"Why would you not retain the 120deg elbow angle limit to prevent superman?"

because you can famously, easily, game the test.

"I just grabbed a bunch of recent tri/tt fit data and created another sheet to test. Only a handful of those riders were UCI constrained. Most of the fails are the quite forward positions."

that's not my experience, or the typical experience, once a rider gets to 6' tall. even with the ME. this is a big problem for a lot of riders on a lot of teams. and, if you get that ME you don't get the other, which means saddles have to be 5cm behind the BB.

"TT attendance dropped massively here when they started enforcing UCI rules"

that's the thing. it does involve a LOT of riders. no way could i ride in any way comfortably if i had to ride according to UCI rules.

If that is your constraint, then go ahead and build a complicated jig. Again, do you think USAT rules allow for an unfair advantage?
I haven't seen the need for a jig at Kona or Hy-Vee.

You decided to use your divine powers to just edit my post instead of replying?

the test I referred to was the BB-arc test I proposed. You asked for maths - I did maths (in that sheet you, in your omnipotence, deleted the link to)
This is the calc I did for my position



And a snapshot of testing against client positions



A small allowance on top of the BB-Saddle Arc would let a lot more of those people into the acceptable envelope.

"You decided to use your divine powers to just edit my post instead of replying?"

sorry. that was a complete brain fart on my part. just too long a day in the chair. really, i've never done that, to my knowledge. jeez, i'm getting old. i just meant to reply to your post. sorry for deleting the link. let me look over the math and then i'll answer.

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Dan Empfield
aka Slowman

One thing that occurred to me.... how will people be able to semi-easily measure this at home?

That's why I'm proposing something that can be done with a piece of string. A lot of the ways of getting an equitable system lead down the road of really complicated measurements and a jig that few commissaires can operate.

At which point, again, the prudent thing would be to ask "Just what are we trying to accomplish here?"

If it's to maintain half-assed rules put in place basically to thwart a single individual and because some things were, at one time, an affront to someone's sensibilities, then perhaps it's time to take advantage of the new "regime" in place at the UCI try to get them to rethink the positioning rules altogether.

What are these rules intended to do and does that make sense? Step one.

Re-working rules just so that they are a "more equitable" version of something that doesn't make much sense in the first place is just putting lipstick on a pig IMHO.

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http://bikeblather.blogspot.com/

I totally agree.
If, as the UCI state, there are concerns about safety then the rules should focus on not having a dangerously forward weight distribution or limited visibility.
The wheel/brake lever rule makes sure riders can't go too low so is a safety/position rule that makes sense
Extensions no further forward than front of front wheel puts a limit on how forward you can go (bearing in mind that there are front centre limitations on frames).

But from what the Omnipotent one is saying it sounds like a radical revision is not really on the cards. You may need to shift your timescale a little more towards the geological to get in sync with the UCI.

You don't know if you don't try...

Plus, the new rules czar sounds a bit more technically savvy than the "philosopher" who was in charge of writing the current rule set...so maybe he'd be amenable??

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http://bikeblather.blogspot.com/

If we assume some kind of "looks right" requirement from the UCI, then you end up looking for a simple set of measurements that approximate the same kind of range of positions for everybody.
I'd suggest looking at it a bit differently - make a one time, complicated, series of measurements and use that to print a set of individual fit measurements on the rider's UCI licence.

i.e. One time gives you options - you could go with someone expert measuring riders bodies joint to joint and running that through a fit spreadsheet that can deal with different vector constraints. The output of that process gives you a line on your licence with A=xx B=xx C=xx, and those simple, bike only, linear, measurements are all the commisaires need to measure on the day to check compliance.

That would be ideal in some ways and would make sense for pros... but I think it is too much to ask for amateurs (where everyone must meet UCI regs). It requires another official who must be paid to make the measurements. Plus... based on what I've seen with UCI regs, any complication beyond kindergarten level will probably be lost on them.

I'm kinda liking the saddle nose at BB, and extensions (and hands) not past the front of the tire. Easy... no calculations needed... no jig either if you are on a level surface. Make an additional stipulation for 120 deg upper arm angle if you want, just so no one tries a superman. Sort of like the speed limit... make it 120 but don't DQ anyone unless they are clearly past 135.

And bring back the Mantis! Safety reasons my ass... guys kept doing it anyway by holding the bars with their pinkies...

Since you have a fairly large database of fit coordinates at hand, what is the range of the ratio of saddle height (your measurement A) over the distance from the saddle tip to the front of the pads (measure C - measure D + a typical pad length)?

If that's in a fairly tight range, that may be the answer...

