UCI abolishing 3/1 rule thread

Discuss light weight issues concerning road bikes & parts.
ultyguy
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by ultyguy

Got caught up in the 'PRO' thread but I'd love to hear any more info that people have heard regarding this. I'm in the market to buy a TT frame for next season's UCI GF series. Are they going to adopt the 'tri' regulations?

snaaijer
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by snaaijer

I doubt it will be tri rules because that basically means you're good to go as long as you have a helmet and functioning brakes (in non-draft)... There are other limiting UCI rules such as saddle position and extension length etc etc that seem to still be upheld.

Here's a recent article by Cycling Weekly on the matter: http://www.cyclingweekly.co.uk/news/lat ... ign-281563

Addendum:

Apparently the rule change will only affect frames and not components so things like aerobars and seatposts will still have to conform I think.

Some interesting commments from an engineer at Canyon about what the change might bring (keeping in mind he has a vested interest one way or the other, obviously):

http://www.cyclingweekly.co.uk/news/pro ... ign-281626

by Weenie


CarlosFerreiro
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by CarlosFerreiro

It looks like this is a minor change, only getting rid of the 3:1 limit and still keeping the 80mmx25mm maximums and all the other frame envelope limits.
So the few areas of the frame that 3:1 limited to 75mmx25mm would now be able to go to 80mmx25mm.
At least if they had applied it to seatposts too then a few older frame would have become legal again - old Cervelo P2 and P3 models for example. :cry:
Last edited by CarlosFerreiro on Mon Sep 05, 2016 4:37 pm, edited 1 time in total.

Nefarious86
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by Nefarious86

^^ Seems ridiculous that they have relaxed part of the rules yet still excluded some pretty neat frames.
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Kurets
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by Kurets

I don't see why this would make any difference other than making the bikes uglier. Of course it will make a good argument for "last years aero bikes suck" but thats just marketing.

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Stalkan
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by Stalkan

All things being equal narrower is more aero, correct? So, if they can make the tubes narrower while keeping the depth the same it should make for faster tube shapes.

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Calnago
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by Calnago

Stalkan wrote:All things being equal narrower is more aero, correct?

A few things to consider.... 1) moving objects experiencing winds at any other angle than head on (zero yaw) can benefit aerodynamically from "shapes" on the sides, so just saying "the narrower the better" is not true in most cases and 2) handling in cross winds is severely affected as you expose more surface area to them, so simply increasing the "3" part in the ratio negatively affects handling. And 3) handling in cross winds can be made more stable simply by making things stronger in that direction (I.e., increasing width and in effect making things less "noodly", or adding more or stronger material at the expense of light weight).
Basically, nothing is free and it's always a challenge to get that perfect combo of everything that works in all conditions. I really don't think the rule change is going to make things all that different performance wise than they are today, but it will give the marketers a little more leeway in their "spin" on things. They must be getting somewhat bored.

CarlosFerreiro
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by CarlosFerreiro

Sorry, bad wording in my post above, the 25mm permitted on the main tubes is a minimum and doesn't seem to be changing at the moment, so there doesn't seem to be a chance coming to make the tubes narrower.

Before the longest cross section you could do was 80mm x 26.67mm <-> 75mm x 25mm, limited by 80mm max, 25mm minimum and 3:1 max ratio.
Now it looks like you will be able to have up to 80mm x 25mm, limited just by the 80mm max, 25mm minimum box that seems to be staying in place, and the old 3:1 ratio limit goes away.

The parts of the frame that were limited purely by the 3:1 ratio before were fairly limited too - the middle sections of the main tubes basically.
Headtubes, BBs, gussets, dropout allowances etc took that limit away from a lot of the rest of the frame.
Still waiting to see all the new words though ;)

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Samuel Sanchez Gonzalez
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by Samuel Sanchez Gonzalez

Kurets wrote:I don't see why this would make any difference other than making the bikes uglier. Of course it will make a good argument for "last years aero bikes suck" but thats just marketing.

