$72,500 Ducati Desmosedici RR

Just got the December issue of Motor Cyclist (a damn fine publication IMHO).

Nice to see that the Italians have finally seen the V-4 light. I would love to hear what the Desmosedici sounds like.

But having done a valve adjustment on a 2000 Monster 750 4 valver, I get a little dizzy and nauseous thinking about the valve adjustment on this beast... 32 valve shims?!? Good thing the first few scheduled maintenances are free! For $72,500, they should deliver it to your door in a custom made Rolls-Royce panel van!!!:biggrin:

 

Imagine doing the valve adjustment on a NR750 Oval cylinders/32valves sweet jesus ..

 

Here ya go.. have fun drolling, just make sure you have a rag close by.

http://video.google.com/videoplay?d...=18&start=0&num=10&so=0&type=search&plindex=0

 

It must be because it is Friday afternoon and my thinking is murky, but 4 cylinders times 4 valves per cylinder equals 16 valves. Where does 32 come from? is it the desmo structure, one to open the valve and one to close? I haven't taken one apart so I haven't sen the layout.

Thanks,

John

 

Just what Motor Cyclist said... i couldn't figure it out either.

Apparently you have to drop the engine to do it, too...

 

Thought there was a slip there too, as it is the NR750 that has the 32 valves

 

There is a really good article of the Ducati Desmosedici RR in a UK rag this month (Fast Bikes - pays to have friends overseas). Hopefully the Ducati Desmosedici RR does not have rocker arms that wear prematurely (some older Ducati's suffered from premature rocker wear - 916 in particular). Ducati has been promoting the fact that their bikes have fewer parts and the maintenance schedule is better for their newer bikes. Regardless of the price check this directly from Ducati: "PRODUCTION AND DELIVERY SCHEDULE
Reservations for the Desmosedici RR have been accepted via the official Ducati dealer network since 2 June 2006. Production of the 1500 limited edition motorcycles began in October 2007 and first deliveries are reserved to 999R owners who placed their Desmosedici RR order before 30 September 2006. Production of all remaining orders will be completed by December 2008". Funny this post came up as I have been recently oggling over a Ducati 916 that is for sale in my area.

 

I'm hoping there will be one at the Seattle Motorcycle show thats here in a couple weeks so I can say I sat on one...:biggrin:

 

I have a friend that is getting one. I think I'm more excited than he is! LOL

 

I read an article about Motogp this season in TWO... Honda and Yamaha are now developing new valvetrains based on the Desmo setup because the valve springs can't take the rpm anymore. When they switched to the 800 the performance drop off when the valvesprings couldn't close the valve fast enough forced harder springs that would crack before the end of the race!!! Nicky's bike blew up in practice right in front of the Ducati pits once and the culprit was the valvetrain. The power and rpm for that extreme are just too much for valve springs so supposedly Kawasaki and Suzuki are much farther ahead in the developement and I wouldn't be surprised to see "Desmo" valvetrains in the Big 4's futures for the street if that happens.

 

Ducati was not the first to use a Desmo system. In the 30s or 40s, not sure here, Mercedes had a desmo setup in one of their formula cars. Apparently you could spin the whole valvetrain with your fingers, when the head was on a bench. Way cool! There may have been others as well. Ducati just popularized its' use, and indeed, put it to good use. I don't think there is a patent. Maybe on Ducatis actual mechanism.

 

Not only have they seen the light, they have put it on Honda's face by beating them at their own game! :wave:

Certainly not a practical bike - but it's not about practicality.

 

I just grabbed the magazine, and the 32 valve shim reference is in Brian Catterson's editorial, not the article for the bike. Here is the quote:
"The good news is the $72,500 asking price includes three years of free service-excellent when step one of the valve-adjustment procedure reads "remove engine". Never mind that 16 desmodromic valves, each with its own opening and closing rockers, add up to 32 shims. That can make for lots of hours in the shop at $75 per."

The original reference was not for the the NR750. Although I assume that that bike also has 32 shims, provided that it has a traditional shim adjustment. Never seen an NR head, so I can't be sure.

 

Sounds to me after a quick read theres one shim for opening and one for closing as it's actually two different mechanisms, make sense now that I understand the workings. Still, whatever it is, it's working for Ducati, that baby sure does sound familiar.

 

:wink: Makes our valve adjustment at 16000 miles not so bad after all

 

It is 32 shims.
One cam set opens the valves one set closes them....that is desmo. Each follower has an open and close shim.
When engines turn in the teens of thousands of RPMs the valves build up enough momentum that the spring floats in the open position even though the cam profile is calling for it to close. You can stiffen the hell out of the spring, to a point, to avoid this but you're robbing HP from the engine just to overcome the spring forces and drag on the cams. If you positively open and positively close the valve with a follower pushed from both sides you effectively get rid of the issue, albeit with some more rotating mass in the head.
And yes, F1 has been ahead of this game but only the duck brings this maintenance nightmare to the street. That's IMHO, as any streetable powerplant should be able to get away with springs.

 

Yeah... desmosedici means 16-valve in Italian... and I though Ducati went from singles, to a v-four, and then to the twin? This is not new for them, entirely.