Comments on bike fitting, custom frames & Colnago

http://www.bikesportmichigan.com/reviews/colnago.shtml

I don't know if this is a new article or not but it's new to me and I think contains some
interesting commentary on bike fit
vs. frame design.

 

"Paul Southworth" <[email protected]> wrote in message
news:u5jZ9.30749$A%[email protected]...
>
> http://www.bikesportmichigan.com/reviews/colnago.shtml
>
> I don't know if this is a new article or not but it's new to me and I think contains some
> interesting commentary on bike fit
> vs. frame design.

Looks to me that he got it wrong again: check out the saddle. Shoved all the way forward on the
rails, 130mm stem, etc. Tells me something still ain't right.

Then again, I haven't seen the guy riding it, so I may be off.

Anyone else?

Mike

 

"Paul Southworth" <[email protected]> wrote in message
news:u5jZ9.30749$A%[email protected]...
>
> http://www.bikesportmichigan.com/reviews/colnago.shtml
>
> I don't know if this is a new article or not but it's new to me and I think contains some
> interesting commentary on bike fit
> vs. frame design.

I read this article a while ago and as a Colnago Dream owner was interested to say the least.
Also having read the fitting philosophy by Rivendell I am starting to get a bit confused ! My
Colnago is the 53cm c-c compared to this ones 51cm c-c, and as I am only 5' 6'' then I am
starting to think my bike is too big ! But who knows, anyone else got an opinion on this one ?

Graham

 

On 1/27/03 18:16, in article u5jZ9.30749$A%[email protected], "Paul Southworth"
<[email protected]> wrote:

>
> http://www.bikesportmichigan.com/reviews/colnago.shtml
>
> I don't know if this is a new article or not but it's new to me and I think contains some
> interesting commentary on bike fit
> vs. frame design.

My reaction:

I am a little skeptical that getting a frame 1cm too large makes the incredible difference in
handling that he experienced. It would be interesting to put him on two identical frames 1cm apart
and see if he can tell the difference. I don't think I could, but who knows? If anybody wants to
contribute a pair of Colnagos to the effort, I'll do my best to test them ;-)

I also am very skeptical at anybody who claims that integrated headsets are such an advance. I
generally find that properly installed and adjusted quality headsets on road bikes are already
maintenance free. I don't like the idea of buying a new frame if somehow the integrated headset
is damaged.

The only personal, albeit second hand, experience I have with such bikes is an uncle who has ridden
Colnagos for many years. He got a custom Seven, built to his fit specs, as this article does not
favor, and loves the ride of the Seven, rides it much, much more than he ever did his Colnagos.

Fit to me has to do with building the frame so the rider can put the saddle and handlebars where it
is comfortable for him/her. The handling qualities of the frame will be determined mainly by the
steering geometry, weight distribution and center of gravity. For a given saddle/handlebar position,
it seems to me that you can build frames with very significant variance in the factors that
determine handling. I think the author's contention that you should avoid a custom built frame
because the one that was built for him happened to not handle the way he wanted it is rather
illogical, any more than he should have avoided Colnago frames in the future because he was not
happy with the first one that he got.

I also find it unimpressive that such an expensive frame would come with rough surfaces from the
factory. If I were building such high $$$ frames, I would not be relying on individual dealers to
have frame prep tools and to use them on all of my frames.

Baird

--
Baird Webel Washington DC

 

All of this raises a new question for me. As frames have changed -- more seat tube extension above
the top tube, extended head tubes for threadless systems, and especially longer top tubes -- and as
the pro peloton has moved to smaller and smaller frames, what are the "experts" now saying about
formulas for bike fit? For years I have relied on the LeMond/Hinault method of .67 of inseam length
for minimum c/t size. Does this formula still hold or has the multiplier now gone down or become
irrelevant?

I realize that the formula does still hold -- bike sizes figured this way do fit. My question is
that for the more "contemporary" theorizers, do they now see this formula as "out of date?" The
original post could be interpreted as suggesting just that.

