Is there supposed to be an advantage to Compact Frame Geometry?

[Colin Campbell]

I don't like the look of the compact frames, and my cynical take on them
is that manufacturers like them because it reduces the number of frame
sizes they need to make.

A compact frame is likely a bit lighter than a "standard" frame, but
doesn't the extra long seat post negate most of that advantage?

 

[Kurd]

"Colin Campbell" <[email protected]> wrote in message
news:[email protected]...
> I don't like the look of the compact frames, and my cynical take on them
> is that manufacturers like them because it reduces the number of frame
> sizes they need to make.
>
> A compact frame is likely a bit lighter than a "standard" frame, but
> doesn't the extra long seat post negate most of that advantage?

Fewer sizes is nicer for shops and manufactuers alike and lower standover
height is better for me personally (29" pants inseam, 57cm frame). Other
than that, no, no real advantage.

 

[Tim McNamara]

In article <[email protected]>,
Colin Campbell <[email protected]> wrote:

> I don't like the look of the compact frames, and my cynical take on
> them is that manufacturers like them because it reduces the number of
> frame sizes they need to make.
>
> A compact frame is likely a bit lighter than a "standard" frame, but
> doesn't the extra long seat post negate most of that advantage?

Well, it works for mountain bikes. My hunch is that this was the
inspiration. Back when Giant started marketing these frames, they
claimed that a family could buy a high quality bike for Junior or
Juniorette, and keep it through several growth spurts by just swapping
out the seatpost and stem.

 

[sally]

Colin Campbell <[email protected]> wrote in
news:[email protected]:
> A compact frame is likely a bit lighter than a "standard" frame, but
> doesn't the extra long seat post negate most of that advantage?

Yes.

The main advantage of compact frames is greater standover height in small
frame sizes, potentially giving shorter people more fit options.
Unfortunately, some manufacturers negate this advantage by selling
compact frames in fewer sizes than standard geometry frames.

 

[* * Chas]

"Colin Campbell" <[email protected]> wrote in message
news:[email protected]...
> I don't like the look of the compact frames, and my cynical take on
them
> is that manufacturers like them because it reduces the number of frame
> sizes they need to make.
>
> A compact frame is likely a bit lighter than a "standard" frame, but
> doesn't the extra long seat post negate most of that advantage?

Inseam length is the most critical issue in frame size but many racers
have ridden compact frames in competition over the years.

At various times compact frames have been popular because they are
slightly stiffer due to shorter tubes which is beneficial especially in
short duration competition like track racing, criteriums and time
trials.

With the advent of mountain bikes, high bottom bracket height and the
ability to quickly dismount without risking injury to personal areas
made compact frames very practical.

Sloping top tubes help because the standover height in front of the seat
is lower plus longer steering tubes allow bars to higher without a super
long stem.

Larger frames can be more comfortable for longer rides like touring and
road racing because they are generally more flexible and will absorb
more road shock.

We used to import cyclo-cross bikes and sell them for touring before
specialized touring frames were commonly available. They worked great
for touring bikes with cantilever brakes, long wheel bases and relaxed
angles.

Interestly, at the time most Interestingly-cross riders used larger
frames even though they had to frequently dismount under less than ideal
circumstances.

Cycling throughout it's history has been influenced by what ever is in
vogue more than perhaps any other sport. Many cyclist have to have
whatever the hottest celebrities are riding.

The most important things is to have a frame that fits your needs.

Chas.

 

[RonSonic]

On Mon, 17 Jul 2006 02:52:50 -0700, "* * Chas" <[email protected]> wrote:

>
>"Colin Campbell" <[email protected]> wrote in message
>news:[email protected]...
>> I don't like the look of the compact frames, and my cynical take on
>them
>> is that manufacturers like them because it reduces the number of frame
>> sizes they need to make.
>>
>> A compact frame is likely a bit lighter than a "standard" frame, but
>> doesn't the extra long seat post negate most of that advantage?
>
>Inseam length is the most critical issue in frame size but many racers
>have ridden compact frames in competition over the years.
>
>At various times compact frames have been popular because they are
>slightly stiffer due to shorter tubes which is beneficial especially in
>short duration competition like track racing, criteriums and time
>trials.
>
>With the advent of mountain bikes, high bottom bracket height and the
>ability to quickly dismount without risking injury to personal areas
>made compact frames very practical.
>
>Sloping top tubes help because the standover height in front of the seat
>is lower plus longer steering tubes allow bars to higher without a super
>long stem.
>
>Larger frames can be more comfortable for longer rides like touring and
>road racing because they are generally more flexible and will absorb
>more road shock.
>
>We used to import cyclo-cross bikes and sell them for touring before
>specialized touring frames were commonly available. They worked great
>for touring bikes with cantilever brakes, long wheel bases and relaxed
>angles.
>
>Interestly, at the time most Interestingly-cross riders used larger
>frames even though they had to frequently dismount under less than ideal
>circumstances.

