't had any problems, always doing the "try
twisting it sideways really hard" test first, but yet I'm still too
skeptical to second guess instructions in this regard on other people's
bikes I'm working on. I'm slowly trying to eliminate the number of
things I'm compelled to be schizo about like this.

What's the deal? Can greasing it ever actually cause spontaneous
movement or other problems? In this kind of mechanical application,
does greasing the interface even make a difference of much more than
zero in terms of how easily it can slip, given there's enough force
holding the parts together to keep slippage from occuring when
installed without lubrication?

How do stems that have much less stem/steerer contact area than normal
enter into this? What about ti stems? Anodized steerers?

If there are some cases where you shouldn't grease it, does that mean
you need to be super cautious about degreasing it in a way that leaves
zero residue?

The same discussion can be had for the bar/stem interface. I greased
this too on my own bikes until I had some slippage on a bike with a
pretty janky stem. Haven't really wanted to mess with it since then,
even though there could have been other factors at work then.

I don't want to start a long pointless thread but this seems important
given that one camp feels it's so important for safety not to use
grease. The other thing is that not much is really gained by greasing
these interfaces in most cases, but it does help prevent corrosion of
the steerer, probably has some effect on water intruding into the
headset, and with the handlebar/stem interface can eliminate noises
(not sure if this ever applies to stem/steerer).

do NOT grease carbon. the rest is optional imo. if you ride in the
wet, grease is pretty much essential if you ever care to disassemble the
bike a couple of years down the road. if you only ever ride on warm
sunny days and don't sweat, you'll be fine dry. again, do NOT grease
carbon.

On 19 Mar 2006 05:48:12 -0800, "Nate Knutson" <[email hidden]>

Quoted message said:

What's the deal? Can greasing it ever actually cause spontaneous
movement or other problems? In this kind of mechanical application,
does greasing the interface even make a difference of much more than
zero in terms of how easily it can slip, given there's enough force
holding the parts together to keep slippage from occuring when
installed without lubrication?

Two issues:

First, the clamp is designed to grip dry; lube the interface and you
increase the amount of squeeze produced by a given clamp bolt tension.
For a common steel steerer, this is extermely unlikely to overstress
the tube and crush it. Ditto most aluminum steerers with their thick
walls, but beware if the aluminum tube is of the same wall thickness
as a common steel steerer of the same OD. I would *never* grease a
carbon steerer; that's just asking for a crushed tube.

Second, if the clamp bolts work loose (uncommon) or the threads strip
(it can happen), the stem will be able to slip while there's still
some tension on the clamp. Of course, it can be argued that this
merely accelerates the time at which the failure is perceived, and
does not change the fact that there *is* a failure.

Quoted message said:

How do stems that have much less stem/steerer contact area than normal
enter into this? What about ti stems? Anodized steerers?

The only purpose the grease could serve would be to prevent interface
corrosion. Given that such corrosion is unlikely to cause any
in-service issues, and in my experience isn't particularly common
anyway[1], trying to prevent it in this manner seems to me like a
solution in search of a problem that may not exist.

Quoted message said:

If there are some cases where you shouldn't grease it, does that mean
you need to be super cautious about degreasing it in a way that leaves
zero residue?

Use your own judgement; I won't be there to render mine, and I can't
say from here.

Quoted message said:

The same discussion can be had for the bar/stem interface. I greased
this too on my own bikes until I had some slippage on a bike with a
pretty janky stem. Haven't really wanted to mess with it since then,
even though there could have been other factors at work then.

The rotational stresses on the bars are much greater. Grease there
can, in my experience, cause problems. It's hard enough to keep the
bars from rotating sometimes even without grease making it worse. (In
one memorable instance, I ended up antigreasing the clamp; I put some
water-based Clover compound in there. Others have resorted to cola
can shims with excellent results. On the whole, I think the shim is
probably the better choice.)

Quoted message said:

I don't want to start a long pointless thread but this seems important
given that one camp feels it's so important for safety not to use
grease. The other thing is that not much is really gained by greasing
these interfaces in most cases, but it does help prevent corrosion of
the steerer,

Which I feel is a non-problem in most cases. YMMV. Grease is not the
only way to address this.

Quoted message said:

...probably has some effect on water intruding into the
headset,

How? Water coming down the outside of the stem, or down the clamp
opening, is much more likely to be able to get into the bearing than
water that may capillary-creep through the clamped area.

Quoted message said:

and with the handlebar/stem interface can eliminate noises
(not sure if this ever applies to stem/steerer).

If you hear a creak in that area, IMO either the clamp isn't tight
enough, the headset preload is too low, the steerer tube has too much
flexure, the creak is really somewhere else, or there's a much more
serious issue than lack of grease in the stem clamp. I'd expect
grease in the clamp to mask an actual problem more often than to
address one.

[1] I have heard two reports of significant stem/steerer corrosion.
Both were attributed to sweat buildup; both were on bikes that were
ridden hard all winter on a trainer. Sweat damage to things on bikes
used on trainers is nothing new. A pedestal fan in front of the bike
may help, but so will a towel over the bars.
--
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Per Werehatrack:

Quoted message said:

If you hear a creak in that area, IMO either the clamp isn't tight
enough, the headset preload is too low, the steerer tube has too much
flexure, the creak is really somewhere else, or there's a much more
serious issue than lack of grease in the stem clamp. I'd expect
grease in the clamp to mask an actual problem more often than to
address one.

I'm using a Thompson MTB stem and somewhere along the line I got the message
that greasing it was a bad idea. In fact, I wound up with a major creak in it
once and was told that maybe it was "contaminated" with grease. Whatever the
cause, I disassembled it, wiped everything down with alcohol, reassembled - and
the creak was gone.
--
PeteCresswell

(PeteCresswell) said:

Per Werehatrack:

Quoted message said:

If you hear a creak in that area, IMO either the clamp isn't tight
enough, the headset preload is too low, the steerer tube has too much
flexure, the creak is really somewhere else, or there's a much more
serious issue than lack of grease in the stem clamp. I'd expect
grease in the clamp to mask an actual problem more often than to
address one.

I'm using a Thompson MTB stem and somewhere along the line I got the
message that greasing it was a bad idea. In fact, I wound up with a
major creak in it once and was told that maybe it was "contaminated"
with grease. Whatever the cause, I disassembled it, wiped
everything down with alcohol, reassembled - and the creak was gone.

As mentioned before, Thomson stems are adjusted in a different manner than
most other traditional threadless stems. If the clamp was tightened in a
skewed fashion such that one bolt was tightened more than the other,
relative movement and thus creaking can occur. I don't buy the
"contaminated" argument.
--
Phil, Squid-in-Training

Per Phil, Squid-in-Training:

Quoted message said:

If the clamp was tightened in a
skewed fashion such that one bolt was tightened more than the other,
relative movement and thus creaking can occur. I don't buy the
"contaminated" argument.

Sounded a little goofy to me too, but that's what they said.

I like the "skew" rationale - and re-torquing the bolts would have balanced out
the skew.
--
PeteCresswell