MXP1MP

Member
Nov 14, 2000
1,845
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check out this link, not a good pic but you can see it's the aluminum frame yamaha has been testing with the YZ250. Pic quality isn't that good, but it looks like the cylinder and ingition are different too.

http://www.cyclenews.com/ShowStory.asp?HeadlineID=5531
 

Sayntmatt

Member
Jul 22, 2002
148
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mmmm not sure about the frame it looks like the normal one to me?? Agreed though the cylinder and ignition do look different! The ally frame that they used on the 250 looked fatter than that. Have Yam ever tried an ally twin spar frame like the Hondas and now the Zooks??
 

dirt bike dave

Sponsoring Member
May 3, 2000
5,349
3
Originally posted by Sayntmatt
Have Yam ever tried an ally twin spar frame like the Hondas and now the Zooks??

 

http://images.google.com/imgres?imgurl=www.eric-gorr.com/images/yzm-81.jpg&imgrefurl=http://www.eric-gorr.com/twostktech/ad_2tunvd.html&h=189&w=269&prev=/images%3Fq%3Dyzm%2Bphoto%26svnum%3D10%26hl%3Den%26lr%3D%26ie%3DUTF-8%26oe%3DUTF-8%26sa%3DN

Tried to find out more about this twin spar Yamaha, but I think it was a works bike.  Looks just like a Honda.

BTW, Yamaha reportedly ran an aluminum frame on Bartolini's YZ426 a year or so ago, but it looked like the standard frame.
 
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Camstyn

LIFETIME SPONSOR
Oct 3, 1999
2,247
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That was a cool bike!!!

1987yzm500.jpg
 

MxKid512

Member
Feb 10, 2001
141
0
FWIW, Everts ran the works 426 with the aluminum frame the past few years. When the 450 came out, they kept the stock steel frame. Everts liked the stocker way better than his works alloy frame (to rigid)
 

Sayntmatt

Member
Jul 22, 2002
148
0
My appologies MXP1MP, it seems your source was right about that yam having an ally frame.

Here is another link to it........
http://www.dirtrider.com/rmz450debut/#
 

MXP1MP

Member
Nov 14, 2000
1,845
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That's a better pic, it looks different than the one they was running on the yz250 last year there's an absense of the cast holes. But parts of it still look casted and the headtube looks like a kawie's. The motor from the right show's the new cases too, I like how the clutch pull has gone inside the case plus the pipe sure is different. I suspect it's just a test bed bike, but who knows for certain.
 

baxterj787

Member
Oct 4, 2001
36
0
That twin spar YZ frame was a Japan only project from 1991-1992. From what I remember, the bike also had a...unique... head design that was somehow filled with nitrogen, giving the engine a variable compression ratio.

I was surprised to see how similar the 97-99 Hondas were in appearance. Too bad the Yamaha version was shelved.

The old YZMs were different animals. Water-cooled, power-valved, aluminum frame, VERY trick subframe/airbox combo, etc... Again, what could have been.
 

whitesands26

Mod Ban
Nov 17, 2002
220
0
Yup...Yamaha is most likely going aluminum....Looks like all those proud Yamaha owners that like to blab about the steel verses aluminum issue and like to bad mouth Honda are going to get a nice helping of humble pie when they discover Yamaha was actually WAAAAYYY BEHIND in the development curve and now are playing follow the leader (Honda) just like suzuki will be doing...

Bad part for yamaha...Honda has much....MUCH more experience building aluminum framed MX bikes and it appears as though Yamaha will go through some difficult times trying to get it right....

Funny thing is the new Suzuki 4 stroke looks like a Yellow Honda...lol
 

Coop37

Member
Oct 4, 2000
317
0
The aluminum frame that Yamaha makes we be far more advanced than Honda will ever be able to make because Yamaha has a patent on a new form of aluminum casting which removes almost all the air bubbles is the casting process, there for the casting can be made much thinner and stronger. We have already seen this cast process on the swingarms of the new yz's.
The frame that Honda is building is heavier than the metal frame on the yz450? so Yamaha knows that the only way to make it lighter than metal is to use this new process. so the frame that Yamaha builds will be way different than Honda's, most likely the frame will act much like the metal frames now on the Yamaha's, that are far superior to the Honda aluminum frames.
 

bedell99

~SPONSOR~
May 3, 2000
788
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Don't speak so soon Coop37. If you follow street bikes, you would know that Honda is also using the same casting techniques. I think this benefits all of us and do believe that one day "most" of out motorcrossers will be aluminum framed. I also think that this give us more options. I believe yamaha can learn from honda on the frames, just as honda learned from yamaha on there 4 strokes. Aluminum is an inherently more stiffer/brittle than steel, but with these new casting techniques employed by both honda and yamaha I feel they will figure it out how to employ the right amount of flex in there frames. Here are 2 links that explain how yamaha and honda are using this process. I can't wait to see what our children will have in 10 years to ride.

Yamaha:
http://www.motorcycledaily.com/11march02yamahastechnique.html

Honda: (Scroll down a bit)
http://www.honda.co.uk/motorcycles/mc2003/cbr600rr/chassis.html

Erik
 
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