Some here have been claiming that it is easier to build a much faster bike if you don’t have to abide by UCI rules.
In the past, Gerard has posted here that Cervelo hasn’t bothered building a UCI illegal bike as they didn’t think they could reduce drag much by doing so anyway.
But, you WOULD say that if you don’t offer a UCI illegal bike, wouldn’t you?
So, now Specialized gave it a go, a new bike with a number of uci illegal features, designed by guys who definitely know their stuff, and the result?
A wee bit better at some yaw angles, a wee bit worse at others:
As another data point in this discussion I would love to see the yaw sweeps of the Illicito vs QR CD.01
Does removing material from a seat stay and adding it to a chain stay have a net benefit? It could, especially if the ‘Shift’ is really channeling air through that seat stay area.
Jack, you’re forgetting the most important part here, the person. The bike is only 35% of this equation, put a damn good position on the bike, then you have the best aero bike, no?
ah, no I’m not forgetting that, this just isn’t a thread about that =)
or are you suggesting that a UCI illegal position would allow a better position? thats true but all of these bikes let you get forward of the BB if you want
Jack, you’re forgetting the most important part here, the person. The bike is only 35% of this equation, put a damn good position on the bike, then you have the best aero bike, no?
I think you guys are missing a HUGE point of this design. Specialized managed to make a bike that is on a level playing field with it’s best TT bike to date, while simultaneously making a bike that incorporates more tri-friendly features and user-serviceability. We’re solo athletes, mostly with limited mech skills, who just want a fast bike for the sport we love. We’re not major cycling teams with all the attendant support that mitigates the user-unfriendly features inherent in all-out race designs.
What do I mean? What do I like?
You get easy-to-change vertical dropouts. I’ve used both. I’m equally quick with both. But given a choice…I prefer the vertical dropouts. The fact that Specialized did that with no apparent aero penalty relative to the other bike(s)…plus in my book.
Integrated hydration system. This is absolutely huge to me. For every other bike out there, except maybe the P4 numbers where the integrated bottle is aboard…you have to take the raw numbers and figure out how much worse you’re going to make them with whatever your preferred drink system is. And for me, I’ve always hated adding weight to my front end with bottles on the bars. Here you get an integrated system that is included in the basic drag numbers, and which will handle most of the hydration needs up 1/2 IM distance. For me, for IM, I’d add a regular bottle between the bars and call it a day. No longer does the AVERAGE triathlete have to make the dubious aerodynamic decisions between down tube, seat tube, or behind the saddle. Huge, in my book.
No hard-to-service front brake setup. Simple, straight forward design that doesn’t require special tools or knowledge to deal with. That’s important to the general triathlon population, who don’t want to have to futz with some odd design or have to take the bike to the shop for every little issue. And even more importantly…the design is serviceable on the road in training or even in a race with normal tools we tend to carry, and without complete disassembly of areas of the bike to get at the parts.
Some of you will be unhappy that they didn’t just completely maximize aero and you’re going to analyze and pick apart the design looking through that very narrow lens.
I think it’s a significant achievement on Specialized’s part. Give me an add-on aero box similar to Trek SC’s and better Di2 battery integration and I’d have absolutely nothing to quibble about.
ah, no I’m not forgetting that, this just isn’t a thread about that =)
or are you suggesting that a UCI illegal position would allow a better position? thats true but all of these bikes let you get forward of the BB if you want
Jack, you’re forgetting the most important part here, the person. The bike is only 35% of this equation, put a damn good position on the bike, then you have the best aero bike, no?
Exactly. I ride that way now, oops. If you’re going to make a illegal UCI bike, go ahead and pump it out the door with a UCI illegal position platform.
One thought that occured to me. If we use the P4 as an example its faster with the integrated bottle in place than with no bottle or aero bottle right? But the bottle makes the BB area non UCI compliant and cant be used. So in this case being UCI illegal is faster… slightly! Personally the position restrictions such as 5cm behind the BB for all sizes, level saddles?!? I find more annoying philosophically than the tubing ratio restrictions.
Why? Ignore the fork which both bike designs would have. With the pictured bike air would hit one frame member and go past. With the seattube, air would hit the headtube then hit the seat tube again.
CdA isn’t as easy as all that, which is why even with CFD they do mock ups in a WT (and road testing after that), but I have seen any compelling data that makes it abvious erasing the ST is better than erasing the DT or vice versa.
I don’t know why, I just know that when the USA was designing super bikes in both configurations the seat tube one tested faster than the downtube one
probably because the seat tube shields the rear wheel, but that is just a guess.
now the guy in charge of the project was told the seat tube one was faster, and opted to go with the downtube design anyway.
don’t know why
Why? Ignore the fork which both bike designs would have. With the pictured bike air would hit one frame member and go past. With the seattube, air would hit the headtube then hit the seat tube again.
CdA isn’t as easy as all that, which is why even with CFD they do mock ups in a WT (and road testing after that), but I have seen any compelling data that makes it abvious erasing the ST is better than erasing the DT or vice versa.
Even handling? As long as you can get your feet, butt, hands and elbows in your preferred position you don’t think it effects handling much, no matter which frame you achieve this position on?
I don’t know why, I just know that when the USA was designing super bikes in both configurations the seat tube one tested faster than the downtube one
probably because the seat tube shields the rear wheel, but that is just a guess.
now the guy in charge of the project was told the seat tube one was faster, and opted to go with the downtube design anyway.
don’t know why
Why? Ignore the fork which both bike designs would have. With the pictured bike air would hit one frame member and go past. With the seattube, air would hit the headtube then hit the seat tube again.
CdA isn’t as easy as all that, which is why even with CFD they do mock ups in a WT (and road testing after that), but I have seen any compelling data that makes it abvious erasing the ST is better than erasing the DT or vice versa.
Styrrell
Now, if it were just biking in the olympics, then it would be obvious to do whatever is faster for just biking; but I am getting to be an old fart and I love my titanflex. It takes the beating out of the ride. I cant say that I am faster off the bike than a double diamond, but that is only because I dont have enough time to do any decent amount of training to answer that question.
Remember I was restricting the question to the current top TT bikes.
I’m sure there exist bikes that handle pretty bad.
Even handling? As long as you can get your feet, butt, hands and elbows in your preferred position you don’t think it effects handling much, no matter which frame you achieve this position on?
