What’s the deal with the Yamaha M1′s new triangle frame?

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On Tuesday, Italian site GPOne snagged a image of the 2013 Yamaha YZR-M1 sans-fairing. That revealed an entirely new frame arrangement that departs from the traditional twin-spar aluminum affair or “Deltabox” as Yamaha, which helped pilot the design, calls it. What gives? We asked a MotoGP designer.

“From what I can tell, this is just a further evolution of the basic double beam design favoured by Japanese manufacturers since the ’80s,” explains that designer, who prefers to go un-named.

The 2006 YZR-M1 employed a much more traditional aluminum beam affair.

“In any structures design, you want load paths to follow the shortest, most direct route. In first generation Deltabox design, the tall and wide motors of the day required the frame beam to either (a) curve significantly outward (along the Y or lateral axis), or (b) be L shaped, with a vertical member rising up from the swingarm pivot to meet the longitudinal spar coming back from the head pipe.”

The red line demonstrates the load path through an old FZR750′s Deltabox frame. That left turn over the swingarm pivot is far from ideal, but necessitated by packaging the tall, wide inline-four.

“As motors became more compact and engine architecture evolved, such as shortening them by stacking gears and crankcase, the angle between the longitudinal beam and vertical member decreased, shortening the load path.”

“This M1 suggests that Yamaha has gotten closer to the ideal, which is a beam structure that goes in a straight line from head pipe to swingarm pivot.”

“This image of the ’13 M1 says more to me about the engine and gearbox than it does about the frame. “Clearly Yamaha has been able to make the most of the computational analysis tools available now to build the best packaged 1000cc inline-4 in history, and craft an ideal frame for it. The picture I want to see is of the motor and transmission…”

  • rohorn

    The red arrow #3 is pointed at an engine mount bolt rather than the swingarm pivot, right?

    Trivia: I don’t know why Yamaha gets credit for the “Deltabox” frame – JJ Cobas made them first. Yamaha does get credit for marketing them.

    More trivia: Some older Bimotas ran the frame beams from the steering head directly to the swingarm pivot. Too lazy to look up which one(s).

    What I would really like to know is if areas of the frame marked “A” and “2″ are a lot thinner than previous practice. That would allow the steering head to flex more on one axis yet be very stiff otherwise.

    • http://RideApart.com/ Wes Siler

      Correct, the swingarm pivot is that gold-colored mount.

      No way to know on A and 2 thickness, but that seems to be what’s going on based on educated guesses.

    • VR

      Antonio Cobas will never get enough credit for his work.

      Twin beam chassis, antidive forks, first FI racing bike, to name just a few of their creations.

      The steering head to swingarm pivot frame beams can be clearly seen also in this KTM powered Kobas JC2 from 1986

  • Aaron L

    From a mechanical engineer with a background in structural composites and vehicle dynamics (myself):

    The comments on an ideal load path are pretty well put. That’s the whole idea with a composite monocoque- you can spread out your load, not only distributing the stress in each element of the structure, but also creating a simple load path.

    The new M1 frame with the huge triangular shape is most likely a compromise between size and wall thickness. Since they have created a larger perimeter-frame-area, and say don’t change the wall thickness, then their frame is now stiffer with a lower stress (as a result of the larger moment of inertia, see equation for bending stiffness of a beam below). However, I doubt they would make a heavier frame for increasing stiffness and decreasing stress below the allowable….so what they probably did was lowered the wall thickness to make the frame weigh overall as much as the old one (after analysis and compromise, obviously) and increased the stiffness.

    That being said, I wonder what factors of safety they are running, and what alloy of aluminum they are using that holds that strength while being weldable….2219?

    (Equation for beam bending stiffness)
    δ_max=P(L^3)/3EI

    …the higher the Inertia, the lower the deflection (higher stiffness).

    Tune in tomorrow for a lesson on overall lateral spring rates of motorcycles!

  • Frick

    My take, based upon where the swingarm mount is still located… They found a way to keep the same rigidity parameters as the past, in a package that uses less material = less weight.

  • Porter

    Is that a 4-3-1 header?

  • rashomon_one

    The alloy for this frame is very likely a Japanese variant of one of the weldable 7000 series alloys , such as 7003, a silver-containing alloy tailored for high-end bicycle frames (1/2 a percent of silver improves the properties of almost any aluminum alloy, at a very significant cost hit). Or, if stiffness, rather than stress, is controlling the design, there’s a chance it may be one of the middling strength, high-elongation 5000 series alloys, which have been used a lot in racing frame construction.

