"okay saddle nose to c of b-b plumb line is -5cm"

with that saddle setback you'd have to be a severe nose rider and/or very long torso, short legged, in order to need more than your seat height in extension reach.

still, if the saddle rule was changed allowing for more forward movement, then the 1.3.023 rule would have to be altered accordingly.

perhaps the typical guy requires a cockpit distance equal to his seat height, but the squatty folks require an addl 5cm. in this case, the max would be seat height + 5cm.

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Dan Empfield
aka Slowman

OK...here's my proposal for "The Unified Theory of Measuring Saddles and Aerobars" (TM) ;-)

Here's my rationale/reasoning:

• The allowable saddle angle is chosen to allow for differences in the size of people and is represented by a line declined from vertical and offset forward from the BB axis by 17cm. The tip of the saddle may not be in front of this line.
  
• The same angle should also be used at the front of the bike to vary the allowable extension (e.g. 78 degree seat angle, 78 degree bar tip angle...Envision an inverted triangle overlayed on the bike)
  
• The "anchor point" for the bar extension measurement is a point that is 75cm in front of the BB, at a vertical height of 67cm. This represents the top of a 700x23c tire. This "anchor point" was chosen merely to coincide with the lower limit of the current UCI rule)
  

Now, here's the cool thing. With a minor change to the "harp" device, both the seat position AND the bar position can be checked with the same jig. See below:



Basically, you need to place the right hand vertical member of the harp frame at a distance of 75cm - (67cm/tan(angle)) from the lower anchor point of the left wire. In the example above with a chosen 78 degree angle, this distance is 60.8 cm. (With the program I've drawn the above schematic, I can vary the chosen angle and the offset will be automatically calculated and the drawing modified).

To use the rig, you first check the seat position as previously discussed in this thread. THEN, you flip the bike around so that the bars are pointed to the left and line up the center of the BB with the right vertical harp frame member. The tips of the bars cannot extend past the left-most wire (along with not being above the top of the seat, not below the top of the tire, or behind a line through the center of the head tube...as in the current UCI rule). That's it.

I'd post some pics with a bike overlayed, but I don't have that capability right now...maybe later.

What do y'all think??

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http://bikeblather.blogspot.com/

squatty? As a kid I was called husky (and much worse!) so I guess that would fit. Pure inseam is about 87cm.
Long arms so I'd make an excellent orangutan :-)

Re the saddle, I consistently ride 10+cm forward when going 'hard' on the flats. Effective STA would be fairly steep I guess.

sounds interesting. Is your dwg to scale?

Yes. Are you going to plop it on some bike pics for me?

Tom "Sawyer" Anhalt

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http://bikeblather.blogspot.com/

I have not yet developed opposable thumbs so .....

"OK...here's my proposal for "The Unified Theory of Measuring Saddles and Aerobars""

am i right in assuming that this jig measures both the NEW saddle position rule as we've been discussing, and also measures the EXISTING bar tip rule as expressed in 1.3.023?

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Dan Empfield
aka Slowman

Well...sort of. The existing bar tip rule has a hard vertical limit at 75cm forward of the BB, with the possibility of an extra 5cm with a morphological exception. My proposed modification to that rule, as measured by the proposed jig, keeps the 75cm forward of the BB dimension at the lower forward corner of the bar "box" (i.e. the area defined in 1.3.023), but then slants the limit line forward at the same angle used for the seat angle measurement. The further "up" the bars are, the further forward they can go, up to the limit of them being no higher than the top of the seat.

With my current example angle of 78 degrees, for the previously mentioned hypothetical person with a saddle height (BB to saddle distance) of 90cm, the allowable reach extends an additional 9.4cm in front of the BB (when the bars are at their highest allowable).

I'll play more with this later this evening and put up some better pics demonstrating the concept.

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http://bikeblather.blogspot.com/

i completely fail to understand your fixture. the failing is mine, not yours. perhaps you can just give me some idea of the proposed rule text for 1.3.023, and then i'll better understand (i hope) the fixture.

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Dan Empfield
aka Slowman

I hope this pic helps, I overlayed it on a pic of a setup that I knew was somewhat close to the current bar limits:

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http://bikeblather.blogspot.com/

I've been at USACycling events where the race officials have opted to force riders to use their backup (i.e. conventional) wheels over 3/4 spoke designs, stating that because there were U23 points to be earned for qualifying riders the technical rules would apply. Never affected me, and I for one appreciate NOT having someone on a flimsy 4 spoke (Rev X) in the same paceline as me.

Dan,
Could you possibly include the amendment of the UCI rules (final version between you and Damon) in your essay on the front page ? Or PM me the final version so that I can add attach it to your explanation/argumentation.
Thanks,
Laurent

I have just skimmed through this thread, may have missed something. I have a couple of questions:

What is the origin of these rules and why were they put in place in the first place?

Was it to prevent people from riding recumbents or something? Why are the rules different for the track?

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http://mclean.errl.org.uk

doesn't your proposed 1.3.023 rule penalize the guy who wants to ride with a lower front end and/or a flatter aerobar versus an upturned aerobar? i think what you're advocating is a system that ties bar-end limits to aerobar height and aerobar tilt. but if i'm a tall guy and i ride with the aerobar height of a shorter guy, i think i'm getting hosed.

let us take two guys, one has 75cm of saddle height and rides with 13cm of drop, and a guy with 80cm of height and 18cm of drop. assuming they each ride with the same aerobar tilt, they effectively have the same bb-to-bar-tip limit, no? maybe the rule you're proposing is okay. i, the obtuse one, need more hand-holding.

my idea for 1.3.023 is: saddle height (bb to saddle top) + 5cm. that's what you get, that's your limit.

