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CaptainRaiden
11th March 2007, 06:12
Now i had some questions circling around in my head for some days.

First off, can motogp teams change their aerodynamics within the season or are they stuck with the same package they started with? For example the Ducati aerodynamic package seems a little 'Bulkier' compared to the Yamaha or the Honda. While it may have the same length for the wheelbase, it still looks a little bigger. But as of now it seems it suits the ducati just fine, and boy does it go like a bazooka! But still, are they allowed to shed some fat as the season progresses?

Secondly, that monsterous Desmodronic engine in the Ducati. I feel Ducati might have to cut some major revs for slower circuits as they might not be able to carry more corner speed, so in theory it might get difficult for them to manouevre that bike very well in the corners. One of the major reasons why Rossi's yamaha is so nimble and agile in corners is firstly because of the way the bike is setup and secondly, maybe even because of the lower revving engine which allows rossi to carry more corner speed and avoid sliding.

Also, the Desmodronic system/technology Ducati use for their engines has been known to be a "little" inferior to the Pneumatic system used by other teams. However both of them have their own advantages and disadvantages. Ducati worked and tested on their engine like maniacs and have managed something really special, no doubt. But can that monsterous, but also a bit fragile engine be consistent and deliver them a championship?

Your thoughts?

maxu05
11th March 2007, 13:52
Firstly, the Ducati probably has the most efficient aero package out there. That is part of the reason it is so quick down the straight. As for the Desmo valve action being inferior, I don't think so, just look at the WSBK victories that Ducati has won. I wouldn't say it is a better system than the more conventional valve systems, but Ducati makes it work rather nicely thank you :)

Kropotkin
12th March 2007, 10:04
First off, can motogp teams change their aerodynamics within the season or are they stuck with the same package they started with? For example the Ducati aerodynamic package seems a little 'Bulkier' compared to the Yamaha or the Honda. While it may have the same length for the wheelbase, it still looks a little bigger. But as of now it seems it suits the ducati just fine, and boy does it go like a bazooka! But still, are they allowed to shed some fat as the season progresses?


There are no rules or limitations on aerodynamics, other than that so-called "dustbin" fairings are banned:
http://www.motorcycle.com/mo/mcracing/mcphotos/gphistory08t.jpg

Teams can, and do, change the aerodynamics from race to race. And the Ducati does not just look longer, it is longer, as the front bank of the L four (what Ducati calls their 90 degree V) is close to horizontal. That makes for a long engine. This makes the Ducati quite a handful at much tighter tracks, as was demonstrated down the rear section of the Qatar track, where Rossi could easily chase down Stoner round the back, but lost him on the straight.

As for the desmodromic system, Ducati are stuck with it, as it's their USP, their franchise is based on it. For the moment, it will do just fine, as the bike is revving to close on 20,000 RPM already. But if Ducati have to up the revs in search of yet more power, they may start to have a few more problems.

leopard
12th March 2007, 10:18
'Dustbin' is more suggested for placing ash of cigarette :s mokin:

No bike can visibly beat Yamaha designing aerodynamic package, not sure for its affectivity, agree with you Ducati just looks the bulkiest, but i don't mind if it can deliver final result like Lossail.

btw, welcome to forum :wave:

Kropotkin
12th March 2007, 10:26
'Dustbin' is more suggested for placing ash of cigarette :s mokin:



Actually, they were called "dustbin", because dustbin is the British word for trash can or garbage can, something like this:

http://data1.blog.de/blog/h/horse1/img/dustbin.jpg

Only with a big booming six cylinder inside it :)

leopard
12th March 2007, 10:33
in my office's smoking area there are two look-alike that picture named 'dustbin', but it has two orifice, on top for placing the ash and on the side for putting the stub, you may use it for different purpose :)

tha_jackal
12th March 2007, 12:15
Welcome to the forum Kropotkin, great to have someone of your expertise and knowledge participating in the forums discussions.. :) :up:

Kropotkin
12th March 2007, 12:19
Thanks, jackal! You can't get away from me anywhere, can you ;)

leopard
13th March 2007, 03:40
oh..seems you have known well each other, this world isn't wide as it looks

welcome again Kropotkin, I'll take a look at your site

axxexs
13th March 2007, 08:41
Hayden did get a new fairing to the Losail race. Dont know if Checa also get it. It's was a little wider front on that.

