X/Y Rules for cycling: After the "peer review"
Written by: Dan Empfield
Date: Mon Dec 10 2007
The nice thing about the Internet -- or the maddening thing, if you like finality -- is that there rarely is any finality. Articles that we publish are not the last word on a subject, they're typically the first word.
A case in point is the article written last week on X/Y rules in an angular world. That caused a lively and instructive discussion on our reader forum, during which several improvements and enhancements were suggested. One person wisely offereed incorporating the saddle length restrictions into the rule. It was a brilliant idea and suggested text for the rule was generated. It was then a simple matter to alter the measuring jig used by a commissaire to account for this rule enhancement.
The suggested rule text is as follows, and would replace the text currently serving as rule 1.3.013 in the ITU rulebook:
"The nose of the saddle shall protrude no further forward than 18 centimeters in front of a line passing through the bottom bracket spindle and inclined rearward at an angle of 78 degrees from the horizontal."
The rule as suggested uses 78 degrees as the reference angle. The rule can read anything from 75 degrees to 81 degrees, depending on what the UCI thinks is most appropriate. The point, in any case, is that the rule would now be fair, and would not discriminate against shorter riders and against women, as it now does. I chose 78 degrees because it is midway between the shallowest and steepest seat angles riders adopt when they're able to choose a seat angle optimize for them during a timed event.
A case in point is the article written last week on X/Y rules in an angular world. That caused a lively and instructive discussion on our reader forum, during which several improvements and enhancements were suggested. One person wisely offereed incorporating the saddle length restrictions into the rule. It was a brilliant idea and suggested text for the rule was generated. It was then a simple matter to alter the measuring jig used by a commissaire to account for this rule enhancement.
The suggested rule text is as follows, and would replace the text currently serving as rule 1.3.013 in the ITU rulebook:
"The nose of the saddle shall protrude no further forward than 18 centimeters in front of a line passing through the bottom bracket spindle and inclined rearward at an angle of 78 degrees from the horizontal."
The rule as suggested uses 78 degrees as the reference angle. The rule can read anything from 75 degrees to 81 degrees, depending on what the UCI thinks is most appropriate. The point, in any case, is that the rule would now be fair, and would not discriminate against shorter riders and against women, as it now does. I chose 78 degrees because it is midway between the shallowest and steepest seat angles riders adopt when they're able to choose a seat angle optimize for them during a timed event.
The rule not only injects fairness into the UCI rulebook, it also guards against athletes circumventing the rules by using an overlong saddle.
The measuring jig to be used by commissaires for the adjudication of this rule looks like the one proposed in the prior article, but adds a second wire. The "harp" proposed here might easily be constructed by welding together pieces of rectangular, U, or I-beam stock, with a single wire forming a parallelogram and attaching to itself with a turnbuckle used to make the wire taught. There are any number of ways to construct the harp, this is simply the first that came to mind.
The forum then commenced a discussion of rule 1.3.023 which, as we all know, discriminates against tall riders, by also applying an X/Y standard to those of every height, but allowing for morphological exceptions that, it appears, are unevenly enforced and, as with 1.3.013, are in most all cases proscribed for masters riders.
One ingenious solution was to build the measuring jig longer than is necessary so that it can serve to enforce both rules. In this case, the bike is flipped around after 1.3.013 is measured, and the harp's vertical member passes through the BB. The distal inclined wire serves to indicate the limit of the aerobar's frontal protrusion.
The measuring jig to be used by commissaires for the adjudication of this rule looks like the one proposed in the prior article, but adds a second wire. The "harp" proposed here might easily be constructed by welding together pieces of rectangular, U, or I-beam stock, with a single wire forming a parallelogram and attaching to itself with a turnbuckle used to make the wire taught. There are any number of ways to construct the harp, this is simply the first that came to mind.
The forum then commenced a discussion of rule 1.3.023 which, as we all know, discriminates against tall riders, by also applying an X/Y standard to those of every height, but allowing for morphological exceptions that, it appears, are unevenly enforced and, as with 1.3.013, are in most all cases proscribed for masters riders.
One ingenious solution was to build the measuring jig longer than is necessary so that it can serve to enforce both rules. In this case, the bike is flipped around after 1.3.013 is measured, and the harp's vertical member passes through the BB. The distal inclined wire serves to indicate the limit of the aerobar's frontal protrusion.
The idea is to incorporate scalability into the rule governing a rider's allowable distance from BB to bar tip. The proposed rule also allows for the use of the harp for to measure the bike for both rules.
The problems are two: it's not easy for a rider to determine his bike's legality without his having his own measuring jig; and it's just a guess as to whether 78 degrees, or 77, or 79, or whatever the UCI would choose as its maximum incline for seat angles, is also the appropriate angle for scaling up the max allowable bb-to-bar-tip as the rider's stature increases.
My simpler (and maybe simple-minded) idea is to make 1.3.023 a function of seat height. Coincidentally my saddle height (bb to top of saddle, halfway between the saddle's fore and aft) is the same distance as my cockpit length (saddle nose to bar tip). My morphology is average, and it is certainly foreseeable that riders with longer torsos and shorter legs might need a longer cockpit than I. So, would it be fair for 1.3.023 to be limited to saddle height + 5 centimeters? That would make the rule scalable, and easy to measure.
