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Ducati Cries Uncle . . . Will Test Japanese-Style Twin-Spar Aluminum Frame Next

The frustrations of Ducati and Valentino Rossi continue.  Bolting an aluminum front section on to the engine (acting as a stressed member) for the Aragon race last weekend did not provide the improvements hoped for.  It turns out that Ducati has already developed another alternative, i.e., a twin-spar aluminum frame similar to those used by the Japanese race teams.  This frame does not incorporate the engine as a stressed member.

The new frame will be tested for the first time at Jerez later this week.  Presumably, Ducati has its eyes on 2012 and the 1000cc bike at this point with only four races remaining in the current series.  Whether we will see the new frame design raced this year is a question as yet unanswered, but don’t be surprised if the 1000 cc bike is raced next year with a decidedly un-Ducati like twin-spar aluminum frame.

41 Comments

  1. joe b says:

    sad to hear rossi say it wasn’t his fualt he fell, blaming Lorenzo and Spies, in the first turn at Motegi. dont they know, to get out of his way?

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  2. Raymond says:

    Steel trellis is too inconsistent to manufacture, and is too heavy, but most of all it is too stiff. Frames NEED to be laterally flexible (side to side, not length wise) for it to perform well when the bike is on its side in a corner. A motorcycles suspension does not work very well when going over a bump when the bump is leaned over at 50 degrees lean angle or more. Instead, the frame acts as the suspension, and if it is so stiff to not be able to flex while hitting a bump, this results in loss of traction.

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    • DynoSoar says:

      Actually Raymond, seems to work OK on Checa’s Superbike and a few other world championship winning motorcycles – be careful about your absolute statements when it comes to the balanced compromise that is motorcycle Engineering.

      Steel has some advantages as the flex member in a chassis. The high fatigue loads it can withstand and the small volume of material needed to carry the loads around other components often make it easier to acheive a desired flex response and damping characteristic within a limited space and geometry, especially when prototyping.

      I strongly suspect that the challenge here is that the relationship of flex and damping to feel is still something of a black art in motorcycle design. With tyre technology changing continuously, and a (currently) conventional aluminium beam chassis being the level playing field that offers the same performance compromise to every team, I applaud Ducati’s efforts to find some breakout approach that will move us forward to the next level. Unfortunately, they have clearly found some blind alleys the last couple of years.

      Let’s not forget that people laughed at Colin Chapman and his ilk when they suggested that all chassis movement in a car should be in the suspension, but that idea opened the door for precision geometry and wider tyres. The fact that a similar approach patently won’t on a motorcycle is what makes bike chassis design so much more complex and interesting – and with so much more opportunity remaining for breakthrough changes. I have to wonder what the team would be building now if John Brittan had lived a little longer…….

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  3. joe says:

    Actually, from what I understand, Ducati hasn’t been using a full-length frame this year. They’ve gone from the steel trellis frame to a partial carbon front section that bolts to the engine in front and incorporates the steering head and air box with the usual through-head induction. The swing arm bolts through the engine case at the rear.
    They were hoping the aluminum replacement at Aragon would improve handling characteristics and feedback. That’s what Rossi said. Guess not.

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  4. idjiots says:

    Some food for thought. Steel and aluminum will have different resonant frequencies. As will the trellis vs a beam design. The change is not likely about weight. Far more likely is about the dynamic characteristics.

    Also, has anyone actually been following MotoGP? If so why don’t you know that Ducati already has been using carbon frames.

    Also see Casey Stoner’s opinon on the steel trellis frame

    http://www.superbikeplanet.com/2011/Aug/110830cs27.htm

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    • Norm G. says:

      re: “Also see Casey Stoner’s opinon on the steel trellis frame”

      just one man’s opinion (which he is of course entitled to), though he’s only won a SINGLE title with a half-frame design. why not more…? who knows, maybe casey simply couldn’t get on with steel…? much the same way vale NOW can’t get on with carbon…? guess it all evens out.

      but don’t stop there, we should probably seek the opinion of 7 others. especially those who HAVE won multiple titles. 4 have won 2, 1 has won 3, and 2 who have won a whopping 4 each. that’s 13 repeat titles all bagged with the supposedly inferior performance of steel tubing welded together. where some point and say “inconsistent”, a simple review of history shows nothing but “CONSISTENT CHAMPIONSHIPS”…!? the stats are overwhelmingly positive.

      just imagine if a compliant steel trellis had been wrapped around a 500 2-stroke engine that was competitive with the NSR’s V4…? honda’s grandprix history might look very different than it does today.

