Yes, **Cervelo’s **wind tunnel test showed the P4 beating the SC at low yaw angles…
Yes, and in Specialized’s wind tunnel data it showed the P4 beating the nosecone shiv at low yaw. In Trek’s white paper it is very very close at low yaw.
One thing missing is the integration of the hydration system vs. wind tunnel data with bottles and/or front bar mounted hydration systems. Maybe there will be an aftermarket for nose cones.
so, maybe UCI illegal shapes can make a bike much faster, but this new shiv is not evidence of that.
or maybe I am being too picky about what “much” is.
The thing I first noticed from the charts was the numbers. 26-41W for the Shivs! For the whole bike!!
There can’t be a lot of fat there to trim, so a lot of hard work, and a hard to make bike, saving you a pretty good percentage in drag… will still end up saving hardly any watts?
yeah to put it in perspective, I think Coggan said that an entire P3C with Zipp wheels, if it took you an hour to do a 40kTT on that
then if you had a 0 drag bike with 0 drag wheels, you would go 5 minute quicker
the latest round of superbikes are about a minute quicker than the P3C - so there are now only 4 minutes available =)
How many of those 4 minutes will the next generation be able to eat into?
Its a good question, if the Lotus design had been continually refined and developed instead of shelved in the late 90’s where would we be now? What if the Softride FasTT design had been given the same R and D as have gone into the double diamond designs? Both those bikes were faster than the P3 level.
If an aerodynamics group had a blank screen and no restrictions, what kind of design would they come up with. All the R and D has gone into UCI legal designs because thats where large companies with the development budgets have chosen to spend.
I am not saying that the non traditional designs are faster, but they just havent had the developement over the last 10 years of the UCI legal bikes.
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Both those bikes were faster than the P3 level.
You SURE?
If an aerodynamics group had a blank screen and no restrictions, what kind of design would they come up with.
Thats easy:
80 miles an hour
Of course if they could design a bike with negative yaw under, enough conditions, then its all open again. Still thats why I think for a Tri bike things like comfort, handling, fuel options, etc are important. Over a half or full those things can matter as much as those last 16 minutes or so.
For a TT 10 seconds can be a lot, as far as results go.
Styrrell
Yes, **Cervelo’s **wind tunnel test showed the P4 beating the SC at low yaw angles…
Y(s, and in Specialized’s wind tunnel data it showed the P4 beating the nosecone shiv at low yaw. In Trek’s white paper it is very very close at low yaw.
Umm… you’re glossing over the fact that competing tests showed significantly different results, Cervelo’s test showed P4 beating the SC at 0 & 5 degrees but losing at 7.5 and above. (Any depending on your POV, many would still consider 7.5 low yaw.) Trek’s test had the SC winning at all yaw angles, and it was only close at 0 yaw.
Stating that “P4 beats the SC” at low angles indicates you have chosen to believe Cervelo’s test, not Trek’s. Myself, I just view each test as additional data points, not one as the truth and the other not the truth.
I would suggest that there are no substantive differences in frame comfort or handling in any of the top TT bikes.
Someone with serious back issues might need a titanflex or something though.
Of course if they could design a bike with negative yaw under, enough conditions, then its all open again. Still thats why I think for a Tri bike things like comfort, handling, fuel options, etc are important. Over a half or full those things can matter as much as those last 16 minutes or so.
For a TT 10 seconds can be a lot, as far as results go.
Styrrell
The confluence of the Trek test, the Specialized test, and the Cervelo test and some other lines of evidence have led me to that conclusion, and by no means would I say I am certain about it. =)
Stating that “P4 beats the SC” at low angles indicates you have chosen to believe Cervelo’s test, not Trek’s. Myself, I just view each test as additional data points, not one as the truth and the other not the truth.
From the graphs of the 3 Shiv models though, you could draw the conclusion that any general reductions in drag from frame design will now be limited…
I wouldn’t draw ANY conclusion about the relative performances of the Shiv models until there are error bars displayed on those data points…
You can believe that, and I really don’t mind a difference of opinion. However, pose that question to any of the people on this forum that currently or in the past have been involved in the design or manufacture of bicycle frames. You will find that your opinion is in the minority. Which also doesn’t make it wrong, but you are going against the grain on it.