You are finding something ironic in that? The larger frame gets the bars up
where you want them on bad terrain without a whippy stem. A compact frame with
the same height at the head tube and the typical cross BB height will have less
room for shouldering and more importantly will bring the crank up into your hip.
Larger frames also tend to be more stable on bad surfaces.

As to the lost standover height, nobody cares. That's only a factor if you're
standing still straddling the bike with a foot on either side. This is not a
position that ever occurs in a cross race.

A cross dismount is completely unaffected by the size of the bike.

Ron

 

[Qui si parla Campagnolo]

Colin Campbell wrote:
> I don't like the look of the compact frames,

Neither do I.

and my cynical take on them
> is that manufacturers like them because it reduces the number of frame
> sizes they need to make.

Not cynical at all but cost savings painted as performance...right on
the mark.
>
> A compact frame is likely a bit lighter than a "standard" frame, but
> doesn't the extra long seat post negate most of that advantage?

Not if you include the weight of the 400mm seatpost needed.

For smaller riders, that have proportional torsos, compact is a great
idea to have a proper top tube length and standover clearance. Also for
thosew that want a high, long headtube, for a really upright positoon,
extending the headtube length in effect makes a 'compact'...but the
seat cluser is not lowered. For the rest of us, it is marketing and
cost savings not passed onto the consumer. Giant needs to get an award
for painting this as 'performance' along with the ksyrium designer and
threadless HS designers.

 

[Qui si parla Campagnolo]

Kurd wrote:
> "Colin Campbell" <[email protected]> wrote in message
> news:[email protected]...
> > I don't like the look of the compact frames, and my cynical take on them
> > is that manufacturers like them because it reduces the number of frame
> > sizes they need to make.
> >
> > A compact frame is likely a bit lighter than a "standard" frame, but
> > doesn't the extra long seat post negate most of that advantage?
>
> Fewer sizes is nicer for shops and manufactuers alike

poppycock...it's like the shoe store only having shoes in whole
sizes...some may fit, some may not...I guess stuffing some tissue in
the toe. HOW compact, 4 size makers, say their bikes 'fit more
people'..well they gotta but fit fewer well.


and lower standover
> height is better for me personally (29" pants inseam, 57cm frame). Other
> than that, no, no real advantage.

 

[Qui si parla Campagnolo]

* * Chas wrote:
> "Colin Campbell" <[email protected]> wrote in message
> news:[email protected]...
> > I don't like the look of the compact frames, and my cynical take on
> them
> > is that manufacturers like them because it reduces the number of frame
> > sizes they need to make.
> >
> > A compact frame is likely a bit lighter than a "standard" frame, but
> > doesn't the extra long seat post negate most of that advantage?
>
> Inseam length is the most critical issue in frame size but many racers
> have ridden compact frames in competition over the years.
>
> At various times compact frames have been popular because they are
> slightly stiffer due to shorter tubes which is beneficial especially in
> short duration competition like track racing, criteriums and time
> trials.
>
> With the advent of mountain bikes, high bottom bracket height and the
> ability to quickly dismount without risking injury to personal areas
> made compact frames very practical.
>
> Sloping top tubes help because the standover height in front of the seat
> is lower plus longer steering tubes allow bars to higher without a super
> long stem.
>
> Larger frames can be more comfortable for longer rides like touring and
> road racing because they are generally more flexible and will absorb
> more road shock.
>
> We used to import cyclo-cross bikes and sell them for touring before
> specialized touring frames were commonly available. They worked great
> for touring bikes with cantilever brakes, long wheel bases and relaxed
> angles.
>
> Interestly, at the time most Interestingly-cross riders used larger
> frames even though they had to frequently dismount under less than ideal
> circumstances.
>
> Cycling throughout it's history has been influenced by what ever is in
> vogue more than perhaps any other sport. Many cyclist have to have
> whatever the hottest celebrities are riding.
>
> The most important things is to have a frame that fits your needs.
>
> Chas.

Wait a minute-you say-
"At various times compact frames have been popular because they are
> slightly stiffer due to shorter tubes which is beneficial especially in
> short duration competition like track racing, criteriums and time
> trials.

And then ya say-
" Larger frames can be more comfortable for longer rides like touring
and
> road racing because they are generally more flexible and will absorb
> more road shock.

????

Compact is for the manufacturters to save $ with fewer
SKUs...period...smaller sizes have always been compact...

