On 4/28/2012 8:53 AM, Lou Holtman wrote:
Op 28-4-2012 11:54, SMS schreef:
On 4/28/2012 2:03 AM, Lou Holtman wrote:

The toptube is also slightly sloped. Some people qualify that as
'wrecked' and limiting their choice enormously.

Lou

I'm sure that you are aware that the slope of the top tube is
immaterial, it's the geometry and dimensions. You can look at what
Bianchi has done by looking at how the frame has shrunk over time.

Cannondale summarized it well:

"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."

The manufacturer saves money of course. Not only does the cost of
materials go down slightly, but most manufacturers reduces the number of
size SKUs and use longer seat posts and different stems and fork
lengths. Instead of 8-10 frame sizes you can now make 5-6.

Unless the rider is very short, a the geometry of the the compact frame
does not place the rider in the optimum position for handling and
comfort.

Throw in some clever marketing catch phrases about how a compact frame
is lighter and stiffer, to justify the change, and once there are few
alternatives you leave the bike shops no choice other than to parrot the
manufacturer's marketing. Sadly, most customers do little research and
don't understand why their new bicycle is more uncomfortable, and rides
poorer than their old one.

It's especially instructive and amusing to see how the after-market
parts and accessory industry responded to compact frames.

Look at something as mundane as bottle cages. On some smaller size
frames, the manufacturer dropped one set of braze-ons because there
simply was no longer room for a second bottle. But some left the second
set of braze-ons even though there really wasn't room for the second
bottle. Cage manufacturers responded with products like
http://www.mellowveloblog.com/?p=535 " it’s perfect for those of us
who find that the small frames we ride are not well suited for carrying
two bottles. The bottoms bump into each other and the low or sloping top
bar leaves little room to remove and replace the bottles."

Seatposts are another issue. Since the seatposts are longer a lot of
riders found that with a lighter carbon seatpost there was far too much
flex so they switched to a heavier aluminum seat post. You used to
almost never hear of a broken seat post because a properly sized
standard frame has a pretty short seat post. Now you often see broken
seat posts, and there have been a slew of recalls, and not just on
carbon seat posts.

There are major disadvantages to the rider of the smaller frame, but
major advantages to the manufacturer. Sheldon Brown stated it
succinctly: "Manufacturers like compact frames because they are more
versatile in terms of fit. Usually 3 or 4 sizes are enough to fit 98% of
customers. This saves a lot of money for a manufacturer who doesn't need
to deal with so many different sizes."


As you said the slope of the TT is immaterial so IMO there is no (fit)
reasons to exclude these frames in your friends choice. The extreme
compact geometry is from the past for roadframes. 90% have slightly
sloped toptubes even Cannondale so what are they talking about:

http://www.cannondale.com/nld/2012/b...ite-road/caad8

Headtube angle 73 degree-sh, seattube angle 73 degree-ish, wheeldistance
1000 mm-ish, so it comes down to (effective) toptube length; that's it.
I have a roadbike with a horizontal TT and a roadbike with a sloping
toptube. There is no difference whatsoever between those frames fit
wise. The frame with the sloping TT comes in 7 sizes and it was easy to
find one that fits me. The only difference is headtube length. The frame
with the horizontal TT needs a more upright stem and/or more spacers.
Personally I don't really like the look of it, but it doesn't bother me
either.

https://picasaweb.google.com/101076538433373858645/SlopingVersusHorizontalTT?authkey=Gv1sRgCI2Qr-ChrNW4xwE#


Lou

Very interesting, thanks for taking the time.