  • http://twitter.com/mchale2020 Jordan

    Does anybody else think the next generation R1 might feature a counter-rotating crankshaft and appropriate balance shaft setup similar to what the M1 uses?

  • yipY

    The fat red line “load path” on the FZR image is entirely incorrect.The highest “load paths” on a road bike frame are from the centre of gravity of the motor to the steering head,swingarm pivot and the engine bolt closest to the drive sprocket.The idea is wrong that GP bikes are on a never ending quest for increased strength and rigidity:they are not.If GP chassis had to be as rigid as a machinists mill they would be CNCed out of one big block of ally.Rigidity is not the major concern in a GP bikes chassis construction,it is that somewhat undefinable quality called:”feel” that allows the rider to be able to judge the amount of throttle they can use consistently and safely.I’ve got my own theory on why Yamaha is using the more compact “TriangieBox” and I’ll mention it to Jerry when I see him again.

  • http://twitter.com/clreedy21 Chris Reedy

    Seems like a lot of people are fixated on the frame but a big unknown is how much of a role the engine plays as a stressed member and the packaging dance that surrounds that. Use the 1199 as an example of a situation where there is no frame, just an engine with sub-frames attached at either end.

    Something that has been mentioned in the discussion here is the frame stiffness and the “feel” of the bike. A rule of thumb I’ve heard used by some chassis designers (4 wheel) is that the chassis is to have a torsional rigidity at least an order of magnitude higher than any of the vehicles desired roll stiffness values so that the chassis isn’t a meaningful part of the equation. For these bikes the balance of rigidity is key to providing a good feel and predictable characteristics to the rider.

    One good example would be the design the the triple clamps which are desired to be extremely stiff in the longitudinal direction for braking yet somewhat compliant in the lateral direction since at full lean angle the deflection in the system is an operable (if perhaps not measurable) component of the suspension. This is where the feel of the rider comes into play. The rider likely can’t identify that the triples are too stiff, but he can communicate to the engineers that the bike is nervous and chattering through corners at the limits of lean angle yet seems composed at lesser angles. Once you get this feedback a good engineer can track down and identify what parts (or systems) could produce this phenomena. Then a really good enginner will figure out a way to eliminate this feeling without mucking the rest of the bike up.

    • yipY

      Car chassis tech is virtually irrelevant to motorcycles,period.The Panigale chassis is a retrograde step in track performance housing a Ducati twin compared to the space frame and nowhere near GP bike standard.I have never ever heard of creating GP grade triple clamps with any degree of flex and I knew the guy who invented the multi bolt triple tree.A degree of controlled flex in the frame and swing is often designed in by the chassis experts.

      • rohorn

        I guess that’s why both the car chassis and motorcycle chassis engineers are describing stiffeness in terms of resonant frequency rather than degrees of torsional flex/nm. And that stiffness has LOTS to do with front end chatter – get the 2 too close together and you have big problems.

        Ask the guy who “invented the multi bolt triple tree” why 2 racers (Both championship winners in different years) of the Yoshimura Superbike team had different clamp setups – one racer preferred the twin bolt one, the other racer preferred the triple bolt one with the middle bolt removed. Take a good look at the evolution of the Yamaha GP top clamps – tell me why the slots in front of the stem are there, and why they keep growing – hint: It isn’t for weight.

        Could go on, but I think you are a post whoring dumbass troll with no clue about any of this. Besides, don’t the internet experts like JFC1 and you belong on the Cycle World comments section?

        • yipY

          Car tech is irrelevant to GP chassis,period.I think you are assuming why the two different Yoshimura racers ran different bolt arrangements and it may have had little or nothing to do with flex:further study is advised.The balance of the harmonic and non-harmonic responses to stress effects in the tires and chassis are the issues that need to be addressed in a winning GP chassis.Resonant frequency less so.I’ll ask the guy who has handled Honda,Ducati and Yamaha motoGP top triples in the pits for years about your theories next time I see him.If you are this abusive and easily goaded into bristling fury on a mere message board by learned opinion it would great sport to see how you would react to being next to our pits with my mind game antics and riders winning 1-2-3 on a racetrack.

          • rohorn

            Psst – Jim Varney died a few years ago. Put away your script for “Ernest Goes Racing”.

            • yipY

              Let a man be known to the world by the words he utters:”Could go on, but I think you are a post whoring dumbass troll with no clue”.Abuse and assumption from(I guess) from someone who’s entire experience of a motorcycle race team is begging for stickers or t shirt merch at the roller door.

              • http://twitter.com/clreedy21 LongTravel

                Ok, so know that after I’m done embarrassing you here that you’re probably going to be better off and you’ll hopefully come away a better person.

