A question about the GP8 and the older Trellis frame - Ducati.ms

agip_beta · Jul 26th, 2011, 8:47 am

Just a question. Could Ducati have Rossi (or another test rider for that matter) test the GP8 with the older Trellis frame? Is this against the rules? Was there a problem with the Trellis frame that made them switch to the carbon frame in 2009?

I know that this bike is now 4 years old, but would not testing it as a comparison to the current carbon fiber GP11 answer some questions?

Matt_P · Jul 26th, 2011, 9:13 am

seeing as the bike is technically eligible for current competition he can't test it. It's still an 800cc GP prototype.

The problem they had with the trellis frame is that they couldn't reproduce the exact same frame every time as the stiffness varied something like up to 15%.

Also, the real issue is that the engine is still an inflexible stressed member. Furthermore, you still have the problem of not enough weight up front with the 90degree V...

agip_beta · Jul 26th, 2011, 9:36 am

Thanks for the response. Why did it seem to work OK for them for the first 6 years? We saw Casey win in '07 with Capirossi finishing 3rd in the championship in '06 and lets not forget Troy Bayliss winning in Valencia that same year.

Was the frame a problem with the desmosedici from the start?

Matt_P · Jul 26th, 2011, 2:23 pm

^The duc always handled like shit, and until 2008 it got by on huge power...

They've been doing things wrong from the start IMO, and the 800cc corner speed style really shows that. At least the 990 could square the corner off and get monster drive out of the corners.

NSP · Jul 26th, 2011, 3:25 pm

they also still had custom tires from Bridgestone then....so they could tweak the compounds as the season went on.

The spec tires dont seem to be a good fit for the Ducati

Matt_P · Jul 26th, 2011, 11:38 pm

^true dat

Jyrki · Jul 27th, 2011, 4:44 am

Talking bout the grunt the engine has now. It's powerful engine even if not blasting past others on the straights like the 2007 model did. So enginewise they are still good.

tye1138 · Jul 27th, 2011, 1:04 pm

The trellis frame and aluminum swing arm had TOO much flex. If you watch any of the older bikes, you will notice the bike flex all over the place coming out of corners, it was a huge problem. The resolution was to go carbon fiber with the upper part, replacing the trellis.

As someone else pointed out above, there is a slight coincidence that Ducati changed frames right when the single tire rule came out. The tires changed and this change is I think what threw them off guard. You will notice stoner start to have front end crashes right away in 2008 during practice and of course lost the championship to Rossi due to crashing in races.

I think the trellis idea is not a bad one. They could for sure pull out a 2007 machine, put Rossi on it and see what happens. The trellis upper mixed with a carbon fiber back end and swing arm, is not a bad idea. Its fairly easy to stiffen up a trellis frame, yes it would be heavier but for the purpose of testing, why not?!

Matt_P · Jul 28th, 2011, 4:30 am

^Maybe the heavier trellis would put enough weight over the front too...

ducatimike · Jul 28th, 2011, 10:40 am

The current CAD technology allows engineers to not only design in 3D but also test mechanical properties of the designs. I dont understand how Ducati could have gotten themselves into such a mess with the current technology available. The stiffness of the bike could easily be determined whether frameless or using a trellis type. I would think the engineers could come up with many different designs, evaluate them on the computer, then pick the best design and build a prototype and then evaluate, tweek, and improve. They seem to be lost as the bike is getting worse!

Was watching the race from the grandstand at turn 4 this last weekend, and the Yamahas and Hondas looked so smooth and fast. On the contrary, Valentino and Nicky seemed to have there hands full trying to control their bikes.

Sometimes you come up with an idea and you think it is the answer to many problems, but as you get into the design and testing you realize its not such a good idea. But then you are somewhat committed and you have gone so far down the road that is difficult to change directions. But sometimes you have too. Ducati is at a crossroads here and needs to make a decision soon, cause what they are doing is not working.

Mike