2006 Yz450f

[machoman_#618]

Butta, I say it changes with each rider. How hard is it to push over a tree from the bottom of the trunk? verses pushing it over from the top. weighs the same. 14 inches was just a guess ,true. Is the weight of a standing rider weighing 220 pounds on the pegs, got the same center of gravity of a rider weighing 160 pounds?

[Yamaha35]

Not to break up your CG conversation but didn't Yamaha delay the thumper frames because of the oil in the frames? Maybe this takes more time to design while a 2 stroke frame doesn't need this feature.

Back on the CG issue, all mags have said that the YZ's feel very light with the new frames which means Yamaha didn't proportionally do things wrong.

[myoung]

Not to break up your CG conversation but didn't Yamaha delay the thumper frames because of the oil in the frames? Maybe this takes more time to design while a 2 stroke frame doesn't need this feature.

Back on the CG issue, all mags have said that the YZ's feel very light with the new frames which means Yamaha didn't proportionally do things wrong.

Yes, they do feel lighter, no doubt about it, stiffer too I might add. I've ridden an aluminum frame YZ250 and was very impressed by how nimble it was, not very impressed in whoops though. However, that does not answer the question of wether or not Yamaha could lower the CG on it by changing frame materials. Of course, now that I think about it, the CG on the 2 smokes was never really something I've heard people complaining about so I don't imagine it would have been a priority for Yammy. I can tell you this though, people will be looking for it on an aluminum frame 450.

[Yamaha35]

AMA rule is 450cc limit for 4strokes. A 472 would be suicide for Yamaha and overkill. Its fast enuff.

Electric start will be on the WR450.

[Ga426owner]

Not to break up your CG conversation but didn't Yamaha delay the thumper frames because of the oil in the frames? Maybe this takes more time to design while a 2 stroke frame doesn't need this feature.

Back on the CG issue, all mags have said that the YZ's feel very light with the new frames which means Yamaha didn't proportionally do things wrong.

I do not think Yamaha had any intention of releasing Alum frame in 250F or 450F in 2005........ ?

[machoman_#618]

Most of my information is from the machinery’s handbook

Center of Gravity-The center of gravity of a body, volume, area, or line is that point at which if the body, volume, area, or line were suspended it would be perfectly balanced in all directions. For symmetrical bodies of uniform material it is at the geometric center. The center of gravity of a uniform round rod, for example, is at the center of its diameter halfway along its length; the center of gravity of a sphere is at the center of the sphere. For solids, areas, and arcs that are not symmetrical, the determination of the center of gravity may be made experimentally or may be calculated by the use of formulas.

My thoughts on this are, with a bike we must fine the center of gravity on different parts of the bike and use those points as an axis point to fine others. Basically I’m thinking the foot pegs must be the key point of center of gravity. This is because this is where the most weight is located with a rider operating the motorcycle.

I do believe the alum frame will only provide less weight. Same motor with less weight equals more power.

These are only my thoughts not fact, I like learning also.

[dunn2500]

they better the suzuki is on its way and kawi not far behind they have had the most time to develop this bike theres no reason it should'nt be right there with the rest of them i can almost guarantee they will have an aluminum frame next year if they dont they will have to sell them for 5000 otd and get rid of that blue plastic go back to yellow or the white and red they had in the 80's

[myoung]

The only info I have about finding a CG of a vehicle is in a book that has automotive math. I wasn't sure if it would be the same as finding CG on a bike though, so I did a little looking around and from what I can tell they do figure out vertical CG the same. The short and sweet is, you weigh both ends on flat ground, then lift one end and weigh the unlifted end, then enter weight measurements and lift measurements into the necessary formula and Viola, vertical CG. This is where I was starting to get a little confused about what effect higher mass(like say, hypothetically, a really heavy fuel tank on a bike) versus lower mass(a bike with a feather light gas tank) would have on the weight measurement of the unlifted end. Unless I was to do my own experiments with looking for CG on a bike and adding or subtracting weight in different locations to see what effect it would have, it's hard for me to just visualize where the CG would be on any given bike. I can only just think of things logically and assume what is possible.

[Butta]

Most of my information is from the machinery’s handbook

Center of Gravity-The center of gravity of a body, volume, area, or line is that point at which if the body, volume, area, or line were suspended it would be perfectly balanced in all directions. For symmetrical bodies of uniform material it is at the geometric center. The center of gravity of a uniform round rod, for example, is at the center of its diameter halfway along its length; the center of gravity of a sphere is at the center of the sphere. For solids, areas, and arcs that are not symmetrical, the determination of the center of gravity may be made experimentally or may be calculated by the use of formulas.

