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-   -   2009 Husaberg (http://www.gasgasrider.org/forum/showthread.php?t=1708)

gasgasman 11-13-2007 08:44 PM

Quote:

Originally Posted by GMP (Post 9978)
I can't get over how they came up with moving the crank back offsets the increase in height. Interesting.


The live photos really show how high the crank shaft is. That's a lot of rotating mass to be carrying that high, IMO.
It's all a gimmick.:cool:

GMP 11-14-2007 07:28 AM

Yes, a large and high speed rotating mass, not like a couple of hollow camshafts in a YZF. There must be more to it. I'm sure the design had to be reviewed, presented, and approved for KTM to bankroll the thing. Then again, they are still playing with the PDS shock and after ten years will not admit defeat.:eek:

barkeater 11-14-2007 08:36 AM

I'll pull my paragraph from the other thread.

Everything I have heard so far leads me to believe that with the fuel under your butt and all the motor mass between your calves, the bike should handle like a dream - even though it is more top heavy - the weight is in the right places as you sit on the bike. It supposedly corners like a corvette. Not to mention that large open area behind the front wheel where the smashy parts all used to be. It will be harder to flatten a header or rip off a cooling line on rocks and log crossings.


The Husaberg PDS is NOT the same as the KTM. It works. I suspect you will see KTM moving their line to the Husaberg set up in the near future. KTM has been using Husaberg to experiment with the fork settings for a few years now. The 550 and 450 Husabergs I rode all handled on par with my Gasser. IMO, the 'Berg is the 4 stroke equal to the 2 stroke Gas Gas.

GMP 11-14-2007 12:13 PM

It could be that the overall effect of both the higher/rearward crank and lower fuel cell is a lower CG and an improvement in turning. I just think its interesting and would like to see the numbers behind it.

On another subject, why no 'Berg 250F?

barkeater 11-14-2007 12:40 PM

What will they sell everyone after they buy the 450?

That's the next hot rumor in the Husaberg world - the 250. They've had an awesome 380 kit since 2005. Something between 250 and 450 would be great. The logic is that Husabergs are not starter bikes and anything under 450cc is for beginners.

Really, the current 450-550 'bergs feel like a GG300. The 650 handles the same, but "feels" different.

I can't wait to get a leg over one and see.


I still like my EC200 the best of any bike I've been on since my first Italjet mini-mini from 35 years ago.
http://user.icx.net/~stephend/BradsMini.jpg
Not mine, but exactly like it. (I still haven't outgrown the need for training wheels!):rolleyes:

LAWMAN 11-16-2007 10:06 AM

somebody makes a 350cc +/- 4-stroke w/ close-ratio 6-speed & e-start that weighs 230 lbs. or so & handles like my GG, I'll buy 1.

blitz11 11-16-2007 11:35 AM

Inertia
 
I am working on a vehicle guidance problem now, and thought about the Husaberg engine configuration. The real advantage just came to me.

If you think about a motorcycle, when you corner, you are rotating roughly around the rear axle if you aren't slipping the rear wheel too much (and if you are slipping the rear wheel, the yaw axis moves forward, closer to the vertical axis of the rider). By moving the crankshaft REARWARD, you really are reducing the motorcycle's inertial moment in yaw (and the effect is a function of the SQUARE of the distance from the yaw center). Less yaw inertia increases the responsiveness of the motorcycle in yaw.

In a conventional design, the crank (and its rotating mass) is considerably further ahead, which will increase the motorcycle's rotational inertia in the yaw axis when compared to the Husaberg design.

Same with the fuel. Moving the fuel closer to the yaw center of the motorcycle will reduce its inertia in yaw, allowing the motorcycle to rotate in yaw with less effort.

Because of the distance squared effect, this should have a huge effect on how it turns. I am a crappy rider, so i may not be able to take full advantage of it, but my guess is that this wouldn't be too hard to feel.

Now that I've thought about it, it seems to be a quite brilliant move. Don't think mass, think about mass distribution and inertia. Moving the crank up DOES affect inertia in roll, but if you think distance squared, the distance they've moved the crank up isn't very much compared to a conventional design. (And possibly offset by the near horizontal cylinder configuration because that mass rides, on average, lower).

It all makes sense to me now. It is certainly a good idea from a vehicle dynamics point of view. It is not a gimmick, but a well reasoned approach to high performance motorcycle design. My hat is off to Husaberg! Good work.

jeffd 11-16-2007 03:15 PM

Quote:

Originally Posted by gasgasman (Post 9999)
The live photos really show how high the crank shaft is. That's a lot of rotating mass to be carrying that high, IMO.
It's all a gimmick.:cool:

That's what I see too - if you have a spinning gyro up high - to get the bike to fall into a corner you have to move that gyro further than before... From what I see, that bike is going to like to "stand up in a corner..."

jeff

kim 11-16-2007 04:59 PM

I presume we will be able to see the real thing in the shops from mid 08, with ride reports to follow ?

Will be interesting to see what the knucklehead journo's will make of it.

K

barkeater 11-16-2007 05:09 PM

blitz,

Exactly!

I think this will be as revolutionary to dirt bike design as the mono shock was in the 70's.
http://hometown.aol.com/vintageyz/75yz250b.jpg


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