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Question: 2012+ WR frame?

8 posts in this topic

Why is the 2012+ WR450 in a YZ 250 Frame? Why not a 450 frame? Is it just for lightness or nimbleness?

Thoughts on subject please.

Thanks

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First off, there is no more YZ450 frame for a conventionally layed out motor anymore.

The new YZ450 frame has the reverse motor.

Secondly, it is not 'the YZ250 frame'.

It's BASED on the 250 frame, using some of it's spars and castings.

It is not the same frame.

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Huh, I had read that it was the exact same frame with the exception of motor mounts. I can pull the article if folks would like to see it.

Also, I guess I can try to simplify my request or at least the premis: Krannie's observation about the the current YZ450 engine makes good sence, but I guess barring that difference why might a coorporation choose to go with the 250 frame rather thatn the 450.

My thoughts would be for weight savings and feel. Also the fact that the WR450 typically is not putting the same forces of stress that the YZ450 frame is engineered for.

A secondary question here: Can anyone compare the YZ 2010-2013 throttle responce (big powerful hit / injection ) to that of the 2012-13 WR?

thanks

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I can tell u first hand that compared to a 09 yz450 to me my full exhaust , remapped wr hits harder and has more power. Or ar least it feels like it. My buddy owns the yz. But his is getting old so maybe when new things would have been different. I would love to ride a new yz 450 to find out. But honestly my bike already has more power than i will ever use. I can wheelie the bike in all gears. 1-3 with just a quick throttle, 4th with throttle and a tug. 5th using clutch it will wheelie easy. I am amazed every time i ride it.

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Yep, it is in fact a YZ250F frame with different engine mounts and an extra lug or two cast into the frame to facilitae the sub-frame.

The reason Yamaha chose to go this route is everyone raved about the YZ250F handling so they figured let's shoe-horn the WR450 motor in there to create the ultimate off-road hot rod. They've pretty much suceeded. The bike is quick but that is more down to the injection than the frame...same motor as the 2007-2011 WR450F.

The handling feels lighter due to mass centralization although the bike weighs exactly the same as the previous generation. I've noticed the 2012 is not as stable as my 09....not a big deal as you just twist the throttle harder and lift the front....no more stability issues ;-).

The only real problem I have with the bike so far is it is quite cramped in the rider ergo department. I'm 6'2" and I've installed GYT-R handle bar mounts (10mm up and 5mm forward), KX-Hi bar and Fasway pegs in the low-boy position and the bike is still cramped. Obviousy a direct result of starting from the 250. Looking for more ways to open it up a bit. If anyone has any ideas I'm all ears!

Other than that I'm pretty happy with the bike. Just orderd Dave Simon's intake cam so we'll see if it's all he claims it to be (I hope it is). 5hp in the middle and up sounds pretty damn good. Hate to lose the bottom hit in the process but he assures me it doesn't affect it too much. Will let you all know how it works when I get it installed.

John

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In either an article I read or a video I watched another reason mentioned for not basing the WR on the latest YZ450f is limitations in fuel capacity.

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In either an article I read or a video I watched another reason mentioned for not basing the WR on the latest YZ450f is limitations in fuel capacity.

No doubt that was one of Yamaha 's concern's, fuel range.

As it is, the fuel range is on the short side for anyone that doesn't live on the East Coast.

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