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Back to the Future?

11312 Views 54 Replies 17 Participants Last post by  john
That was a good one Bob!

You're spot on in your suspicions of Japanese innovation. Of course the Japanese are copying HD for there dual shocks and flexy frames. You see, it's just like the proverbial broken's always correct twice a day! By doing nothing, HD has been rewarded and vindicated for their superior design, it just took the Japanese, Italians, and everyone else 20 years to realize the error of their ways. In another 20 years, the venerable pushrod will be hailed as the next revolution in racing technology, HD simply has to hold tight until then.
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So, in 40 years, valves will be back in the cylinder (iron ones of course), we'll switch to more efficient 6V charging systems, and also realize the full performance potential of mechanical vs. digital ignition systems.

Oh yeah, tubes in tires will be found to help balance rotating inertia abnormalities...


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When will the Japanese and Italians ever learn (from HD) the saying goes "they just don't build things like they used to".
Make fun if the Edge family all you want, but they get invited to major product introductions while you sit at home, waiting for the snow to clear enough so you can clean the oil spots in your car port.
Maybe "they" get invited to things, but as for sitting at home, waiting for the snow to clear...

Gee - went riding today, temp was around 70F, same for tomorrow (maybe a tad warmer). Going riding tomorrow too - of course before I do, I'll check my driveway as you request and look for any oil spots. Oh wait - the bikes are in the garage and oh yeah, they don't leak either.

Hmmm, you were saying???

I've got the time written on this piece of paper...
More than one reason for doing this

"...the twin shock layout is a concept being developed jointly with their subsidiary Öhlins and is intended to better permit controlled chassis flex..."
It's not really clear, to me anyway, from the information Yamaha has posted that the twin-shock arrangement is directly related to frame flex. They do say that using twin shocks gives them freedom to play with the rear swingarm and its relation to the "experimental," flexible version of the Deltabox chassis they are using.

I'm pretty sure that within the last year or so Kevin Cameron (in his Cycle World column) said something to the effect that twin shocks would eventually come back into favor. Anybody got a cite for that?
I believe what appear to be damping rods are part of the frame flex data aquisition system
What they didn't mention

Yamaha is also testing a Wide Glide front end with 34 degrees of rake to improve straight line stablity.

The forward controls also really allow the rider to stretch out during those long races.
This probably is some form of horizontal suspension. Maybe they have the rear swing arm on a pivot, the hardest thing to control them would be the chain alignment when the swing arm is out of position. The swing arm would only need to pivot a degree or two. This way when the front tire hits a bump it could track over it as the swing arm pivots to keep the tire profile at ( or about) the same contact patch.
Re: More than one reason for doing this

I am sure you are right that the twin shocks DIRECTLY do not have any effect on frame flex. My guess is that it is a matter of where the shock loads feed into the frame.

I used to keep all my Cycle World (and other) magazines, but my wife finally cracked down -- in exchange for her "allowing" me to subscribe to 3 motorcycle and 3 car magazines, I have to "agree" to throw out the old issue when the new one arrives. If anyone has anything by Kevin on this, I would be really interested in seeing it.


Interesting commentary on flex in the frame, but, if you've been keeping up with Ducati, you'd know that they have been working with the concept for quite a while. They have engineered flex into their frames while building stiff suspensions as it allows a more predictable response than the other way around. And they are moving to twin shocks in some cases as well, since the single-sided swingarm is proving problematical on some of the bikes, even though it allows for faster tire changes. The "tuned flex" of the Ducati frame is one of the reasons that it works so well. I guess that the concept must have some validity, as they have done OK on the WSB circuit.

I had considered that, and had also read other comments to that effect. However, it seems like far too substantial a member to be simply a measurement device (although there is some sensor attached to the strut on the left side in one of the photos). You will note in the photos that the sensors for measuring rear suspension travel are much smaller.

Also, the comments in the Yamaha site indicate that they are dampers:

"Featuring two main damping units across the top of the main chassis this concept explores the flex characteristics of the alloy frame and is targeted at improving rider feel."

Of course, the factory would never release information that would mislead us (or their competitors) now, would they?



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I believe you are absolutely right, and I had considered including some sites related to the Ducati's "controlled flex" and the new double sided swingarm, but decided that would be too much for this article.

Changing the subject slightly -- I am going to stick my neck waaaay out and predict that Ducati take both rounds of today's WSB at Valencia!


I'm not "really" making fun of Dirck (well, maybe just a bit, but in a good natured way). I read his site pretty much every day, and I thought his feature on the M1 prototype was good enough that I chose to link to it.

The snow is mostly cleared today, and I am almost tempted to fire up the Ducati and take an (illegal) shakedown run around the backroads, but there is a very muddy 1/4 mile of dirt driveway, and the Duc is still wearing slicks. Guess I better stay home and watch the WSB races on the tube instead.


Re: What they didn't mention

They *are* copying another traditional Harley feature -- longer wheelbases. Kevin Cameron first reported that he had surrepitously measured the RCV wheelbase and found that it was at least 3" longer than what had been used previously. Experts believe that all the new, specific to 4-stroke, chassis are using longer wheelbases. For such powerful, light bikes, acceleration is wheelie limited rather than traction limited, so the only way to get more acceleration out of a corner is to stretch the wheelbase.


I think the name should be changed to WDE, i.e. World Ducati Exhibition. Wake me up when it's over. Here's hoping that Honda has some competition in MotoGP, otherwise it'll be nearly the same, except that the wins should be more evenly distributed amongst the Honda riders.
World Ducati Cup

I was pretty impressed with the Corona Suzuki today. Raced much better than they qualified. Given a bit more development, they could at least get this thing on the podium.

The Petronas also was pretty impressive. If they get the hoped-for new motor with more power, they could be pretty competitive by the next round at Phillip Island.


Re: What they didn't mention

Geez, next thing you know, Rossi will be wearing arm chaps.

We're sunny and 70 today but alas I will be taking my son to a classmate's 6 year birthday party.

I guess my project of putting my Electra Glide front end onto my Ducati will have to wait.
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