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http://bikeblather.blogspot.com/

"Since you have a fairly large database of fit coordinates at hand, what is the range of the ratio of saddle height (your measurement A) over the distance from the saddle tip to the front of the pads"

we have an algorithm that predicts cockpit:

E = .72H - .67D

E = cockpit
H = overall rider height
D = saddle height

simply, the 2 numbers are close to equal, and vary just based on morphology (long leg = shorter cockpit than saddle height).

the problem is with split rail saddles. these sit back 4cm or 5cm versus standard saddles. so you have to take that equation and add about 4cm to cockpit.

if you just said, saddle height + 7cm, you would inconvenience almost no one. so, if you went back to the original thought, two parallel wires 15cm or 17cm apart, and then applied this saddle height + 7cm rule, you'd have my bastardization of your jig drawing, which i posted a bit further up.

but if you use that forward wire, this then gets you into the question of, to where? if the forward wire is angled forward, you are disadvantaged if you have greater drop. or if you use flat versus ski bend extensions. but i still have to calc it out to see if this is feasible.

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Dan Empfield
aka Slowman

OK...I'm confused. I thought measure E in your fit diagram was the saddle to pad "drop", no? I'm talking about the horizontal distance from the saddle to the front of the pads, not the drop.

In any case, here's my thought: You have the 2 wire harp. On the wire that is lined up with the BB, make a sliding attachment that has a tape measure, or incremented line anchored on it. Line up the bike BB with the "left" wire (as shown in the diagrams above) and move that sliding attachment to the saddle top. Holding it there, stretch the tape measure back to the BB center and add 7 cm (if that's the right number). Continue holding the anchor point on the wire and swing the tape measure upwards and the forward edge of the pads can't protrude forward of the arc swept by the +7cm location. The other extents of the pad (upper, lower, and rear) are defined by the handlebar "box" location shown in the UCI diagram above (top of saddle line, top of tire line, and steering axis respectively).

The other aspects of the bars (i.e. tilt, shape, etc.) are controlled by the current rules regarding 10cm vertical difference max between pad and extension end.

Control the pad locations, not the extension ends. Or, perhaps just the say that extensions can't go beyond the front edge of the wheel (simple to check).

What do you think?


Actually, the forward angled line was intended to define the max vertical line. In other words, take the intersection of the top of the saddle and the forward slanted line and drop a vertical line from there...a bit like the "corners" shown in that one suggestion above.

Anyway, I like the "arc sweep" definition of the forward box myself.

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http://bikeblather.blogspot.com/

"OK...I'm confused. I thought measure E in your fit diagram was the saddle to pad "drop", no? I'm talking about the horizontal distance from the saddle to the front of the pads, not the drop."

E in the equation was direct distance from nose of the saddle to the ends of the extensions, "ends" in this case being the shifter pivot bolt.

in general, whatever we recommend has to be:

1. not so far afield from what the UCI is now doing that there is no chance they'll consider it, that is, it has to fit into their world view;
2. jig must be relatively simple to build and use.
3. there should be a fairly simple way for somebody to know if their bike is conforming.

i'm for any reasonable way to get that done.

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Dan Empfield
aka Slowman

i think Tom's idea is fairly simple with the rotating tape. set limit forward for saddle at zero and rotation point of tape at saddle nose no matter where it is(as long as zero or further back) so saddle height plus 7 from nose of saddle and end of shifter end not ot be in front of that with leading edge of front tire max. or saddle nse could be your +16 78deg line with tom's rotating saddle height plus 7 tape, front of wheel max

dont think uci is going to go for forward of bb even for short women, maybe??

Is there a reason why the lettering in the equation doesn't match what's in your fit diagram?



Unfortunately, I'm pretty sure what you're asking for is one of those things like a "Good, Cheap, and Fast...pick two" :-/

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http://bikeblather.blogspot.com/

OK...I'm getting the impression that this is the one that you think the UCI would have a problem with in switching the control from the bar end to the front edge of the pads. But, this is why I asked about what your fit data above tells us about this.

This is how it should be presented to them. Hear me out:

A. Controlling to the end of the bar ends puts one more body measurement variable into the mix, i.e. forearm length. This is what causes the problems various riders have with their current fixed limits. We have a distance that not only should vary with body size, but also has another "tolerance" built into it, making the variation MUCH larger. However, what they really are trying to accomplish is controlling how far forward of the torso the upper arms are angled, no? No largely obtuse angles, no "Superman", correct? So, control the front edge of the arm rests...one can only put their arms so far forward on the arm rests before your elbows fall off the front, no? In short, this is an easier and more logical way to control what they are trying to control without unfairly hindering small or large riders since more of the body variation effects have been taken out of the measurement.

B. Put that limit for pad distance at a reasonable range that varies with height (i.e. roughly as a function of saddle height) so that a large segment of the riding population are reasonably accommodated. This is where you come in. YOU have the large database of fits that will tell us how that pad position typically scales with saddle height. That's why I asked for what your database could tell us about that. Plot saddle height vs. distance from saddle nose to front of arm pad and see how well a line fits to it. Add a "smidge" for a factor of safety. Just as allowable saddle position should vary with height, so should this allowable pad distance forward. If they still want an upper limit on the extension length, then simply add in the front edge of the tire requirement. Only the very largest riders would ever come close to that anyway if the saddle to pad distance is chosen properly.

