Machined from a solid extruded block vs. Forging

[Llatikcuf]

Talked to the people at Thomson today about their stems, he said they
were machined from a solid extruded block and related the idea of clay
being pushed through a small opening. How does extruding a solid block
of aluminum compare in strength and fatigue resistance to the item
being forged?

-Nate

 

[Werehatrack]

On 25 Jan 2006 15:31:37 -0800, "Llatikcuf" <[email protected]>
wrote:

>Talked to the people at Thomson today about their stems, he said they
>were machined from a solid extruded block and related the idea of clay
>being pushed through a small opening. How does extruding a solid block
>of aluminum compare in strength and fatigue resistance to the item
>being forged?

Forging shapes the grain of the material to better align it with the
surface of, and presumably the stresses applied to, the item.
Machining the item from an extrusion puts all the grain in one
direction, some of it perpendicular to the machined surface.
Thomson's choice of method is still superior to making the part from a
casting, however, and their reputation is pretty good. Since you don't
have the option of getting a Thomson stem that's forged, the important
question is not whether their choice of method is the best possible,
but rather if it's adequate for the task.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Llatikcuf]

Werehatrack wrote:
> Thomson's choice of method is still superior to making the part from a
> casting, however, and their reputation is pretty good. Since you don't
> have the option of getting a Thomson stem that's forged, the important
> question is not whether their choice of method is the best possible,
> but rather if it's adequate for the task.

Indeed, yet one is left to wonder why Thomson decided to do it this
way. Do they believe it's stronger than it's forged competitor?

-Nate

 

[philcycles]

Llatikcuf wrote:
> Werehatrack wrote:
> > Thomson's choice of method is still superior to making the part from a
> > casting, however, and their reputation is pretty good. Since you don't
> > have the option of getting a Thomson stem that's forged, the important
> > question is not whether their choice of method is the best possible,
> > but rather if it's adequate for the task.
>
> Indeed, yet one is left to wonder why Thomson decided to do it this
> way. Do they believe it's stronger than it's forged competitor?
>
> -Nate

Cost. It's cheaper than making forgiing dies.
Phil brown

 

[Werehatrack]

On 25 Jan 2006 17:44:39 -0800, "philcycles" <[email protected]>
wrote:

>
>Llatikcuf wrote:
>> Werehatrack wrote:
>> > Thomson's choice of method is still superior to making the part from a
>> > casting, however, and their reputation is pretty good. Since you don't
>> > have the option of getting a Thomson stem that's forged, the important
>> > question is not whether their choice of method is the best possible,
>> > but rather if it's adequate for the task.
>>
>> Indeed, yet one is left to wonder why Thomson decided to do it this
>> way. Do they believe it's stronger than it's forged competitor?
>>
>> -Nate
>
>Cost. It's cheaper than making forgiing dies.
>Phil brown

And, to be honest, it's probably adequate. There is such a thing as
engineering overkill; Mecedes-Benz is infamous for it.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[jim beam]

philcycles wrote:
> Llatikcuf wrote:
>
>>Werehatrack wrote:
>>
>>>Thomson's choice of method is still superior to making the part from a
>>>casting, however, and their reputation is pretty good. Since you don't
>>>have the option of getting a Thomson stem that's forged, the important
>>>question is not whether their choice of method is the best possible,
>>>but rather if it's adequate for the task.
>>
>>Indeed, yet one is left to wonder why Thomson decided to do it this
>>way. Do they believe it's stronger than it's forged competitor?
>>
>>-Nate
>
>
> Cost. It's cheaper than making forgiing dies.
> Phil brown
>
for small quantity, yes. for big productions runs, it works the other
way. forged is usually better.

 

[Dave Larrington]

In article <[email protected]>, Werehatrack
([email protected]) wrote:

> And, to be honest, it's probably adequate. There is such a thing as
> engineering overkill; Mecedes-Benz is infamous for it.

s/is/was They decided that it was costing too much and started making
substantial chunks of their motorcars from cheese. They started to
exhibit un-Mercedes-like tendencies, like breaking down and wearing out
when they'd not even done 200,000 km!

