"TomYoung" <
[email protected]> wrote in message
news:
[email protected]...
> On Jun 16, 6:04 pm, Mark <[email protected]>
> wrote:
> > TomYoung wrote:
> > > Hi all:
> >
> > > For several months now I've been fighting a creaking noise coming
from
> > > the handlebar/stem/steerer tube area. Anytime I stand to climb it's
> > > creak, creak, creak. Even straddling the bike flat-footed and
> > > alternately pushing down on opposite ends of the handlebar will
> > > produce the noise. I've taken things apart maybe 3-4 times now,
> > > cleaning, inspecting, greasing, etc. (I've tried both grease and no
> > > grease where the stem clamps the handlebar) and even if I get the
> > > creaking noise to go away it soon returns.
> >
> > > It dawned on me today that the one thing I haven't done is remove
the
> > > headset cups from the headtube. The bike has about 25,000 - 30,000
> > > miles on it with the same headset cups. The headset is Ultegra so
> > > when the sealed bearings started to grind sometime back I just
> > > replaced the sealed bearing since there's no real bearing-cup
> > > contact. Is there some sort of wear here that could be causing the
> > > noise? The cups are mounted on a Merlin Road bike, if that's at all
> > > relevant.
> >
> > Is it a quill stem or a threadless?
> >
> > If it's a quill, examine the front of the quill where it contacts the
> > headset locknut. There's a "lot" of flex in a quill stem design (by
"a
> > lot" I mean that the stem is free to rock some fraction of a
millimeter
> > inside the locknut.) It may be scraping there causing the creak.
> >
> > I de-creaked the infamous Cinelli quill by sliding a tiny bit of thick
> > plastic bag between the front of the quill and the locknut, after
> > observing tiny scrape marks on the front of the stem. Since the
binding
> > of the stem is at the bottom, not near the lockring, this poses no
hazard.
> >
> > If it's a threadless, sorry, I don't have any ideas for you, but my
wild
> > guess is that it isn't the cups.
> >
> > Mark J.
>
> Hmm.... Posted a reply earlier via Google Groups and GG said the post
> was successful but I'm not seeing my reply.
>
> Anyway, the setup's a quill stem adapter (ITM) to which I've attached
> a Deda Zero stem which is clamped to a Deda Elimenti handlebar. The
> ITM adapter claims one of the lowest weights I've seen for these sort
> of adapters and I'm guessing this low weight is obtained by the
> adapter's quill portion (the section buried inside the steerer tube)
> being shorter than that of other adapters. I also have the adapter
> raised to its minimum insertion point and the combination of short
> quill minimally inserted might be the source of the problem. I'll try
> your solution and see if that helps things.
>
> Thanks!
>
> Tom Young
>
The problem could likely be the ITM quill stem adapter.
My guess is that you have a light weigh, thin wall quill adapter and a
bellmouth steering tube. The adapter is minimally inserted and is able to
move around freely at the top when under pressure.
Both Nitto and Cinelli make what I consider safe quill stem adapters that
come in several lengths. If you ever ride out of the saddle or in a
straight away sprint you will usually be putting a lot of side to side
loading on the bars. Saving a few ounces in a critical area like the stem
is plain assed foolish!
Let me say that after having 3 quill stems break off while riding I have a
healthy regard for using strong stems. Two of the breaks occurred while
road testing customer's bikes - they were both cheap Bike Boom bikes with
cast aluminum stems. The third was my own bike, I used a supposedly high
quality French stem but it was made of cast aluminum too. I was lucky to
be able to stop the bikes without any injury.
With a quill style stem you should keep the quill inserted to the maximum
or minimum line on the stem. Also, some bikes with threaded headsets have
a long threaded area on the steering tube. Expanding the stem wedge inside
this threaded area can cause the steering tube to crack in the threads and
eventually break off leaving you holding the bars.
Steering tubes and stem diameters are not all that accurate. I have a
bunch of Cinelli 1/A stems which were considered the best available. The
quills are supposed to be 22.2mm (.874) diameter. Mine range from 22.05mm
to 22.25mm measured with a digital micrometer. I also have several French
Cinelli stems that measure 21.9mm - correct stem size and 22.0mm.
I put a brand new 22.2mm Cinelli 1/A stem into a late 80s steel Colnago.
It creaked every time I started or stopped. The steering tube was
bellmouthed at the top. I had to put a thin shim in one spot between the
stem and the tube to stop the creaking.
Chas.