I have trade several emails with the UCI's technical chair. He's fain to entertain any consideration of rule changes during an Olympic year. While it seems to me fairness ought to be imposed before, and not after, the commencement of a significant competition, I am certainly sensitive to the constraints under which the UCI labors.
Accordingly, I have taken it upon myself to visit these issues now since, assuming the UCI's wisdom is greater than mine in these matters, the most appropriate time to change the rules is at the beginning of the next Olympic cycle. Since that will happen in about 10 months, best to start the discussion prior to that time: in other words, now.
The problems are two: it's not easy for a rider to determine his bike's legality without his having his own measuring jig; and it's just a guess as to whether 78 degrees, or 77, or 79, or whatever the UCI would choose as its maximum incline for seat angles, is also the appropriate angle for scaling up the max allowable bb-to-bar-tip as the rider's stature increases.
My simpler (and maybe simple-minded) idea is to make 1.3.023 a function of seat height. Coincidentally my saddle height (bb to top of saddle, halfway between the saddle's fore and aft) is the same distance as my cockpit length (saddle nose to bar tip). My morphology is average, and it is certainly foreseeable that riders with longer torsos and shorter legs might need a longer cockpit than I. So, would it be fair for 1.3.023 to be limited to saddle height + 5 centimeters? That would make the rule scalable, and easy to measure.
I have trade several emails with the UCI's technical chair. He's fain to entertain any consideration of rule changes during an Olympic year. While it seems to me fairness ought to be imposed before, and not after, the commencement of a significant competition, I am certainly sensitive to the constraints under which the UCI labors.
Accordingly, I have taken it upon myself to visit these issues now since, assuming the UCI's wisdom is greater than mine in these matters, the most appropriate time to change the rules is at the beginning of the next Olympic cycle. Since that will happen in about 10 months, best to start the discussion prior to that time: in other words, now.
Articles related to this one
X/Y Rules in an Angular World
In barely a month USA Cycling joins the UCI in legislating the Randy Newman ethic: "Don't want no short people round here." Fortunately, there is a deceptively easy alternative for both of cycling's governing bodies. 11.30.07
In barely a month USA Cycling joins the UCI in legislating the Randy Newman ethic: "Don't want no short people round here." Fortunately, there is a deceptively easy alternative for both of cycling's governing bodies. 11.30.07
Comments
In reply to Dan's Comment...
Reviewed by: greg steele, Dec 12 2007 10:00PM
FWIW, while the saddle 5cm rule might be "heightist", the 80cm rule is "lengthist" and favors the shorter rider. So not fair in one direction and the reverse in the other...
Just an observation
Just an observation
A few comments...
Reviewed by: Tom Anhalt, Dec 11 2007 7:15AM
Just a couple of thoughts:
* My proposal for the rewrite of 1.3.023 would most likely require another "2 wire" harp much like the one for the proposed 1.3.013 in order to account for varying BB heights. Lining up with the edge of the frame assumes a 24cm BB height.
* Alternatively, a "3 wire" harp could be used that places the 3rd string 66 cm horizontally away from the first string. That way, one would line up the 3rd string with the center of the BB instead of the vertical member after flipping it around to check the extension. If the 2 chosen angles are the same, then the wires would all be parallel. If the extension angle is different, the angle of the 3rd wire could be changed to give the correct spacing, still using the seat wires as the limit (no matter the angle chosen for the seat).
* The calculation and checking of the allowable extension would be pretty easy once an angle is chosen. For the example of an angle of 78 degrees and an offset of 66cm, the horizontal extension dimension as measured from the BB can be figured out from the difference in the heights of the seat and the BB off of the ground.
o Extension = 0.213 x (SH - BB) + 66cm, where SH is the vertical seat height measured off the ground, and BB is the vertical BB height measured off the ground.
Good luck in your "pushing" of this forward :-)
* My proposal for the rewrite of 1.3.023 would most likely require another "2 wire" harp much like the one for the proposed 1.3.013 in order to account for varying BB heights. Lining up with the edge of the frame assumes a 24cm BB height.
* Alternatively, a "3 wire" harp could be used that places the 3rd string 66 cm horizontally away from the first string. That way, one would line up the 3rd string with the center of the BB instead of the vertical member after flipping it around to check the extension. If the 2 chosen angles are the same, then the wires would all be parallel. If the extension angle is different, the angle of the 3rd wire could be changed to give the correct spacing, still using the seat wires as the limit (no matter the angle chosen for the seat).
* The calculation and checking of the allowable extension would be pretty easy once an angle is chosen. For the example of an angle of 78 degrees and an offset of 66cm, the horizontal extension dimension as measured from the BB can be figured out from the difference in the heights of the seat and the BB off of the ground.
o Extension = 0.213 x (SH - BB) + 66cm, where SH is the vertical seat height measured off the ground, and BB is the vertical BB height measured off the ground.
Good luck in your "pushing" of this forward :-)
Why?
Reviewed by: David Mclean, Dec 11 2007 5:13AM
The purpose of your new rule is clear, it is to make the original rule less 'heightist' (is that a word?). What isn't clear is why the original rule exists in the first place, it is entirely arbitrary. I believe it was invented on a whim by UCI Commissaires to prevent Graeme Obree from competing at pursuit competitions on the track and hour record attempts. Surely, instead of reworking this rule we should just scrap it altogether. After all, I understand Mr Obree hasn't changed height at all in the last 10-15 years!
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