4mm screws that take 5mm Allen key? (thinly-disguised rant...)



RE/
>Having stripped out a few 5mm stem clamp bolts, I welcome a
>manufacturer who specifies torque for their fasteners.

Reading Thompson's instructions, I came away with the
notion that the whole friggin' thing will fail if over *or*
under torqued.

OTOH, maybe it's the lawyer's talking...but it doesn't
exactly give me a warm and fuzzy feeling...In someething
like a stem, if bulletproof and sophisticated collide, I
want bulletproof.
--
PeteCresswell
 
I keep both mm and American Allen wrenches handy and you
can't go wrong.

I MTB 2004
 
"(Pete Cresswell)" <[email protected]> wrote in message
news:[email protected]...
> RE/
> >Having stripped out a few 5mm stem clamp bolts, I welcome
> >a manufacturer
who
> >specifies torque for their fasteners.
>
> Reading Thompson's instructions, I came away with the
> notion that the
whole
> friggin' thing will fail if over *or* under torqued.
>
> OTOH, maybe it's the lawyer's talking...but it doesn't
> exactly give me a
warm
> and fuzzy feeling...In someething like a stem, if
> bulletproof and
sophisticated
> collide, I want bulletproof.

Thomson stems and seatposts are both bulletproof and
sophisticated. They're one of those things you can bolt on
your bike and simply forget about. I run their seatposts on
all my bikes, three are DH bikes. I've seen DH seats ripped
off their rails and the Thomson dutifully holding on the
bent and twisted rails. Pete F. has a pic of one with a bad
dent in it from a rock but from what I could tell from the
pic it was still working for the ride home.

Mike
 
> The only explanation I can come up with is that since
> there are 4 bolts holding the face plate to that stem,
> they decided to go with a smaller
bolt
> to save weight. You see the 2-bolt stems all have big
> thick bolts because they have to bear twice the load.
>
> I have Thomson stems on two of my bikes, and I have to
> say... I'm not that impressed. They aren't that light and
> they aren't that easy to adjust (4 bolt face plates are a
> pain to torque properly without binding!). I don't like
> the eccentric steerer clamp, as it, too, is more difficult
> to adjust. They *do* say "Thomson" on them, but I see
> myself going back to a lighter weight 2-bolt stem on my
> next bike.

Ugh... 2-bolts are incredibly flexy (the bolts do virtually
nothing in response to torque around an axis through the
center of the bike and handlebar)... on the magnitude of an
inch of deflection at the ends of the handlebars!!!

Stem in question: Salsa Moto-Ace. Replaced with a Ritchey
Pro 4-bolt (even lighter) and no such flex. I'll NEVER go
back to 2-bolts...

--
Phil, Squid-in-Training
 
"John Morgan" <[email protected]> wrote in message
news:pBDDc.11835$6r1.9354@fed1read06...
> KLydesdale wrote:
>
> > You should just grind slots in all the fasteners on your
> > bike. That way you only have to carry a flat-bladed screw-
> > driver.
>
> Why? I'd rather just carry a multi-tool with the common
> size hex wrenches in it.

He forgot the smiley.

--
Phil, Squid-in-Training
 
(Pete Cresswell) wrote:

> Reading Thompson's instructions, I came away with the
> notion that the whole friggin' thing will fail if over
> *or* under torqued.

Is this the first instruction manual you've read? I think
most cover their asses in much the same way...
 
"(Pete Cresswell)" <[email protected]> wrote in message
news:[email protected]...
> I'm setting up my new semi-custom FS. LBS said that
> Thompson's
super-duper
> stem was the only one that fit the size/angle spec, so I
> said "OK".
>
> I'm putting this thing together and grab my trusty 5mm
> allen key that fits
all
> the brake screws, the saddle adjustment screws, the
> seatpost clamp screws....even the cap screw on the
> steering tube.... and probably a few
more
> things that don't come to mind right now...
>
> Oops...some genius has used 4mm screws on the Thompson
> stem's clamp.
>
<Snip rant>

I understand your frustration but I think there are valid
reasons Thomson chose 4mm bolts. As someone else mentioned
this allows more material to be used in the actual stem, but
also I suspect it lessens the chance of an over-zealous
mechanic applying too much torque.

And if you think 4 bolt face-plates are too much hassle,
have a look at this little beauty:

http://www.alansbmx.com/product_info.php?cPath=32_47&produc-
ts_id=1024

Steve.
 
ZeeExSixAre wrote:

> Ugh... 2-bolts are incredibly flexy (the bolts do
> virtually nothing in response to torque around an axis
> through the center of the bike and handlebar)... on the
> magnitude of an inch of deflection at the ends of the
> handlebars!!!

Agreed. 4 bolt clamps are the way forward.
 
S o r n i wrote:
> KLydesdale wrote:
>> "(Pete Cresswell)" <[email protected]> wrote in message
>> news:[email protected]...
>>> RE/
>>>> "WARNING:
>>>
>>> It gets even better: "WARNING: Torque Wrench Required
>>> For Assembly....".... well, I guess my comments about
>>> ease of adjustment in the field were kind of off-base...
>>> --
>>> PeteCresswell
>>
>> Having stripped out a few 5mm stem clamp bolts, I welcome
>> a manufacturer who specifies torque for their fasteners.
>
> You mean you're actually supposed to /adhere/ to specs?!?
>
> Bill "fascinating concept" S.