Dick Peterson

"Baird Webel" <[email protected]> wrote in message news:BA5BE229.1A5F1%[email protected]...
> On 1/27/03 18:16, in article
u5jZ9.30749$A%[email protected],
> "Paul Southworth" <[email protected]> wrote:
>
> >
> > http://www.bikesportmichigan.com/reviews/colnago.shtml
> >
> > I don't know if this is a new article or not but it's new to me and I think contains some
> > interesting commentary on bike fit
> > vs. frame design.
>
> My reaction:
>
> I am a little skeptical that getting a frame 1cm too large makes the incredible difference in
> handling that he experienced. It would be interesting to put him on two identical frames 1cm apart
> and see if he can tell the difference. I don't think I could, but who knows? If anybody wants to
> contribute a pair of Colnagos to the effort, I'll do my best to test them ;-)
>
> I also am very skeptical at anybody who claims that integrated headsets
are
> such an advance. I generally find that properly installed and adjusted quality headsets on road
> bikes are already maintenance free. I don't like the idea of buying a new frame if somehow the
> integrated headset is
damaged.
>
> The only personal, albeit second hand, experience I have with such bikes
is
> an uncle who has ridden Colnagos for many years. He got a custom Seven, built to his fit specs, as
> this article does not favor, and loves the ride of the Seven, rides it much, much more than he
> ever did his Colnagos.
>
> Fit to me has to do with building the frame so the rider can put the
saddle
> and handlebars where it is comfortable for him/her. The handling
qualities
> of the frame will be determined mainly by the steering geometry, weight distribution and center of
> gravity. For a given saddle/handlebar
position,
> it seems to me that you can build frames with very significant variance in the factors that
> determine handling. I think the author's contention that you should avoid a custom built frame
> because the one that was built for
him
> happened to not handle the way he wanted it is rather illogical, any more than he should have
> avoided Colnago frames in the future because he was
not
> happy with the first one that he got.
>
> I also find it unimpressive that such an expensive frame would come with rough surfaces from the
> factory. If I were building such high $$$ frames,
I
> would not be relying on individual dealers to have frame prep tools and to use them on all of
> my frames.
>
> Baird
>
>
>
>
> --
> Baird Webel Washington DC

 

R J Peterson wrote:
> All of this raises a new question for me. As frames have changed -- more seat tube extension above
> the top tube, extended head tubes for threadless systems, and especially longer top tubes -- and
> as the pro peloton has moved to smaller and smaller frames, what are the "experts" now saying
> about formulas for bike fit? For years I have relied on the LeMond/Hinault method of .67 of inseam
> length for minimum c/t size. Does this formula still hold or has the multiplier now gone down or
> become irrelevant?
>
> I realize that the formula does still hold -- bike sizes figured this way do fit. My question is
> that for the more "contemporary" theorizers, do they now see this formula as "out of date?" The
> original post could be interpreted as suggesting just that.
>
> Dick Peterson

What's out of date is the idea that the seat tube length tells you what size the bike is. Back in
the level top-tube, lugged-frame era, frame geometry was more standardized, Only very expensive
frames offered different top tube lengths for different sizes, so we all got into the habit of
thinking of the seat tube length as being the key index of a frame's size.

The fact is, however, that with modern frame designs, the seat tube length is one of the least
important dimensions. Sure, it has to be short enough to provide appropriate standover height, but
that's it! After all, the seat post is _adjustable_!

There are two very much more important dimensions that determine fit: top tube length and seat
tube angle.

If you get these right, you're on the basically right size frame, however much seatpost is
sticking out.

See also http://sheldonbrown.com/frame-sizing.html

Other dimensions will affect the riding/handling characteristics of the bike, and if you're
short-legged, you may have standover clearance issues on a stock frame, but those two dimensions are
the primary determinants of whether the bike "fits" or not.

Sheldon "Seat-Tube Size Is Not Important" Brown
+------------------------------------------------------------+
| It is one thing to show a man that he is in an error, | and another to put him in possession of
| truth. | --John Locke |
+------------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
shipped Worldwide http://captainbike.com http://sheldonbrown.com

 

In article <[email protected]>, Sheldon Brown <[email protected]> wrote:
>
>There are two very much more important dimensions that determine fit: top tube length and seat
>tube angle.

In addition I would say that head tube length is also more important than seat tube length on modern
bikes - it is highly variable when comparing sloping designs from different manufacturers and has
more impact on fit and position than the seat tube length.

 

On Tue, 28 Jan 2003 11:23:18 -0500, Sheldon Brown wrote:

> The fact is, however, that with modern frame designs, the seat tube length is one of the least
> important dimensions. Sure, it has to be short enough to provide appropriate standover height, but
> that's it! After all, the seat post is _adjustable_!
>
> There are two very much more important dimensions that determine fit: top tube length and seat
> tube angle.

Excellent points. But, what of the seat tube angle is about "size"? I could see it affecting the
rider's relative position on the bike, but that more reflects the type of use (time-trials -vs-
loaded touring, for example) than the fit.

--

David L. Johnson

__o | A mathematician is a machine for turning coffee into theorems. _`\(,_ | -- Paul Erdos
(_)/ (_) |

 

I asserted:

>>There are two very much more important dimensions that determine fit: top tube length and seat
>>tube angle.

Paul Southworth wrote:

> In addition I would say that head tube length is also more important than seat tube length on
> modern bikes - it is highly variable when comparing sloping designs from different manufacturers
> and has more impact on fit and position than the seat tube length.