The Ducati looks a lot lika a Cagiva from 1992. :)

The aerodynamics is also a compromise. If you do a fairing that is good for topspeed that fairing will do the bike to be hard to change directions in the fast chikanes/curves for an example.

leopard
13th March 2007, 09:19
compromise or contrariwise, a good top speed fairing isn't good in the chicane?

Kropotkin
13th March 2007, 10:51
For top speed you want a slippery fairing, which means a fairing that is as long as possible, covering as much of the side of the bike as possible, with no lumps or bumps to disrupt airflow. The problem with a long fairing in chicanes is simply demonstrated: Pick up a big oval plate, or long piece of cardboard. Stand the bottom edge on a table, and try to rock the plate or cardboard from side to side, as if it was flicking through a chicane. That big long fairing now has lots of resistance to the air, and wants to stop you from pushing from side to side.

I hope that's clear, but I'm not sure whether I explained it well enough...

ArmchairBikeFan
13th March 2007, 21:41
I doubt that's a major issue for the Dukes, though. The bike isn't enormously long.
Aerodynamic drag equations are pretty weird, lots of cubed functions. Nothing much happens at low speed, then suddenly the effects kick in at a few tens of miles per hour. Effectively, it won't make any difference unless the sideways speed is pretty quick, which you'll never manage on a bike by tipping it into a corner. It's likely to be hugely outweighed by gyroscopic effects in chicanes.
More of an issue would be if you backed the bike in like Hayden, there would be a lot of area side-on to the airflow like a sail. A 250 riding style, with the wheels in line, wouldn't be quite as vulnerable to that.
Ducati have done an incredible job on this bike, the other teams must be in shock.

The Phantom
14th March 2007, 00:42
There's a lot of talk about how Rossi was able to make up time in the back part of the circuit (and watching the race, it seems true enough), but on the last lap Stoner decided to use what he'd kept in reserve for the whole race and he dropped Rossi like a stone. Personally I think the handling of the Duc is not nearly the liability that it's being made out to be.

Perhaps the focus should be more on the possibility that Stoner has learned how to ride a tactical race? Either way, the other teams should be worried about the performance of the Ducati.

Regarding aerodynamics, there seems to be two schools of thought at play - Ducati using a fairly bulky fairing with a long tail, and Honda going for the small short-tailed style. The money so far has to be on Ducati having it right. Capirex and Pedrosa are of similar stature and Loris was consistently faster in FP and qualifying (talking top speed here) - in fact all of the Ducs including the customer bikes were faster than anyone else!

ArmchairBikeFan
14th March 2007, 21:42
I'm with you on that, Phantom. On the last lap, Stoner was staggeringly quick around the whole track. It was fastest lap, and he didn't do that just by going fast on the straight. He was quick on the twisty bits. The next few races will be fascinating.

Kropotkin
14th March 2007, 21:52
There's a lot of talk about how Rossi was able to make up time in the back part of the circuit (and watching the race, it seems true enough), but on the last lap Stoner decided to use what he'd kept in reserve for the whole race and he dropped Rossi like a stone. Personally I think the handling of the Duc is not nearly the liability that it's being made out to be.

Perhaps the focus should be more on the possibility that Stoner has learned how to ride a tactical race? Either way, the other teams should be worried about the performance of the Ducati.


You're right, once Stoner decided to check out, he was gone. But his top speed advantage had something to do with that. Rossi was having to do all he could to keep up and pass Stoner round the rear of the circuit, so I'm guessing that he'd used up most of his tires. Stoner, on the other hand, rode a brilliant tactical race, conserving his tires because he knew he had what it took on the home straight. So, last lap, he opened her up and let rip. If Stoner doesn't have such a huge speed advantage, then things could turn out differently.

And you're right about Stoner's maturity. If I were any of the other teams, I'd be terrified. Last year, Stoner was really fast, but could be relied upon to chuck the machinery at the scenery several times during the season, putting him out of contention. He's proved that he doesn't have to do that any more, which is very worrying indeed if you're Yamaha or Honda.

harsha
14th March 2007, 22:03
It remains to be seen how the Ducati's are gonna manage the twisty tracks....

Even last year,Ducati have had a good start to the season before tapering off(although helped by injuries to the riders)

tha_jackal
15th March 2007, 00:23
I also think Bridgestone seem like the tyre to be on aswell.. Stoner was on medium compound tyres wasnt he? And he still ripped out the best lap of the race on his last one, whilst gapping Rossi in the process :eek: ;) :up:

The Phantom
15th March 2007, 02:38
I think I saw a graphic showing Stoner and Rossi on the same tyre compounds (can't recall what they were, though).