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Spot-on :beerchug: :thumbup:

Stalkan
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by Stalkan

CarlosFerreiro wrote:Sorry, bad wording in my post above, the 25mm permitted on the main tubes is a minimum and doesn't seem to be changing at the moment, so there doesn't seem to be a chance coming to make the tubes narrower.

Before the longest cross section you could do was 80mm x 26.67mm <-> 75mm x 25mm, limited by 80mm max, 25mm minimum and 3:1 max ratio.
Now it looks like you will be able to have up to 80mm x 25mm, limited just by the 80mm max, 25mm minimum box that seems to be staying in place, and the old 3:1 ratio limit goes away.

The parts of the frame that were limited purely by the 3:1 ratio before were fairly limited too - the middle sections of the main tubes basically.
Headtubes, BBs, gussets, dropout allowances etc took that limit away from a lot of the rest of the frame.
Still waiting to see all the new words though ;)


Ah, explained that way, you're right it doesn't seem like much is changing or will be. Really the ratio rule could go with zero change to the effectiveness of the rule due to it being somewhat redundant.

Stalkan
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by Stalkan

Calnago wrote:A few things to consider.... 1) moving objects experiencing winds at any other angle than head on (zero yaw) can benefit aerodynamically from "shapes" on the sides, so just saying "the narrower the better" is not true in most cases


I did say all things being equal, that is the narrower shape still gets a "shape". Also, isn't most testing today showing that most fast guys are <5º wind angle than the previous conceived notion that yaws of >10º were common?

Calnago wrote:2) handling in cross winds is severely affected as you expose more surface area to them, so simply increasing the "3" part in the ratio negatively affects handling.


Shaping has to help here, as I don't find this to be the case at all between my AR and 7 (aero frame vs round tube); however, I agree that a broad flat shape would effect handling aversely.

Calnago wrote:Basically, nothing is free and it's always a challenge to get that perfect combo of everything that works in all conditions. I really don't think the rule change is going to make things all that different performance wise than they are today, but it will give the marketers a little more leeway in their "spin" on things. They must be getting somewhat bored.


Agree 100%

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jerk
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by jerk

i have seen nothing from the uci indicating that they are going to implement this change. all of this banter is simply based on some quotes from one person who may or may not have any insight. the uci has always consulted with folks in the industry- but none of this stuff seems to be based on any thing other than some banter.
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cyclenutnz
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by cyclenutnz

I was at the eurobike WFSGI meeting, the rule change was based on consultation with the industry. The uci rep explicitly stated that 3 to 1 is gone on Jan 1st.

I don't think it's a good rule change, it doesn't accomplish anything. Main sections of tubes are not creating much drag now and many bikes have wide DT to shield bottles for best realistic performance and that's not going to change.

It just allows manufacturers to claim that your bike that was limited by the old rules is now too slow to bother showing up to race. The speculation in the cw article is just flights of fancy.
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ultyguy
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by ultyguy

Dragging this one back up. Orbea has managed to put some forks on that defy the old 3/1 rule. http://www.cyclingweekly.com/news/produ ... del-339260

My question is then specifically around the Giant Trinity Advanced Pro models. Only the frameset comes w/ a UCI compliant fork but these were designed before the laxing of the 3/1. The other models have a Tri specific fork w/ I guess a greater than 3/1 ratio. Would these now be legal?

CarlosFerreiro
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by CarlosFerreiro

The envelope for (the main parts of) the forks has gone to 80mm x10mm, so plenty of gains there compared with the old 3:1 limit.
I have seen articles where it has been said that, for example, the "non-UCI" for for the Trek Speed Concept was now being allowed by the UCI under those changes.
The slight issue is that the UCI approved list of frames/forks haven't been updated to include forks that are legal under the new limits.

Technically just complying with the new regs is not enough, the forks still needs to be formally approved. In practice the UCI don't seem to be going that way ;)
It does leave everybody unsure about which forks meet the new limits though.
Worth a look at the figure on page 21 here, to see just how little of the fork is limited only by the 80mm x 10mm box - http://www.uci.ch/mm/Document/News/Rule ... nglish.pdf

by Weenie


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