Only if you make the mistake of reading the
instructions first.

Parbs
 
"(Pete Cresswell)" <[email protected]> wrote in message news:<[email protected]>...
> I'm setting up my new semi-custom FS. LBS said that
> Thompson's super-duper stem was the only one that fit the
> size/angle spec, so I said "OK".

[snip]

I might have missed it, but here's something that might be
a benefit:

Since manny of the other fasteners on a bike are 5mm, that's
all a thief needs to really take a good load of gear. Like a
really nice Marzocchi fork - undo the QR, use your trusty
5mm to undo the stem, walk off with a $500 fork.

I REALLY like the way the Thomson clamps the steerer. My
knees are very thankful. That feature alone is worth it to
me. And weight? If you wanted featherweight, get a Moots Ti
stem. Sure, it's over $200, but it's way cool. :)

I have a set of hex head sockets. After it's all hand-tight,
I go back and torque it down using a torque wrench. No
different than any other bike fastener. And with a glob of
grease on the threads and the back of the bolt head, I have
never had a single binding problem. I dunno, it's just not
much more complicated than a 2-bolt stem, nor are the
instructions any more lawyerese than any other product. Read
a Marzocchi owner's manual. Sheesh.

The reason I went to Thomson for seatposts was the high
degree of adjustability of the seat angle, but more than
that, *no setback*. But I chose the stem specifically for it
being a four-bolt face.
--
Jonesy
 
> Is this the first instruction manual you've read? I think
> most cover their asses in much the same way...

Most of the stuff I buy is below the level at which mfrs
provide instructions.
 
RE/
>Ugh... 2-bolts are incredibly flexy (the bolts do virtually
>nothing in response to torque around an axis through the
>center of the bike and handlebar)... on the magnitude of an
>inch of deflection at the ends of the handlebars!!!

Although I can distinguish between the flex inherant in the
5" risers I was using and that from the 2-bolt stem what was
on there with it; it's obvious even to me that the new setup
with 2.5" risers and the Thompson stem is a *lot* stiffer....rock-
solid, even.....and that's the main reason I went over to a
semi-custom bike - to get the extra steering tube so I could
mount a normal bar/stem setup.
--
PeteCresswell
 
"ZeeExSixAre" <[email protected]> wrote in message
news:[email protected]...
>
> "John Morgan" <[email protected]> wrote in message
> news:pBDDc.11835$6r1.9354@fed1read06...
> > KLydesdale wrote:
> >
> > > You should just grind slots in all the fasteners on
> > > your bike. That
way
> > > you only have to carry a flat-bladed screw-driver.
> >
> > Why? I'd rather just carry a multi-tool with the common
> > size hex
wrenches
> > in it.
>
> He forgot the smiley.
>
> --

I forgot how to do the one showing tongue firmly
implanted in cheek.
 
"PeteCresswell" <[email protected]> wrote in message
news:[email protected]...
> > Is this the first instruction manual you've read? I
> > think most cover
their
> > asses in much the same way...
>
> Most of the stuff I buy is below the level at which
> mfrs provide
instructions.

No need to consult the instruction manual for those specs on
some stems. Check out the fine print on the faceplate of
this Specialized one.

http://www.specialized.com/SBCEqProduct.jsp?spid=5062&JServ-
SessionIdroot=f0r ostvr16.j27010

Now somebody's thinking!
 
KLydesdale wrote:
> "PeteCresswell" <[email protected]> wrote in
> message
> news:[email protected]...
>>> Is this the first instruction manual you've read? I
>>> think most cover their asses in much the same way...
>>
>> Most of the stuff I buy is below the level at which mfrs
>> provide instructions.
>
> No need to consult the instruction manual for those specs
> on some stems. Check out the fine print on the faceplate
> of this Specialized one.
>
>
http://www.specialized.com/SBCEqProduct.jsp?spid=5062&JServ-
SessionIdroot=f0r
> ostvr16.j27010
>
> Now somebody's thinking!

Have you seen some of Specialized's short road stems? Check
out an Allez or Roubaix and look closely at the body of the
stem... the tribal-looking lines on the stem are actually
tiny tiny words... the standard fare of course (alloy, heat
treated, torques, etc.)

--
Phil, Squid-in-Training
 
(Pete Cresswell) <[email protected]> wrote:
> RE/
> >news:[email protected]...

> Ahhh! the coup de Grace: "WARNING: Use only specially-
> designed Thomson shims with the Thompson Stem. Standard
> shims will not work."

> I'm guessing that "shims" are what I call "spacers".

> What, are these guys on drugs?

http://www.lhthomson.com/stemfaq.asp

You're overthinking.

"Shims" are what adapt a 1-1/8" stem to a 1" steer tube.

BTW, I have never touched a Thomson stem, but I bet the
screws that take a 4mm hex wrench are 5mm diameter, not 4mm.
 
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