I agree that it is more important than seat tube length, but still less important than the top tube
length or seat angle. There are always ways to get the handlebars up higher (though perhaps not
always aesthetically pleasing ways.) Nobody ever wants them lower.

Sheldon "Priorities" Brown +-----------------------------------+
| Habit is the nursery of errors. | --Victor Hugo |
+-----------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone 617-244-9772
FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

 

Paul Southworth <[email protected]> wrote:

> http://www.bikesportmichigan.com/reviews/colnago.shtml

> I don't know if this is a new article or not but it's new to me and I think contains some
> interesting commentary on bike fit
> vs. frame design.

Sounds like a lot of BS.

Art Harris

 

I said:

>>The fact is, however, that with modern frame designs, the seat tube length is one of the least
>>important dimensions. Sure, it has to be short enough to provide appropriate standover height, but
>>that's it! After all, the seat post is _adjustable_!
>>
>>There are two very much more important dimensions that determine fit: top tube length and seat
>>tube angle.

David L. Johnson asked:

> Excellent points. But, what of the seat tube angle is about "size"? I could see it affecting the
> rider's relative position on the bike, but that more reflects the type of use (time-trials -vs-
> loaded touring, for example) than the fit.

It is about fit, not specifially about size. Seat tube angle interacts with top tube length.
Optimally, the seat tube angle should probably be related to the riders femur length ("Q" factor in
FitKit terminology.)

A bike with a more upright seat angle generally calls for a shorter top tube, for a given riding
style, as the rider will likely move the saddle farther back than would be the case with a more
laid-back frame.

Sheldon "Likes Shallow Seat Tube Angles" Brown +-------------------------------------------+
| To escape criticism -- | do nothing, say nothing, be nothing. | --Elbert Hubbard |
+-------------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

 

"David L. Johnson" <David L. Johnson <[email protected]>> wrote:

> Excellent points. But, what of the seat tube angle is about "size"? I could see it affecting the
> rider's relative position on the bike, but that more reflects the type of use (time-trials -vs-
> loaded touring, for example) than the fit.

The seat tube angle is very relevant, because without knowing it the top tube length alone doesn't
say much. For example, lets take two "55 cm" frames with the same top tube length, for example 54
centimetres. If the frames have different seat tube angles, for example 72 and 74 degrees, in the
frame with a 72-degree seat tube angle the top tube connects to the seat tube 18 millimetres further
behind the bottom bracket than in the frame with a 74-degree seat tube angle. In effect the top tube
is 18 millimetres shorter, because the saddle is always (or should always be) positioned relative to
the bottom bracket and the pedals.

In practice frames with longer top tubes also often have shallower seat tube angles, so the
real-life difference might be non-existent, even if the top tube on the frame is 15 or 20
millimetres longer than on a frame like a Colnago.

-as

 

The author's worshipful adoration of the Colnago brand is annoying, masturbatory and mistaken in its
belief in the singular quality of their bikes. Hey, Ernesto, the paint is FUGLY!

His commentary implies/professes the universal truth of the superiority of Colnago for
anyone. So wrong.

App

[email protected] (Paul Southworth) wrote in message
news:<u5jZ9.30749$A%[email protected]>...
> http://www.bikesportmichigan.com/reviews/colnago.shtml
>
> I don't know if this is a new article or not but it's new to me and I think contains some
> interesting commentary on bike fit
> vs. frame design.

 

>From: [email protected]

>Hey, Ernesto, the paint is FUGLY!

A friend of mine said if pimps rode bikes instead of Cadillacs, they'd be on Colnagos. Wonder if
Vogue makes bicycle tires?

Sig Chicago

 

<< > http://www.bikesportmichigan.com/reviews/colnago.shtml
> I don't know if this is a new article or not but it's new to me and I think contains some
> interesting commentary on bike fit
> vs. frame design >>

The author says: " I didn't have the standover height I needed for aggressive accelerations and
climbing."

What does this mean?

 

Sheldon Brown <[email protected]> wrote:

>There are two very much more important dimensions that determine fit: top tube length and seat
>tube angle.

To try to clarify what others have said, and to (I think) clarify what you said...

They said: Seat tube angle by itself really doesn't affect fit (since saddles can be moved enough to
provide proper fit over the typical - narrow - range of seat tube angles on most road bikes). One
whole degree of seat tube change induces an apparent 1cm or so change in effective top tube length.

Sheldon said: The COMBINATION of top tube length and seat tube angle is the more important
dimension.

Or at least that's how I interpret the two sides of this.

>If you get these right, you're on the basically right size frame, however much seatpost is
>sticking out.

