Cycling is a sport about strategy and athletic power, not about technology. What a bike looks like is fixed so that the best rider wins instead of the best bike winning. You can build a more aerodynamic bike. You can build a lighter bike. The progress would be relentless and all money would be invested there if the rules allowed it. So they don't.

It's the same for many sports. You could use aluminum bats in major league baseball. They don't because they simply work too well. In addition to killing the pitcher if you hit a line drive at him, every hit would be a home run. They'd have to make the stadiums larger and add more outfielders. Why bother? Then they'd make the bats even more powerful, and the process would repeat again. So they just use wood bats.

There are plenty of opportunities to race streamlined recumbent bikes, by the way, it's just not the ruleset in play for the Tour de France. (And of course you can use a TT bike in the time trials.)

While that's true, I do wish there would be some "no technological limits" athletic events where they could go all out on technology just to see what the extreme would look like.

Historically there was Can-Am[0]: "As long as the car had two seats, bodywork enclosing the wheels, and met basic safety standards, it was allowed."

As others have mentioned, F1 is probably the closest today.

[0] https://en.wikipedia.org/wiki/Can-Am

I think formula 1 comes closest in that regard. There is some insane engineering that is done by top teams. I believe carbon fiber, ABS, disc brakes all came from f1.

A large part is also for looking for something that passes the letter of the rules, but not the spirit - a loophole.

The Mercedes F1 DAS system they intend to race this year when the season gets underway is just the latest example, but see also the 6 wheeled car, the fan car, getting around the ground effect ban, double diffuser, blown exhaust etc. etc.

It's one of the reasons I love the sport.

Maybe in the past, nowadays F1 have lots of technical regulations.

They do - but they also have scores of super smart engineers who each year manage to find a certain something - be it a loophole, or just something nobody else thought of.

See DAS this year, F Duct in the early 2010s, the 2009 Double Diffusers (when they were technically banned), Blown diffuser, CF layups that cause the front wing to flex under load etc. etc.

The regulations serve three main purposes which seem reasonable:

1) Increased safety

2) More entertaining racing (not much success here so far)

3) Reducing the cost so that it is economically sustainable even for smaller teams.

Still, the current cars are the fastest F1 cars ever.

That’s not a question of “progress” - it’s a question of safety.

Why tri bars should be unsafe? You have control of the steering, control of the brakes and your back is flat which increases comfort. Aerodynamically speaking your cross section is quite smaller.

Your control is greatly reduced in aerobars, but more importantly, your ability to defend your space is hugely reduced, which makes riding in a pack extremely dangerous. This video explains why having the ability to protect your bars prevents crashes: https://www.youtube.com/watch?v=sRIsWzrMmBs

Cycling has some dumb rules (e.g. sock length), but banning aerobars in mass start races is not among them.

This. Aero bars are nice for flats and descents. I wouldn't want to have to do a tough climb without drop bars or at least flat bars. And I definitely wouldn't want to ride in a pack with drop bars with my hands not on them. That sounds like a great way to wreck.

When you are on the the aero-bars your hands are not on the brakes and the your ability to perform accurate steering adjustments is greatly compromised.

There is a good answer to this question here:

https://bicycles.stackexchange.com/questions/10231/why-dont-...

Yes. Getting the upper body tucked narrowly is superior to basically everything here.

However, full-size tri/TT bars aren't even allowed in triathlons where drafting is permitted. Only recently have reduced-length aerobars been permitted in drafting-allowed races (aerobars no longer than the drop bars/hoods).

Full Tri/TT bars aren't allowed in UCI races because they poke out in front of the bars and hoods; there is some concern they could stab someone in a crash. UCI races allow drafting. The shorter aero bars are relatively new and there is certainly some resistance to change in UCI. I don't know how long it has been since UCI reduced the minimum weight limit but it's been 6.8 kg for quite some time.

Additionally, tri/tt bars reduce your steering stability, which is potentially very bad on a fast descent like this. Usually tri/TT bars do not have brakes on the extension arms — neither for clip-on aero bars for road bikes, nor dedicated tri/TT handlebars.

Anyway, I have aero bars myself and ride in that position going fast on flats and modest descents. But I go back to a wide, near-the-brakes position above 30 mph.

Tri bars are definitely the fastest that I’ve ever descended by quite a bit. Neither were in race conditions, once was on a mtb with road tires and aero like bars in upstate ny, and once on a tandem with aero bars on the US route that STP takes once crossing into Oregon.

Both times I hit 55mph, and the bike was rock solid riding at that speed on the aero bars.

The fastest descents I’ve done without tri bars has been in the 45 mph range, but I’m sure faster is possible with the right hills.