I can't wait to see Hopkins ride without injury! and I hope Vermuluen (anyone else have to look up the spelling of his name each time you write it?) can also get to grips with the bike, which is obviously far more suited to the 800cc motor than the 990.

9 days to Jerez! Must... remember... to... breath... : )

leopard
15th March 2007, 06:02
I hope that's clear, but I'm not sure whether I explained it well enough...

That's clear now, you and he, actually explained well, a compromise how to make top speed fairing but it also won't be troubling you in the chichane.

I saw from Lossail race that has such long straight, Honda Gressini and LCR didn't use full cover engine on their bike, This might be the reason Melandri and Elias who were amazingly running their bike at the front in firt few laps can't stand their position longer, wrong choice of fairing.

This could be their strategy using that fairing, besides maybe they don't have main partner to put their product on bike, as a result of Fortuna and tobacco in general have said good bye to motogp.

tha_jackal
15th March 2007, 07:42
Its Vermeulen, Phantom..

NinjaMaster
15th March 2007, 14:10
Its Vermeulen, Phantom..
He should shoot his spellchecker, hehe. :)

It's all academic but Stoner rode to the Ducati's strength (top speed) and conserved in the twistier sections where Rossi rode to the Yam's strength (handling) but the Duc's strength proved stronger. Had the Duc not had such a top speed advantage, there's every chance Stoner would have pushed harder and been a top chance to win anyway, given how he loves the track.

Stoner ran medium Bridgies and Rossi ran hard Michelins.

T-D
15th March 2007, 15:16
it's a technical discussion, so i have nothing to add other than a thank the group for their good input. this thread is a really good read.

Donney
15th March 2007, 18:18
I agree with T-D very good thread!!! :up:

Kropotkin
15th March 2007, 21:10
I think I saw a graphic showing Stoner and Rossi on the same tyre compounds (can't recall what they were, though).



Stoner was on mediums, but Rossi was on hard tires. But they're a little hard to compare, as Stoner was on Bridgestones and Rossi was on Michelins, which have totally different rubber compounds and carcase construction. Rossi was also using the 16" front, further complicating comparison.

Oh yes, and I've said this several times over the winter, but Hopper is on fire. If he stays healthy, he will win a race before we get to Brno.

tha_jackal
16th March 2007, 00:25
Oh yes, and I've said this several times over the winter, but Hopper is on fire. If he stays healthy, he will win a race before we get to Brno.

So long as he's fit.. I've heard he's discovered another broken bone in his wrist that was undetected.. So it could be a while before he's 100%.. Which is a shame..

The Phantom
20th March 2007, 01:40
Have many of the teams gone back to 16" wheels?

Kropotkin
20th March 2007, 12:34
As I understand it, everyone who is on Michelins. Michelin is only supplying 16" fronts now.

The Phantom
21st March 2007, 01:06
Perhaps the ever-improving technology now means you don't need to go for the 16.5" compromise... or maybe it's cost-related, to do with the new tyre rules.

I now have "Vermeulen" written on a piece of paper taped to my LCD screen : )

Only 4 more days to go! Must... remember... to... breath...

Kropotkin
21st March 2007, 01:16
If you take a close look at the tires, they are actually quite tall. So the actual diameter is not much different to the 16.5" tires, it's more about the construction, and the shape which the reduced rim diameter allows the tire to take.

leopard
29th March 2007, 09:27
It likely Repsol isn't the only one bike didn't use full cover of engine. I see all honda powered bikes use this typical fairing, which the engine clearly visible from side, for their aerodinamic.
Is this a Honda policy this year or they (and maybe the rest teams) have been using it from seasons backward, I might coincidently watch it now.

Kropotkin
29th March 2007, 09:57
Is this a Honda policy this year or they (and maybe the rest teams) have been using it from seasons backward, I might coincidently watch it now.


Yes, it's the new Honda design philosophy. There are lots of good reasons for doing it, including extra engine cooling, and some bad ones, such as poorer aerodynamics.

leopard
29th March 2007, 10:07
From my traditional knowledge about street bike of Honda, they perform when getting heat better than other bikes, most of bike will have powerless while honda performs the way other around.

They have to calculate the plus and minus of the new fairing design acurately. They don't have mayor problem about cooling system, on the other hand they need more beautiful aero-device in order to be agile more in the chichane, like...ops Yamaha.

Well motogp maybe something totally different.