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Dan Empfield
aka Slowman

It was a response to Obree's 'egg' position, which he rode crazy steep.

Why the different rules for kilo etc? Probably because Obree didn't ride those events (seriously). If he had, it would probably be in effect there as well.

Yes...I see what you're saying. My thought process was that if you overlay a rider on the bike (for a particular position) and gradually "scale up" their size, the seat and bar end positions will be defined by a "V" shape...so let's define the limits using that shape. I'm also trying to come up with a way to use the jig so that no measuring is required. With your proposal for 1.3.023, the commissaires will still need to measure the saddle height and then add 5cm to it, and then measure the horizontal distance to the bar tips. I think we can come up with something "cleaner".

However, as you point out, my idea doesn't take into account the variations in bar height/hand angle that can be employed. Another problem is that it would tend to encourage a more "Superman"-ish TT position, which obviously isn't something the UCI would go for since that's basically part of the reason the rule exists in the first place.

Hmmm...I think I may have just thought of a slick way of modifying the "harp" jig so that your "saddle height" + 5cm proposal could be quickly checked with no measuring :-) I'll post something when I get a chance.

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http://bikeblather.blogspot.com/

In which case, why isn't the rule scrapped rather than altered? The rule was made up on a whim to spite someone for being creative and thinking out of the box, wasn't it? The rule should be broken and flaunted in opposition to the UCI.

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http://mclean.errl.org.uk

"I think I may have just thought of a slick way of modifying the "harp" jig so that your "saddle height" + 5cm proposal"

i await with eager anticipation.

that said, let's apply to this discussion the test of reasonableness. i don't know, but i'm willing to guess, that a commissaire who engages in this sort of testing with any frequency at all would pretty quickly get to the point where an illegal 1.3.023 looks curious to the eye. then he takes out his tape measure and within 15 seconds determines the bike's legal status. i don't know that 1.3.023 requires the measuring of every bike.

furthermore, i think it a wise policy to remind riders that your bike is not necessarily legal because you're allowed to toe the starting line. your result is still subject to protest by another rider after the race, assuming such protest is lodged in the prescribed time and manner. cockpit distance is not an easy one to "retrofit" just after the finish, as would be the saddle nose. the failure to present your bike for inspection after the race, upon the lodging of a protest, would be grounds for disqualification. plus, assuming the rule is sound, the need to cheat would not be there.

i think the tool to measure 1.3.013 takes care of the lion's share of potential infractions, and while 1.3.023 needs to be updated, i don't know that it's a deal breaker of the tool doesn't measure it.

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Dan Empfield
aka Slowman

have you ever ridden a UCI event or event following UCI rules? Commissaires don't enjoy the word "flaunt" ....

I've ridden plenty... and yes, you are right, some of them don't enjoy the word "flaunt". I just have this great image in my head of 50 masters sawing off the ends of their saddles in front of some UCI Commissaires a la flying scotsman in mass protest!

Its still a bit silly to 'update' the rule when it really shouldn't be there in the first place. its a nice little thought experiment updating it and I can see everyone has had fun inventing designs for jigs and new rules and things but no one has given a decent explanation for why there should be a rule like this at all.

I'd like to hear one. Then I'll join in with all the jig fun.

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http://mclean.errl.org.uk

as posted yesterday

http://forum.slowtwitch.com/...post=1588226#1588226

i honestly don't know either. Time to get Graham O'bree on here to give us the real story behind it all.

Wouldn't that be cool?

I doubt the guy has a clue why the rule exists himself, except that it was made up to piss him off. We all know they were just discriminating against him because he was being different. Why 5cm and not an angle? you'll have to ask the UCI officials the day they plucked the rule from their arse.

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http://mclean.errl.org.uk

it's not just the 5cm part. The 75cm limits taller riders ...

But darned if i know exactly why those limits. I envision some monster HAL-style supercomputer in the UCI basement. Or maybe the Wizard of Oz is more appropriate :-)

OK...I failed in my current attempts at incorporating your proposed "seat height +5cm" extension into the jig...I'll let my subconscious work on that a bit.

However, in looking back at my pic above, rather than using just the wire as the "hard limit" forward, how about if the intersection of a horizontal line at the seat height with the wire defined the overall limit in the horizontal direction? In other words, if the top of your seat is at 67cm, then the extension is 75cm. For every cm the seat is above that vertically, you get an extra amount equal to the 1/tan of the angle. That means that if the seat was level with the top of the jig, the allowable extension would be 75cm+ 9 cm all the way down to the top of the tire. Sound promising?

Here...the blue line represent the vertical height of the seat. The intersection with the left wire defines the orange vertical line that is the allowable forward limit for that seat height.



Obviously, the absolute values of the "anchor point" dimensions as well as the angles are open for discussion.

Perhaps a sliding horizontal cross bar could be added to the rig to better define that intersection?

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http://bikeblather.blogspot.com/

i like that a lot better. i have three practical concerns:

1. if you're just john q racer, and you don't have a fixture, you just want to be able to set your bike up legally, then this is a tough one, except if you make sure everyone has a graph at their disposal (we can't require them to do trig). it lacks ease of use.

2. same as #1, but for commissaires who do not have the tool at their disposal. of course, they really can't easily do 1.3.023 without the tool at the ready either.

3. is the tool getting prohibitively expensive to build?

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Dan Empfield
aka Slowman