My thoughts on this are, with a bike we must fine the center of gravity on different parts of the bike and use those points as an axis point to fine others. Basically I’m thinking the foot pegs must be the key point of center of gravity. This is because this is where the most weight is located with a rider operating the motorcycle.

I do believe the alum frame will only provide less weight. Same motor with less weight equals more power.

These are only my thoughts not fact, I like learning also.

I misunderstood...I thought you were speaking of a bike only, not the rider. Throwing a rider onboard with the entire weight on the pegs changes things....however, without a rider onboard, I would guess that the CG is located toward the rear of the motor, up above and forward of the swingarm pivot point.

Interesting thought, though, and it would make sense that the engineers would design the bike with the rider included....hence the stock suspension settings for a 150# rider..... oh, what a job!! ?

[Todd98YZ400F]

I have heard that they will come with a frame made of wood.. ???

Hell yeah, You could mod the heck out of that frame with a pocket knife. ?

[Heckler]

A 4 stroke will always have a higher CG than a 2 stroke. The head alone on the thumper will raise the CG with all the extra weight. The Honda does clearly have a lower CG due to the frame design, not the material, more of the bikes weight is carried lower thus lowering the CG. I can really feel the difference, my YZ450 is lighter than my CRF250x but the X feels lighter, if you take the bike while standing next to it and lean it over the point in which you really start to feel the weight it will be sooner on the YZ because the CG is higher. The CG also moves around as you ride, hit the brakes it moves forward, hit the throttle it moves back. It's also different for a 6'2 rider or a 5'6 rider.

I also would like to see the CG lowered on the Yami, the seat height should be lowered also, they just did it with the 05 WR and it feels better but not there yet.

[condog_aus]

Its funny that you blokes are in hear discussing the C of G the same as us in the MX Tech forum. But do you think that some blokes get get it throught thier thick heads that this is why weighting the foot pegs, and outside peg when cornering is so important. Why pay thousands of dollars to buy bikes with formula 1 level performance on dirt and then turn it into a pickup truck by placin all your rider weight on the bars and seat. You are so right about the difference in C of G between the Yamaha and the Honda.

You know an interesting specification on all new bikes and bike tests would be to lay the bikes over 27.5 degrees then to 45 degrees on side and measure the weight at the bar end or side of the saddle. As this would really make a few bie manufaturers sit up and take note of some top heavy issues.

[Satch0922]

One thing to think of guys. IF the 06 is aluminum , it will be VERY popular. That means no deals from the dealer, a wait to get one etc etc. I think that 06 will be a tough year for the 450 no matter what. If it's steel everyone will be bummed, if it's aluminum prepare to wait and to pay $$$$$$$$$$.

JMHO

[machoman_#618]

ahhhh! my bud, you have gave me a hint!!!!

[John_Lorenz]

Ya but we blots need to know if you wieght the outside peg do you think it will be with aluminum ?

Its funny that you blokes are in hear discussing the C of G the same as us in the MX Tech forum. But do you think that some blokes get get it throught thier thick heads that this is why weighting the foot pegs, and outside peg when cornering is so important. Why pay thousands of dollars to buy bikes with formula 1 level performance on dirt and then turn it into a pickup truck by placin all your rider weight on the bars and seat. You are so right about the difference in C of G between the Yamaha and the Honda.

You know an interesting specification on all new bikes and bike tests would be to lay the bikes over 27.5 degrees then to 45 degrees on side and measure the weight at the bar end or side of the saddle. As this would really make a few bie manufaturers sit up and take note of some top heavy issues.

[Satch0922]

ahhhh! my bud, you have gave me a hint!!!!

LOL Macho.......here is another hint....the bike is blue. ?

[ThumperKid250F]

Ya but we blots need to know if you wieght the outside peg do you think it will be with aluminum ?

God i sure hope so ?

[condog_aus]

Im just watching the movie flubber with the kids now a flubber frame would be real cool.

[Beef]

Naw, we still need a ridgid frame. Now flubber TUBES would be cool! You could dinomite some jumps with THAT! ?

[Dan_Lorenze]

I would just about bet the farm on the aluminum frame for 06. I've heard rumors about the gearbox but I'm almost positive that the 06 YZFs will be a new bike with a frame similar to the YZ250s.