I tend to break down fit issues into more basic components:

Cockpit length and handlebar height. Factor in bottom bracket height and drop to the bars from the
saddle (to correct for handlebar height) and you have the ability to determine how (or if) to fit a
particular rider to a particular bike. If the customer is looking for the bars at nearly the height
of the top of the saddle, a frame with a lot of seatpost showing isn't going to get there...

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame

 

[email protected] (Mike Krueger) wrote:

><< > http://www.bikesportmichigan.com/reviews/colnago.shtml
>> I don't know if this is a new article or not but it's new to me and I think contains some
>> interesting commentary on bike fit
>> vs. frame design >>
>
>The author says: " I didn't have the standover height I needed for aggressive accelerations and
>climbing."
>
>What does this mean?

Obviously he's using 290mm cranks. He's banging Mr. Happy on the top tube on the downstroke
apparently.

The bike must have a really high BB shell!

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame

 

"Mark Hickey" <[email protected]> wrote in message
news:[email protected]...
> [email protected] (Mike Krueger) wrote:
>
> ><< > http://www.bikesportmichigan.com/reviews/colnago.shtml
> >> I don't know if this is a new article or not but it's new to me and I think contains some
> >> interesting commentary on bike fit
> >> vs. frame design >>
> >
> >The author says: " I didn't have the standover height I needed for aggressive
accelerations and
> >climbing."
> >
> >What does this mean?
>
> Obviously he's using 290mm cranks. He's banging Mr. Happy on the top tube on the downstroke
> apparently.
>
> The bike must have a really high BB shell!

Does anyone detect a faint whiff of "Road Bike Action" in that site's reviews? But then no actual
expertise is required to share your opinions online, so... ;-)

 

I have a Gilmour that I bought secondhand with a 72.5 seat angle, a 54.5cm tt. I can't get my
position right without moving the saddle all the way forward (with a Syncros post!) Oops! Guess I
should've looked into that first...

My other bike is a Specialized M4 with a steeper st angle and a 54cm tt. This one fits without
resorting to moving my saddle back all the way.

I've figured out that I need somewhere between a 73 and 74 degree seat angle and a 54-54.5cm tt to
have the right fit. Any angles slacker than that and I can't get my position right.

So, my point is that even though at first glance the Gilmour looked like it'd fit based on tt
length, the slack st angle made it the wrong bike for
me. Its for sale btw... gotta find something that fits right for racing.

Mike

"Antti Salonen" <[email protected]> wrote in message
news:[email protected]...
> "David L. Johnson" <David L. Johnson <[email protected]>> wrote:
>
> > Excellent points. But, what of the seat tube angle is about "size"? I could see it affecting the
> > rider's relative position on the bike, but that more reflects the type of use (time-trials -vs-
> > loaded touring, for example) than the fit.
>
> The seat tube angle is very relevant, because without knowing it the top tube length alone doesn't
> say much. For example, lets take two "55 cm" frames with the same top tube length, for example 54
> centimetres. If the frames have different seat tube angles, for example 72 and 74 degrees, in the
> frame with a 72-degree seat tube angle the top tube connects to the seat tube 18 millimetres
> further behind the bottom bracket than in the frame with a 74-degree seat tube angle. In effect
> the top tube is 18 millimetres shorter, because the saddle is always (or should always be)
> positioned relative to the bottom bracket and the
pedals.
>
> In practice frames with longer top tubes also often have shallower seat tube angles, so the
> real-life difference might be non-existent, even if the top tube on the frame is 15 or 20
> millimetres longer than on a frame like a Colnago.
>
> -as

 

> Looks to me that he got it wrong again: check out the saddle. Shoved all the way forward on the
> rails, 130mm stem, etc. Tells me something still ain't right.

The guy does spout a lot of BS such as the bit about the higher centre of gravity of the larger
frame making a difference. Let's see, the frame was 1cm bigger, so the c. of g. of the frame alone
must have moved up by 5mm or so. The seat, post, bars, stem drivetrain etc. must have all been in
the same place and they are 80% of the weight of the bike, so the c. of g. of the total bike must
have moved up by about
1mm. And he says he can feel the difference?

On the other hand there is a grain of truth in what he says about fitting Colnagos. Modern Colnagos
are designed with slack head tube angles (generally 72.5) and higher levels of fork rake. This has
the effect that for a given wheelbase the top tube has to be shorter, however to get the handlebars
in the same place relative to the front axle the stem needs to be slightly longer. This is why
people who say that Colnago top tubes are too short are missing something, it is the top
tube/headtube angle/stem length relationship that needs to be looked at.

I do agree with his point that some cyclists want a custom bike made with specific measurements
without a full understanding of the design of the entire bike, to the detriment of the finished
product. Colnagos have an unusual design that works well because all of the elements have been
considered together, if you start to mess around with these it is unlikely you will come up with a
superior bike.