                First I’ll address your assertion that car tech is irrelevant to GP bikes and to do that I’ll admit I didn’t really make it clear. My point was that that there are reasonably well defined targets for frame stiffness values rather than simply shooting for “all that you can get”. You’re right that 4R thinking almost certainly doesn’t apply to 2R designs but the underlying notion that you want to isolate your variables does. Instead of having to tune the stiffness of both the frame and the components that bolt to it you want to make a frame that is sufficiently stiff such that it isn’t a contributing factor to the equation then tune the other bits. If you can’t get the compliance you need without using the frame then you can re-visit that design with the intent of introducing some new characteristic, but in the end it’s vastly simpler to only have to modify the smaller, simpler, easier to manufacture pieces. An example I could have used would be the tuning of frames on motocross bikes by grinding material away from the welds to decrease the frames stiffness. This is a good example of a situation where the chassis component design was advanced to the point where a frame modification makes sense.

                Next I’ll touch on your wikipedia level knowledge of stress inputs and simply point out that, in fact, they ALL matter and for the most part are directly related.

                Finally I’ll address your assertion that GP clamps don’t flex. You’re absolutely kidding yourself and borderline delusional if you aren’t aware of the amount of deflection you’ll get out of all manner of components on a GP bike at race pace. Literally everything in this world moves a bit when you push on it and unobtanium GP bike parts are no different. Now as far as tuning the stiffness and deflection characteristics goes there are multiple schools of thought like I pointed out above. I don’t know what your man in the pits who is apparently the official “Top Triple Clamp Handler Guy”, but in the case that I am familiar with the design lent itself to altering the stiffness through the triples rather than modifying the much larger, complex, expensive, and difficult to manufacture frame. At least that’s what the engineer who designed it told me while pointing at the ribbing in the part. I could walk over and ask again since the part that he discussed with me is literally sitting on his desk.

                Go back to trying to impress and confuse guys on your local track day forum, you’re outgunned here.

                • yipY

                  When I stand next to Jeremy Burgess again I’ll ask him about designed in flex in triple clamps.I found out from him the reasons why the motoGP Ducati design was so bad compared to the Honda and the Yamaha.Quote:”Go back to trying to impress and confuse guys on your local track day forum, you’re outgunned here.” I wonder if there is as much animus and assumption when you are faced with an engineering challenge.I haven’t seen Rossi’s crew at the local track days much,I understand they race at other places here and there.

                • http://twitter.com/clreedy21 LongTravel

                  Cool story bro. I’ll try to remember it the next time I go to work at my job as an R&D engineer.

                • yipY

                  We have a Motorcycle chassis expert? Not really.I guess the last time any vehicle he has altered qualified for anything,was a little hog farm quad for a tax concession or zero rate finance.

                  “I focus on developing frame components new and replacement models of Honda ATV’s ”

                  http://www.linkedin.com/in/clreedy21

                • rohorn

                  He’s still an engineer with Honda – you have increasingly proven yourself to be nothing more than a child with internet access.

                  Idiot trolls like you are one big reason why guys who really do this stuff for a living seldom show up on internet discussions.

                • yipY

                  …..the last time you two fellah’s race team with three riders in the pits won 1-2-3 was? I sure seemed like really doing stuff at the time to me.The prize money was an illusion I guess.The last time I checked HRC did not mod quads for Pedrosa.

                • LongTravel

                  Since you’re so keen on identifying and discrediting us why don’t you just identify yourself then?

                  Also I’ll just leave this here… http://www.insidemotorcycles.com/component/k2/item/400-controlling-flex-in-motogp.html

                • LongTravel
                • yipY

                  The motodna article is entertaining in an internety way.It does not address the “the inherent big mistakes in the recent Ducati configuration”.

                • yipY

                  The article does not address the inherent big mistakes in the recent Ducati configuration.Playing with flexy clamps will not effect the big problems that Ducati will not spend cash on fixing.

                • rohorn

                  I thought it was bad form for the umbrella girls to interfere with the crew at the track.

                  Nice name dropping, troll!

                • yipY

                  Deleted posts remain to view in the pages code guys.Even pit girls know this.

        • yipY

          rohorn’s opinions and unparalleled chassis engineering knowledge are wasted on discussing motoGP ‘s mere metal motorcycles.This link may clarify things somewhat in peoples minds :http://velokos.com/index.php?id=259&p=2&search=&editor_id=5 .To quote the Roadrunner:”meep,……meep!”

          • rohorn

            Yes – now you know what I do to relax and get some exercize while I’m, at it.

            So what’s your point?