Make sense?

Now then, I think your requests 2 and 3 are easily met by my current proposal. We just need to determine what the allowed "pad arc distance" is based on your data.

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http://bikeblather.blogspot.com/

I forgot to address this. In a situation where horizontal saddle position is artificially controlled, I don't think this is an issue. Guys who have to run by UCI rules and use a "nosed" saddle will be nose-riding anyway using the "pick a side" method. Their actually pelvis position will be in the same spot anyway (or very close) when they use a "noseless" saddle. There would be no need to add 4-5 cm (or 6-7cm as I've usually taken it).

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http://bikeblather.blogspot.com/

"Is there a reason why the lettering in the equation doesn't match what's in your fit diagram?"

i guess because i did not even remember this diagram when i came up with the letters used for the cockpit predictor. or maybe i just like the letter E. in any case, i say right below the equation what the letters stand for.

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Dan Empfield
aka Slowman

Yes, and that's partly why I was confused. The description didn't match your own chart. May I respectfully suggest that it might be a good idea to harmonize the letter callouts between your equation and your chart?

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http://bikeblather.blogspot.com/

I've got it!

My brain must've been working on this as I slept because I woke up with this idea popped into my head:

Is there a part of the bike that scales roughly with torso length? Can we just use THAT as a reference point? I think so. How about front-center? Here's my thought, do you know how rule 1.3.022 has a forward limit for the drop bars at the front wheel axle? THAT can also be used as the forward limit for the front edge of the pads! Then, put a limit for the extensions at no further forward than the front edge of the wheel.

The advantages of this is that naturally riders will choose a frame size that accommodates their torso size and it encourages riders to use frames with longer front-center dimensions (which is a good thing from a stability/handling, weight distribution standpoint), and someone won't be able to make a super-long front-center bike to try to game the system to allow super-man positions because of the overall wheelbase limit, and also the requisite bike geometry needed for a good handling bike (i.e. natural limits on steerer angle and fork offset).

Here's my overall suggestions (repeat of my suggestion for 1.3.013 from earlier in this thread):

1.3.013 - The peak of the saddle shall protrude no further forward than 17 centimeters in front of a line passing through the bottom bracket spindle and inclined rearward at an angle of 78 degrees from the horizontal.



Boom. That's it. No exceptions for track races, etc. Great...so, let's do the same for the front end.

Here's my proposal for section 1.3.023:

1.3.023: For road time trials and individual and team pursuit, 500m and kilometer time trials on the track, an extension may be added to the steering system; in this instance, the height difference between the elbow support points and the highest and lowest points of the handlebar extension (including gear levers) must be less than 10cm. Elbow and forearm rests are permitted and the forward edge must not be placed beyond a vertical line passing through the front wheel spindle (A), with the other limits set in article 1.3.022 (B,C,D) remaining unchanged. The extremity of the handlebar extension must not extend beyond a vertical line (E) passing through the front edge of the front tire. (See diagram <<Structure 1(B)>>)



There. That's it. IMO, the UCI diagram doesn't quite look right since the bike they've drawn there doesn't appear to be of proper scale for a TT bike anyway. But, take a look at various pics of TT positions on the net and you'll see that this looks reasonable. Also, if they think the pad position is too far forward, then it can be modified to be a certain distance (they pick) back from the front axle. Same with the extension limit.

There you go. Harp fixture for 1.3.013. The bike itself and a vertical member (one could use one edge of the harp fixture) for 1.3.023. If the forward limits for 1.3.023 are decided to be offset from the axle and front edge of the wheel, then vertical wires at the appropriate distance from one edge of the harp fixture can be placed on there as well. Line up the axle or wheel front edge with that edge of the harp and then make sure they don't protrude beyond the vertical wire.

Thoughts?

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http://bikeblather.blogspot.com/

The Danish federation has just written on its homepage that riders with a height of 190 cm or more can get an additional 5 cm of distance to the end of the shifters, i.e. 85 cm in front of the BB. This should come from UCI and be effective from April 29th, 2014, i.e. this Tuesday.

Anyone heard anything about this? It seems really sudden and strange.

17cm in front of a line drawn at 78 degrees means a short rider could ride a very steep position compared to a longer-legged guy since the 17cm doesn't scale. Why mix up angular and cartesian measurements in the same rule, and not stick to an angular measurement (say, Saddle Peak Behind 82deg Line) throughout?

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ZONE3 - We Last Longer

First time I heard about it, but it does seem to be legit.
http://www.knwu.nl/wp-content/uploads/2014/04/24.04.14_New-position-rule-for-very-tall-riders-FN.pdf