 

[RonSonic]

On 17 Jul 2006 05:42:21 -0700, "Qui si parla Campagnolo" <[email protected]>
wrote:

>
>Kurd wrote:
>> "Colin Campbell" <[email protected]> wrote in message
>> news:[email protected]...
>> > I don't like the look of the compact frames, and my cynical take on them
>> > is that manufacturers like them because it reduces the number of frame
>> > sizes they need to make.
>> >
>> > A compact frame is likely a bit lighter than a "standard" frame, but
>> > doesn't the extra long seat post negate most of that advantage?
>>
>> Fewer sizes is nicer for shops and manufactuers alike
>
>poppycock...it's like the shoe store only having shoes in whole
>sizes...some may fit, some may not...I guess stuffing some tissue in
>the toe. HOW compact, 4 size makers, say their bikes 'fit more
>people'..well they gotta but fit fewer well.

Like helmets, the ones that are advertised as "one size fits all" don't fit.

Ron

 

[John Thompson]

On 2006-07-17, sally <[email protected]> wrote:

> The main advantage of compact frames is greater standover height in small
> frame sizes, potentially giving shorter people more fit options.
> Unfortunately, some manufacturers negate this advantage by selling
> compact frames in fewer sizes than standard geometry frames.

Yup. Seat tube length isn't the only that should change for different
size riders. Taller riders tend to have longer torsos, and so the top
tube length should change as well. This can be cobbled up to fit in the
same way compact frames fit a variety of riders by using long seat
posts: different stem extension lengths can address this to some extent,
but it's not the same as having a bike that fits.

--

John ([email protected])

 

[SMS]

Colin Campbell wrote:
> I don't like the look of the compact frames, and my cynical take on them
> is that manufacturers like them because it reduces the number of frame
> sizes they need to make.
>
> A compact frame is likely a bit lighter than a "standard" frame, but
> doesn't the extra long seat post negate most of that advantage?

The advantage is to manufacturers in terms of reduced material cost,
fewer frame size SKUs, and slightly lower shipping costs.

Like many so-called advances, the manufacturer comes up with
rationalizations, after the fact, to try to justify what they do.

There was a very good article about compact geometry frames on the
Cannondale web site at which stated: "there's a disturbing trend among
some bike companies to re-tool their road frames by shortening the seat
tube and slanting the top tube down from the head tube. This new design
"breakthrough," they argue, saves frame weight. And if you take their
claim literally, they're right - a shorter seat tube does make a bare
frame a little lighter. What they don't tell you is that their complete
bicycle actually weighs more than a bike with a conventional geometry.
Why? You have to use longer (and therefore heavier) seatposts and stems
on smaller frames to fit the rider properly, and their added weight more
than off-sets the few grams saved by their sloping top tube frames."

From "http://bicycleshortlist.com" "While an aluminum frame and a
threadless headset may not be the best choices, they are not all that
terrible, and the cost savings over the alternatives are significant.
But a compact frame is very undesirable, and the cost savings are NOT
worth it. Whatever you do, avoid compact frames on road bikes. Get a
properly sized, "traditional" geometry frame."

 

[amakyonin]

Qui si parla Campagnolo wrote:

> Compact is for the manufacturters to save $ with fewer
> SKUs...period...smaller sizes have always been compact...

Every time you harp on this you make it seem as if compact geometry
(CG) is inherently inferior. While it can have some cost advantages for
the manufacturer, compact geometry also has advantages for many riders.

Some manufacturers build compact frames in a full range of sizes in
~2cm increments, not just S, M, and L. These guys aren't enjoying any
cost reductions from a reduced product range. That leaves their
motivating factor to one of either trendiness or the fact the CG
actually has some benefits. Offering only three sizes is certainly
going to leave some riders with a poor fit but that has nothing to do
with the suitability CG itself. CG is only an enabling factor in a
manufacturer's decision to offer only three sizes.

Obviousy, CG makes it possible to fit (or shoehorn) a particular frame
to a broader range of riders and an LBS could get away with carrying
less inventory and maintain sales volume. If anything, this is a
win-win for everybody provided the frame is a good fit for the rider.
If a full range of sizes is in production, you still have the
opportunity to order the right size if the LBS doesn't have what you
need in stock. Again, just because some CG bikes are sized with the
shoehorn approach in mind doesn't invalidate the other advantages
conferred by CG.

I ride a 58cm compact frame that gives me the top tube length I desire
while still being able to get stand over clearance. With traditional
geometry I'd have to settle for a smaller frame with a shorter top tube
and a longer stem to compensate.

 

[David Damerell]

Quoting SMS <[email protected]>:
> From "http://bicycleshortlist.com" "While an aluminum frame and a
>threadless headset may not be the best choices, they are not all that
>terrible, and the cost savings over the alternatives are significant.

