No one seems willing to tweak the design a little, to A.) Place the rider in a more efficient riding position, and B.) Make the bike handle better when going around corners, and at extreme speeds when descending steep hills.
Thirty or more years ago all racing frames were lugged steel, built by craftsmen. There were certain restrictions on frame geometry because it was not cost effective to make lugs in a wide range of angles.
I got around this by altering the angle of the lug as I brazed the joint. (Picture right.)
I did this with the aid of a small hammer in what I describe as, "A little refined blacksmithing."
However, I was just one builder who had taught myself certain individual skills; my methods were not practical for most larger production facilities.
Today frames are either molded from carbon fiber, or they are welded steel or aluminum; there is no restriction on what angles the various elements of the frame need to be. Within what is allowed by UCI regulations that govern competition.
There is a misconception that the UCI somehow places strict restrictions on what a frame builder or manufacturer can design, and as a result are stifling innovation. This is not true.
When I built frames, although I didn’t necessarily follow what everyone else did; my bikes were being used in UCI sanctioned events, so I always designed and built within the UCI regulations.
I needed to check to see if the UCI had changed those restrictions since I retired. Yesterday I emailed the UCI in Switzerland asking for a copy of their frame specs, and was very surprised to get a prompt reply back this morning, in less than 24 hours.
As I suspected these are mostly the same set of rules that have been in place for years. I would hazard a guess that these haven’t altered since I first became interested in frame design in the late 1950s and early 1960s.
The only changes made recently were those pertaining to the cross-section of the frame tubes. I wrote about these in two articles, Part 1. on June 17, 2009 and Part 2. on June 19, 2009. The reasons for these changes I think I addressed fully in these previous articles.
However, there is no UCI rule that says head and seat angles have to be 73 degrees, or any other angle for that matter. No UCI rule that says a fork rake has to be 43 to 45mm. Which today seems to be the industry standard.
All the UCI does in this case is lay down maximum and minimum measurements between certain points on a frame.
Within what I consider these generous parameters, frame designers are free to do whatever they want.
Below is a drawing from UCIs regs; notice it is an old school level top tube frame because this drawing has been around for years. The various dimensions are marked with article numbers and these are described below the drawing.
1.3.012 A bicycle shall not measure more that 185 cm (72.75 in.) in length and 50 cm (19.081 in.) in width overall.
1.3.013 The peak of the saddle shall be a minimum of 5 cm to the rear of a vertical plane passing through the bottom bracket spindle. This only applies to road and cyclo-x bikes. Track bikes can be less as long as the nose of the saddle is not forward of the BB center.
1.3.014 The saddle support shall be horizontal. The length of the saddle shall be 24 cm minimum and 30 cm maximum. (Between 9.437 in. and 11.081 in.) Interestingly saddle length and BB height is the same; see below.)
1.3.015 Bottom Bracket Height, The distance between the bottom bracket spindle and the ground shall be between 24 cm minimum and maximum 30 cm. (Between 9.437 in. and 11.081 in.)
1.3.016 Front and rear centers. The distance between the vertical passing through the bottom bracket spindle and the front wheel spindle shall be between 54 cm minimum and 65 cm maximum (Between 21.25 in. and 25.562 in.)
The distance between the vertical passing through the bottom bracket spindle and the rear wheel spindle shall be between 35 cm minimum and maximum 50 cm. (Between 13.75 in. and 19.687 in.)
1.3.018 Wheels of the bicycle may vary in diameter between 70 cm maximum and 55 cm minimum, (Between 27.562 in. and 21.625 in.) including the tire.
For the cyclo-cross bicycle the width of the tyre (measured between the widest parts) shall not exceed 33 mm and it may not incorporate any form of spike or stud. (In other words, no mountain bike tires on cyclo-cross bikes.)
The reason for these UCI regulations is simple. They are there to ensure that no competitor has an aerodynamic or mechanical advantage over another; either by riding in a reclining position or making the bicycle itself aerodynamic beyond that which is allowed.
To be fair when Aero-bars became popular with triathletes in the late 1980s the UCI eventually sanctioned them for use in time-trials and certain track events. The only restriction placed on aero-bars is that the hands be no further than 75cm. (29.5 in.) maximum, from the center of the BB.
So there you have it; it is not the UCI who are stifling progress or restricting what the manufacturers can build; it is the manufacturers themselves either playing it safe, or cutting costs by limiting what is available.