To say that the collected taxi drivers of the German-speaking world were
incandescent would be something of an understatement. I am given to
understand that the latest E-Class is once more milled from solid.

--
Dave Larrington - <http://www.legslarry.beerdrinkers.co.uk/>
Pepperoni and green peppers, mushrooms, olives, chives!

 

[[email protected]]

philcycles wrote:
> Llatikcuf wrote:
> > Werehatrack wrote:
> > > Thomson's choice of method is still superior to making the part from a
> > > casting, however, and their reputation is pretty good. Since you don't
> > > have the option of getting a Thomson stem that's forged, the important
> > > question is not whether their choice of method is the best possible,
> > > but rather if it's adequate for the task.
> >
> > Indeed, yet one is left to wonder why Thomson decided to do it this
> > way. Do they believe it's stronger than it's forged competitor?
> >
> > -Nate
>
> Cost. It's cheaper than making forgiing dies.
> Phil brown

Yep. And Phil Wood and Chris King and other boutique makers use the
fabulous marketing letters CNC in their advertising print and people
worship them. Never realizing boutique makers use CNC machining and
cartridge bearings in their products because they do not have the
ability to use forging and cup and cone bearings. Its a great
marketing coup for the boutique makers to convince customers that the
cheaper and easier CNC machining is superior to forging.

 

[Scott Gordo]

Llatikcuf wrote:
> Talked to the people at Thomson today about their stems, he said they
> were machined from a solid extruded block and related the idea of clay
> being pushed through a small opening. How does extruding a solid block
> of aluminum compare in strength and fatigue resistance to the item
> being forged?
>
> -Nate

That's interesting. I'd figured that it was forged and then milled
down. Doesn't that seem like the ideal solution?

/s

 

[[email protected]]

Even more fun is that so few people know exactly what CNC refers to..
last I checked a CNC hobby mill or lathe from Sherline was under $2000.

You can CNC machine your own hubs, headsets or cranks in your basement!

 

[Werehatrack]

On 26 Jan 2006 07:45:06 -0800, "Scott Gordo" <[email protected]>
wrote:

>
>Llatikcuf wrote:
>> Talked to the people at Thomson today about their stems, he said they
>> were machined from a solid extruded block and related the idea of clay
>> being pushed through a small opening. How does extruding a solid block
>> of aluminum compare in strength and fatigue resistance to the item
>> being forged?
>>
>
>That's interesting. I'd figured that it was forged and then milled
>down. Doesn't that seem like the ideal solution?

Ideal, but far more costly. Many designs and dimensions of finished
product can be produced from identical extruded stock by merely
setting up a CNC lathe and milling machines to peel them out. With
forging, each major revision or significant dimensional variant would
require a new set of dies if the process were going to produce a real
benefit. In general, the closer the forged blank can be to a finished
product, the better the end result.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Alex Rodriguez]

In article <[email protected]>,
[email protected] says...

>Indeed, yet one is left to wonder why Thomson decided to do it this
>way. Do they believe it's stronger than it's forged competitor?

It doesn't need to be stronger than a competitors stem. It only needs to be
strong enough for the task at hand.
------------
Alex

 

[Dave]

I don't believe that Chris King uses the term CNC in their advertising.
Certainly not on their website. Can you point me somewhere else?

Why are cup and cone bearings better than cartridge?

In my experience, my Chris King hubs have outperformed my Shimano
hubs by a wide margin.

 

[M-gineering]

Dave wrote:
> I don't believe that Chris King uses the term CNC in their advertising.
> Certainly not on their website. Can you point me somewhere else?
>
P3 of the catalogue I have starts with an impressive array of cnc
machinery, and of course there are the CNC hubshakers

> Why are cup and cone bearings better than cartridge?

Bigger balls for a given space, more tolerant for misalignment, less
inclined to fail catastrophically


> In my experience, my Chris King hubs have outperformed my Shimano
> hubs by a wide margin.

They bloody well should for that kind of money!

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

 

[Tim McNamara]

"Dave" <[email protected]> writes:

> I don't believe that Chris King uses the term CNC in their
> advertising. Certainly not on their website. Can you point me
> somewhere else?
>
> Why are cup and cone bearings better than cartridge?