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  5. Jason says:

    Everyone is so certain that steel is inferior as a frame material to aluminum. I am not so sure. Structurally, yes aluminum has a good strength to weight proposition, but strength isn’t what keeps the chassis straight under a load.

    *Stiffness* to weight, steel starts to look a lot better. Steel is about 3x heavier than aluminum, and also about 3x as stiff. When you start looking at using thin wall tubing, steel looks even more valuable, because it is more forgiving of joining technique (welding) and less prone to brittle failure (especially fatigue failure).

    Carbon is an awesome material with all sorts of possibilities, but when they saw it wasn’t working, I am really surprised they decided to try aluminum. I guess the old version didn’t work as well as they wanted, but I would expect them to have a better idea of how to fix the old design, than starting fresh. They have built their reputation on lightweight efficient steel space frame chassis.

    “When in doubt, make it stout. Out of things you know about.”
    J

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  6. GP says:

    Kind of like KTM’s PDS rear suspension. It took a long time for them to figure out that being the benefits did not outweigh the deficiencies – in the eyes of the customer base.

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  7. MikeD says:

    Ok, that does it…let’s all band togheter and fly to Borno Panigale and throw eggs at Ducati’s Factory and DEMAND they give us back Das Trellis…(^_^)

    Seriously now, i for one think there’s still juice left to be xtracted from a Fruit called Trellis.

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  8. John says:

    Not sure if this can be done but why not make an aluminum trellis frame. Would offer weigt and strength advantages and stay with the Ducati trellis frame for which they are renowned.

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    • Norm G. says:

      i believe i’ve answered this question elsewhere. unfortunately it would NOT offer any strength advantages. not sure what the ratio is, but steel is many times stronger than aluminum so you wouldn’t be able to substitute an aluminum tube of like diamater in place of steel. aluminum simply has a better strength to weight ratio and even that may be hard to justify. with modern advances in steel tubing, design, and fabrication (not that ducati has explored ANY of this in production mind you), a steel trellis can be made nearly as light, but be exponentially stronger. what’s 2 pounds saved if you lose feel and your front end snaps off from fatigue after 6 months of use…?

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    • Goose says:

      Aluminum is roughly 1/3 the weight and roughly 1/3 the strength of steel. Since stiffness increases to the square of increases in diameter aluminum quickly gains an advantage over steel when tubes are big (e.g. beam frames). An aluminum trellis frame really isn’t a great use of the material. A Ti trellis might make a great deal of sense but aluminum doesn’t.

      FWIW, I read a long time ago that when 50 people are racing the same design everyone has 49 test riders to develop the design and find problems. When one person races a design he has to find all the improvements and discover all the problems. As long as Ducati has a unique frame they have have to do ALL the work. Running a design similar to other brands would make Ducati’s life a lot simpler.

      I can say it is true but I read recently that part of the reason Ducati had to move away from trellis frames has to do with an inability to get consistency, with all the joints and all the welds there are just too many chances for variation. Carbon fiber or (relatively) simple beam frames are easier to keep consistency from one to the next.

      Goose

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      • Norm G. says:

        re: “but I read recently that part of the reason Ducati had to move away from trellis frames has to do with an inability to get consistency, with all the joints and all the welds there are just too many chances for variation.”

        this would certainly seem like a reasonable statement, however it doesn’t pass muster when weighed in the context of 25 championship (count ‘em 25) in the last 20 years with 14 different riders (count ‘em 14) and 4 different framesets (count ‘em 4).

        all but 1 was taken down by MASS PRODUCED kit stamped with a VIN. and then there are the countless riders who may have never won a title, but jumped from ally onto a steel trellis and were seriously competitive…? ie. haga, biaggi, bostrom, chili, fabi, capi, laconi, mladin, xaus, etc… good god… at what point do we stop naming people…? not saying steel frames DON’T have inconsistencies, but another quality (as CLEARLY evidenced by all the wins) may be it’s forgiving nature that basically renders this issue moot.

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        • Goose says:

          Norm,

          Two significant problems with your point.

          First, those championships were (with one exception) in production based racing. The competition was stuck running chassis that are cheap to build, could be built by the thousands and work on the road. Lets also remember Ducati wasn’t racing on a level playing field for many of these victories, they were given both displacement and weight breaks and allowed to race very limited production models (50 units IIRC) while Honda, Yamaha, Suzuki and Kawasaki had none of these advantages. This is MotoGP, the rules are the same for everybody and the the other guys are running the best that they can design and build, not what they can get by the accounting department.