Styrrell
Both those bikes were faster than the P3 level.
You SURE?
I remember at the release of the P4 Gerard commenting they had finally beaten the Lotus in the drag stakes. When the Softride TT was released Softride had data showing less drag than the P3. You just havent been hanging around here long enough… 
oh no I remember well the softride claim.
I just do not believe the softride claim!
Both those bikes were faster than the P3 level.
You SURE?
I remember at the release of the P4 Gerard commenting they had finally beaten the Lotus in the drag stakes. When the Softride TT was released Softride had data showing less drag than the P3. You just havent been hanging around here long enough…
Ok
Damon Rinard,
Do you believe there are any substantive comfort or handling differences between the top tri bikes on the market right now? (specialized, trek, cervelo, specifically)
You can believe that, and I really don’t mind a difference of opinion. However, pose that question to any of the people on this forum that currently or in the past have been involved in the design or manufacture of bicycle frames. You will find that your opinion is in the minority. Which also doesn’t make it wrong, but you are going against the grain on it.
Styrrell
I will have to admit a bias towards Softride, I still miss my '95 PowerV 
I had all the Greg Welch look-alike gear.
Imagine how hilarious transition would be if we were all on fully faired recumbents…
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Both frames use the same manf process. Their is a very expensive re useable outer mold and then a non reuseable inner mold.
They aleady have a Shiv (UCI legal for TT), and a Shiv nosecone (UCI illegal for TT), Now they came out with a Shiv tri (Uci illegal).
People are asking for a third outer mold to be made Shiv TT non UCI legal. Thats a pretty tiny market and it pretty much would cannabilize sales from bikes they already sell.
Nope…the nosecone Shiv is no longer in production.
Here’s the thing…all they need to do is create a “nosecone-like” bayonet style fork that fits on the Shiv TT frame. Use the deep and narrow fork blades from the Shiv Tri. Mount the brake to the fork normally and cover it with a nosecone/stem support thing that might even have fluid or storage inside. That stem support design could even account for taller pad stacks if people desire that. After all, the main problem with the nosecone was that the structure wasn’t designed to be the simplest/best for the form…it was designed to skirt the UCI structure rules (i.e. brake attached to the nosecone instead of the fork, etc.)
There…now they have a bike that beats or exceeds the performance of the Shiv Tri and also meets 95% of their fit and fuel goals.
The bonus is that they have a bike that with a simple fork/stem swap is useable for ANY event, UCI or not.
Heck, they even could sell “UCI-illegal” modules (fork/stem) for already purchased Shiv TTs…or even have an option where you buy the bike with BOTH setups.
The bonus is that they then have just ONE style of frame mold to worry about.
That just seemed like it would be the more pragmatic approach overall…but, maybe that’s just me…
BTW, I was thinking the same thing as Jack
I have, and I think there is. Anyone got some calipers and a Speed Concept? We can measure this. If it DOESN’T have more frontal area, why is low yaw drag worse on the speed concept?
Is the Kamm shape better at yaw but worse at zero yaw?
All of the older Superbikes are so old by now that its hard to draw any conclusions. I’d love to see and update Softride or Lotus shape with some of the new aero desgn details.
With the better carbon, manufacturing and epoxy matrices, I’d really like to see a road going version of the one sided track Lotus, with a SC or similar front end. Basically losing 4 entire tubes off the bike has got to give you something good aerowise.
The other thing that has only been lightly touched on is hiding the drive train. QR has the downtube shift and Blue has the bent shainstay, but I think a builder named Wynn was the guy who basically built a massive chainstay that houed most of the chain and shielded most of the rear gears and RD. That was banned a long time ago, but i see to Tri rule against it.
Styrrell
good point, yes supposedly it is.
Is the Kamm shape better at yaw but worse at zero yaw?