Adjustable bearing preload, for one thing. There are cartridge
bearings that offer this- examples are seen in Maxi-CAR hubs from
France. There are people using the same bearings in those hubs for
decades, smooth as silk still. I have a Mavic 501 front hub which
also seems to had adjustable preload cartridge bearings and is the
smoothest hub I own. I've never had cause to take it apart.

> In my experience, my Chris King hubs have outperformed my Shimano
> hubs by a wide margin.

In terms of durability? I've never used Kings, but my Phil Wood hubs
have all provided excellent service. The newer FSA designs permit
bearing replacement in a couple of minutes

 

[[email protected]]

Dave who? writes:

> I don't believe that Chris King uses the term CNC in their advertising.
> Certainly not on their website. Can you point me somewhere else?

> Why are cup and cone bearings better than cartridge?

Radial cartridge bearings are made for radial loads requiring a small
axial load to prevent balldrop, the gap between balls when there is
radial clearance, the clearance that is naturally there in such
bearings. Axial preload plays havoc with these bearings especially
when a QR is closed enough to exceed the load raring of the cartridge
bearing.

> In my experience, my Chris King hubs have outperformed my Shimano
> hubs by a wide margin.

That depends on whether you are hard on QR closures or not. Shimano
angular contact cartridge head bearings are excellent. I don't
understand why Shimano doesn't also make similar snap-together angular
contact wheel bearings.

Jobst Brandt

 

[Sorni]

M-gineering wrote:

> Bigger balls for a given space

Family newsgroup, buddy.

Bill "one for the Squidster" S.

 

[Llatikcuf]

Sorni wrote:
> M-gineering wrote:
>
> > Bigger balls for a given space
>
> Family newsgroup, buddy.

Who said this was a family oriented newsgroup? Half of the time were
talking about torqing nipples, how grease packed our balls should be,
ball diameter...... Not to metion all the stuff we hear M. Wallace is
doing. Sounds pretty NC-17 to me.

-Nate

 

[Werehatrack]

On 26 Jan 2006 14:01:39 -0800, "Dave" <[email protected]> wrote:

>I don't believe that Chris King uses the term CNC in their advertising.
>Certainly not on their website. Can you point me somewhere else?

Thirty years ago, CNC milling was a relatively new, exotic and (yes,
to marketing people) "sexy" feature. Today, it's the de facto
standard for production of repeatable items. As such, there's no need
to mention it, nor anything to be gained in doing so. Even cast and
forged parts may be finished using a CNC lathe or mill; this neither
improves the former dramatically nor detracts from the qualities of
the latter. The fact that Chris King does not mention CNC processes
explicitly is not significant.

>Why are cup and cone bearings better than cartridge?

Whther the manufacturer of the assembly is still in business when the
item needs servicing or not, a cup-and-cone headset can be fitted with
new balls and returned to service as long as the cups and cones are
not damaged. If the cartridge bearing is NLA, either because the
supplier has stopped supporting it or has gone out of business, the
whole assembly is junk. No headset uses a generic cartridge bearing
TTBOMK, though some hubs do.

>In my experience, my Chris King hubs have outperformed my Shimano
>hubs by a wide margin.

In what way, and which models of each were you comparing? Factors
that are vital to one rider may be irrelevant to another.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Chalo]

[email protected] wrote:
>
> Even more fun is that so few people know exactly what CNC refers to..
> last I checked a CNC hobby mill or lathe from Sherline was under $2000.
>
> You can CNC machine your own hubs, headsets or cranks in your basement!

Not on a Sherline, you can't. You could make some sweet bike bling for
Barbie or Ken, maybe.

But you can get in the CNC game with some decent job-shop type
equipment that now retails for under $20,000. A Bridgeport-clone mill
with 2-1/2 axis control is surprisingly capable for pieces in the
bike-part size range.

The 3 axis mill I run on a daily basis has a 35" x 35" x 80" work
envelope and a 30 HP spindle motor. But one of those will set you back
$250,000 at least, not counting a place to put it.

Chalo Colina