You could go even further and remove any ambiguity. For BTA you could say a volume defined by: A vertical line through the crankset spindle forward to the front of the handlebars, upwards from the lowest point of the aero handlebar extensions to (20cm, 30cm, 40cm, pick a number) above that same point, and outwards no more than 10cm from the midline of the bicycle on either side. Anything that fits in that box is good.
That should cover all of the “normal” BTA, you could just as easily do it for frame/BTS. If we can do this in 5 min on an internet forum then surely IM can figure something out. But that’s also kind of the point. They don’t want a hard and fast rule, they want a rule they can bend to disallow things they don’t like.
I think the key here, though, is to create a balance between “normal use case” and innovation.
If you just say that it has to be attached directly to the frame, then you allow some creativity/innovation on the part of frame designers but also that 99% of all athletes will just use the locations supplied by the frame designer. Plus, most locations on the frame are going to be aero negative anyway, so on a standard frame you’re just going to use the default locations. But if you’re specifying a location, then you may lock out tomorrow’s P5x/Andean/Cadex/Shiv reservoir, or whatever the future design might be.
If you start going down the path of specifying distance from a certain box, then you’re suddenly in UCI territory and today’s hydration location rule is going to become tomorrow’s 3:1, or round bottles only, or distance from stem to bar, or… (not that they’ll pick these rules, but the more specific the rule gets the more arbitrary future regimes will end up being)
Oh, I hadn’t seen that one. That’s a real shame. I don’t see the difference between putting that bottle holder between your arms and putting the profile designs ultimate aeria hydration between your bars. I guess they can make the argument that the bottle cage shouldn’t have the cone holder behind it, but in that case they should argue the PD hydration should have it’s pointed shape cut off as well.
I’d be curious if anyone has followed up with IM, because I’d actually like to buy that aero coach part and get it to fit on my bike. It looks clean and well made.
I suppose it’s getting to more a fundamental issue-do you want to see the best athletes in a fitness test or the best total package of man and machine? And the entire spectrum of possibilities in between.
As much as I can dislike the UCI, one knock on effect of their meticulous formulaic equipment ruling is that you can find UCI-legal road bikes that are competitive with the flagship models at not too insane prices. Yes, the top end is ungodly expensive, but aerodynamics within the UCI box has largely been solved and the difference between road aero bikes is minimal. Compare that to skinsuits where the technology is just emerging and there’s really no affordable option for the very best double layered suits.
Ya, but what you’re really saying is innovation stagnates around a certain point and then prices can come down. Whereas in other areas where there is actual innovation, the manufacturers are profiting from it. True, in some cases that innovation is snake oil, and in other cases it’s very marginal gains. But in other cases some meaningful advances can be made specifically because there wasn’t a box that every mfg had to stay inside.
This is a really great point. Nothing wrong with innovators profiting from their innovations, especially when those things are good for a society. I’m not sure I’d classify aerodynamic efficiency of bicycles as a matter of great societal importance (lol).
As fun as it is to loophole the rules and buy fancy new gear, constant innovation really does have a excluding effect on new athletes coming into the sport. I’m not saying tri’s should be locked to the extent of the Merckx hour record, but the free-for-all on gear is making it so a bike with the latest gear from ~5 years ago is a significant disadvantage. Frames/wheels/components are all the same, but custom/semicustom cockpits, high bottle storage, and a modern skinsuit are all minutes faster than the previous tech.
The barrier for all that isn’t at the entry level - it’s at the mid level.
Entry level triathletes arent thinking about how they can save 0.5s with a better ski suit or frame - they’re wondering if they can do it at all. This is even for first time Ironman people with some experience. Half the posts in the Ironman or Triathlon subReddits are “I signed up for this but didn’t train, race is next week” or “do I really need a TT bike or is my road bike fine”
It’s when you start getting competitive that suddenly the $10k frame or the $1k ski suit starts presenting a barrier
That’s a good point. Its easy (for me at least) to get so separated from the world that you forget others experiences.
It’s a tough situation in niche sports where the only fans of the sport are participants in the sport. So drawing in more participants is the goal. Which is a whole other can of worms.
I would argue the barrier is what people think they need vs what they actually need
We are fed so much false information that people believe they need that bike, with those wheels, with the $1000 suit and the nine bottles to make them stealth.
In the mean time they mess up getting their head in the right position and pumping their tires to the right pressure.
Just coming back to this thread now that his aero testing video is out.
The relevant takeaways (at least as this thread goes)
-Aero bottle was neutral for him
-He doesn’t say whether the current bottle setup is net benefit or not, but there’s a moment in the video where he says that they’re testing bottles specifically and that overall he found gains. Depending on when the video was shot relative to T100 I guess we’ll see if he keeps everything. If he does, there’s a decent clue here about the bottle setup
This video was before the switch to the Ekoi helmet too. A gain that he must’ve found during testing but didn’t include any non redbull branded helmet I imagine…
Looks well outside the current guidelines applying the rules to me. The lower bottle (looks like a 1l ref size) is way more than 250mm rear of the lowest point of the aerocoach arm rests.
I note the post to which you refer is from 2024: a lot of tides in and out of Carmarthen Bay since then. We are waiting for the 2026 IM Rules which I assume will be seeking to codify/clarify the hydration/fairing imbroglio.
Finally I thought that IM had clarified that the current (200mm x250mm box) rule was being enforced for pros (like @BenwGoodfellow ) not amateurs.