          Second, time marches on. How many world championships were won with air cooled engines? How many were won with carburetors? How about spoke wheels? Drum brakes? I could go on for a while but I think you get the point. There is a word in racing for people who think about the past. The word is loser.

          Goose

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        • Pete says:

          There’s a huge difference between production based Superbikes and Grand Prix machinery Norm. Having ridden and raced both I can vouch for that.

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          • Norm G. says:

            re: “There’s a huge difference between production based Superbikes and Grand Prix machinery.”

            WCE (worst comment ever)…! maybe 20 years ago in the 2-stroke era.

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      • Denny says:

        Absolutely: your rationel seems to be thought out. Trellis can never compete with ‘shell’ type structure, be it aluminum or steel. It’s beautiful and looks traditional, that’s about all. What is offering itself is a spacious tube-like structure. Steel is too heavy, so what is left is aluminum or composite while the former one has more chance to be stiffer. If I was to tackle this task it would look like extended ‘goose-neck’ (nothing to do with your nick) bolted right onto engine case. In fact I believe the best would be if the casing and frame was one and identical piece. That way the ‘stiffness’ would attain its highest value in given space. Conversely, to weaken it predictably for purpose of flex is well within current engineering tools capabilities. Some material to read on frame design is here:
        http://www.docstoc.com/docs/76698788/Motorcycle-Frame-Structure—Patent-7845451

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  9. Ken says:

    I hope they can get it together in time… I love rooting for Ducati…

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  10. Vroooom says:

    As others have said, I’m not sure there old steel trellis frame is such a bad thing. The aluminum frame sure didn’t work for Rossi at Aragon though, 10th place, never thought I’d see the day.

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    • brinskee says:

      He started from PIT LANE. Did you watch the race?

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      • Goose says:

        He started from the pit lane and quickly got into the top ten. He then spent the rest of the race fighting very hard to stay there, being passed by and re-passing less than top riders on second level bikes. His lap times and total race time were far off the leaders.

        Did you watch the race?

        Goose

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        • brinskee says:

          Pit lane AND a time delay of 10 seconds. There’s only so much you can do while being caught in traffic. Even if you’re Vale. I’m not saying the changes to the bike were good, but a penalty like that would be tough for anyone to overcome. What was the expectation, that he fight all the way to the top five? Come on.

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    • Norm G. says:

      re: “As others have said, I’m not sure there old steel trellis frame is such a bad thing.”

      2 decades and 25 championships can’t be all wrong.

      PS: checa’s 2011 title will make 26.

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  11. Tim says:

    If you can’t beat them, join them. The next design hurdle will be; How to get red paint to stick on Aluminum.

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  12. ze says:

    should go to the trellis where they have worked & many riders did well with it in sbk as well Bayliss and Capi in the 1st gp year, the perimeter alu frame will be hard to figure out without a good experience.

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  13. Mark Pearson says:

    My own random thoughts generated by Ducati’s frame issues:

    1) If making the motor a stressed member is the problem then why not apply the expertise they’ve developed in carbon fiber into a carbon fiber, perimeter frame?

    2) Why not revisit the steel trellis frame? I can’t remember where I read it but I thought a steel trellis structure offered a good balance of strength, flexibility and weight.

    3) As much marketing identity as Ducati is forfeiting trying to compete in GP I’m surprised they pulled out of WSBK.

    4) God I miss the 990 era.

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    • Stinky says:

      It would seem a carbon twin spar would be a good step. Maybe too late in the season to test or make? I’d hate to see them get out of GP as they’re the only company to offer a street legal GP bike in the Desmdici, but I’m not really all that thrilled to see(or pay for) this GP technology on a streetbike. They’ve done soooo well in WSB I think they oughta build on that. I think it’s better racing, at least this year. I’d love to see some of the GP boys in WSB. Biaggi would hate to see it, but I wouldn’t mind seeing Nicky in WSB. I too miss the 500s and 990s sliding around. Never will see it again though, whatta shame.

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      • Next year, GP is allowing 1000cc engines, so you will see the bigger bikes again. They are even allowing production-based liter bikes with prototype chassis on the grid.

        I believe Colin Edwards will be riding an R1 version.

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        • Mark Pearson says:

          It may be here where I read it, but one prediction is that the Cowboy Days (point-and-shoot) of the 990 era won’t be coming back due to the sophistication of electronic traction control. Typically I believe the less restrictions in prototype racing the better, however electronic traction control is one technology I feel has knocked the Rider/Machine scale out of balance. It’s the mechanical experimentation of the 990 era that I miss.

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  14. Gutterslob says:

    I hope “Uncle” sounds nicer in Italian. =P

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