Classic Scharfism; an unwary reader might get the impression you aren't
just quoting yourself.
--
David Damerell <[email protected]> flcl?
Today is Gorgonzoladay, Presuary - a weekend.

 

[* * Chas]

"SMS" <[email protected]> wrote in message
news:[email protected]...
> Colin Campbell wrote:
> > I don't like the look of the compact frames, and my cynical take on
them
> > is that manufacturers like them because it reduces the number of
frame
> > sizes they need to make.
> >
> > A compact frame is likely a bit lighter than a "standard" frame, but
> > doesn't the extra long seat post negate most of that advantage?
>
> The advantage is to manufacturers in terms of reduced material cost,
> fewer frame size SKUs, and slightly lower shipping costs.
>
<snip>

Except for very long tubes for extra large frames, the cost difference
in tubing length for metal frames is nil. Metal frame manufacturers buy
butted tubes in standard lengths and cut them to fit their needs. In the
US straight gage tubing is usually purchased in 20' sections and cut
them off to required lengths.

The cost of carbon fiber and other composite materials are different and
depend on manufacturing techniques used by the builder.

Inventory costs is another issue....

Chas.

 

[waxbytes]

I have short (relative to my torso) legs. It wasn't until compact frames that I could get a bicycle that I could ride comfortably and still stand over without singing falsetto. I like the look of traditional geometry but compact framing has won my vote, for strictly fit reasons. As far as stiffness and weight go I don't think the differences are significant comparing bikes of same make and material similarly equipped. The number of size increments made in a model of bicycle is a manufacturing decision and has little or nothing to to with the merits of any particular frame design.

 

[Kurd]

"Qui si parla Campagnolo" <[email protected]> wrote in message
news:[email protected]...
>
> poppycock...it's like the shoe store only having shoes in whole
> sizes...some may fit, some may not...I guess stuffing some tissue in
> the toe. HOW compact, 4 size makers, say their bikes 'fit more
> people'..well they gotta but fit fewer well.
>

I agree that it's not nessessarily better for the customers to only have 4
sizes. It's a calculated loss for the manufactuer and the dealer to only
have to worry about 4 or 5 sizes. Lower inventory and fewer SKUs make most
dealers happy. Very similar comparison to shoes.

 

[Michael Press]

In article <[email protected]>,
John Thompson <[email protected]> wrote:

> On 2006-07-17, sally <[email protected]> wrote:
>
> > The main advantage of compact frames is greater standover height in small
> > frame sizes, potentially giving shorter people more fit options.
> > Unfortunately, some manufacturers negate this advantage by selling
> > compact frames in fewer sizes than standard geometry frames.
>
> Yup. Seat tube length isn't the only that should change for different
> size riders. Taller riders tend to have longer torsos, and so the top
> tube length should change as well. This can be cobbled up to fit in the
> same way compact frames fit a variety of riders by using long seat
> posts: different stem extension lengths can address this to some extent,
> but it's not the same as having a bike that fits.

<http://www.ulrikchristensen.dk/scripts/montypython/terrier.html>

--
Michael Press

 

[Michael Press]

In article
<[email protected]>,
"* * Chas" <[email protected]> wrote:

> At various times compact frames have been popular because they are
> slightly stiffer due to shorter tubes which is beneficial especially in
> short duration competition like track racing, criteriums and time
> trials.

I want to see documentation for this, because I do not
think compact frames are stiffer. What a rider sees as
stiffness is reduced flex at the bottom bracket under high
pedal forces. This is almost entirely a function of the
joints at the bottom bracket, particularly to the chain
stays.

--
Michael Press

 

[Mark Hickey]

"Ron Ruff" <[email protected]> wrote:

>SMS wrote:
>> But a compact frame is very undesirable, and the cost savings are NOT
>> worth it. Whatever you do, avoid compact frames on road bikes. Get a
>> properly sized, "traditional" geometry frame."
>
>Duh... yet another ridiculous religious argument about compact frames.
>
>The Cannondale quote is silly. Compact frames don't require longer
>stems. They do require a longer post, though... but the added weight of
>that ends up being slightly less than the lower weight of top tube,
>seat tube, and seatstays... all of which get shorter.

Ahhh, but the seat tube/top tube/seat stay junction has to be stronger
than on a traditional frame to handle the longer lever-arm of the
longer (heavier) seat tube. Hence, the compact frame either uses the
same tubes and is weaker in this area (relative to the forces
produced) or uses heavier tubes and is as strong (also negating any
miniscule weight reduction).

>So what is so bad about compact? It isn't "better" in performance, but
>it isn't worse either... and riders with shorter legs can get some
>crotch clearance.

That's pretty much the bottom line. Sometimes I like to point out
that a sloping top tube is less aerodynamic than a horizontal one, but
I won't do that here. ;-)

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame