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What kind of steel is an 03-05 YZ450 frame made of?

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On 4/18/2017 at 7:33 AM, grayracer513 said:

It was advertised as chrome-moly, and was said to have been 5 pounds lighter than the '02 YZ426F frame.

Do you know if they did it on any other models as early as 2003?

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thank you very much grayracer. I ask this cause I'm stretching a yz frame to fit a ninja 650r for a dual sport project I'm making.

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thank you very much grayracer. I ask this cause I'm stretching a yz frame to fit a ninja 650r for a dual sport project I'm making.

Yeah, we're gonna need pictures of this project.

 

You can't be dropping teasers like that in here with no pics.

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11 hours ago, TN Dirt Rider said:

Yeah, we're gonna need pictures of this project.

 

You can't be dropping teasers like that in here with no pics.

Lol so far it's just parts, waiting on the chromoly tubing and swing arm but once I get the motor aligned and in the frame I'll post the progress.

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I came the conclusion before welding the frame that this is just a steel frame, there are seams inside the tubes where chromoly does not.  So if anyone else is interested on knowing whether a 03-05 steel frame yz450 is chromoly or steel, it's steel. lol this is great cause I don't wanna deal with chromoly.

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15 minutes ago, grayracer513 said:

The presence of seams does not preclude chrome-moly steel.  Look into spark testing. 

http://www.weldersuniverse.com/metals_steels.html

I looked into spark testing, but couldn't really tell. But I read this off a 2003 YZ article

Quote

Never used before in the manufacture of a motorcycle frame, this immensely durable super high-tensile steel is around 25% stronger than chromemolybdenum steel alloy, and its use has been made possible by a special hardening process that is exclusive to Yamaha.

Yamaha coded this steel as YSC980Y, and I have no idea wtf that is. 980X tube?

Edited by meanbean

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Well, there's something a little more authoritative, isn't it?  I do recall their web site stated the then new frame was 6 pounds lighter than the '02 frame.  In fact, it accounted for the bulk of the weight difference.

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15 minutes ago, grayracer513 said:

Well, there's something a little more authoritative, isn't it?  I do recall their web site stated the then new frame was 6 pounds lighter than the '02 frame.  In fact, it accounted for the bulk of the weight difference.

I just can't believe how hard it is to find information on this. I should just mig it using regular mild steel tube and say F it, I mean it seems like yamaha made some break through in by making their own type of steel then 3 years go to alumnum. lol

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The frame was MIG'ed at the factory, but I don't know whether it underwent any sort of post-build heat or other treatment.  I am not a certified welder, but my stuff seems to stay together pretty well.  I would probably MIG the thing, gusset the joints, and relieve it afterward, but you might want someone else's advice on that question.

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Sounds like a bitchin" project.  I'm not a certified welder, but have been doing my own custom fabrication for about 12 years.  A lot of street rod stuff, and also have built a few drift trikes.  I'd probably just do MIG with mild DOM, mild wire, and gussets like Grayracer mentioned.  Something like this:

(by no means proportionate, just whipped it up quick on paint.)

gussets.jpg

Edited by High On Octane

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5 hours ago, High On Octane said:

Sounds like a bitchin" project.  I'm not a certified welder, but have been doing my own custom fabrication for about 12 years.  A lot of street rod stuff, and also have built a few drift trikes.  I'd probably just do MIG with mild DOM, mild wire, and gussets like Grayracer mentioned.  Something like this:

(by no means proportionate, just whipped it up quick on paint.)

gussets.jpg

Thanks man! I think I'm just going to go the route I should've went all along and do what you guys recommend. I went to school for welding and sketch myself out at times with the welding combos that is needed for "perfection" however I seen many times over and over alot of it is really not necessary especially on a project like this. Seen many rigs hold up fine with basic procedures. I get too caught up in my thoughts sometimes lol.

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6 hours ago, meanbean said:

Thanks man! I think I'm just going to go the route I should've went all along and do what you guys recommend. I went to school for welding and sketch myself out at times with the welding combos that is needed for "perfection" however I seen many times over and over alot of it is really not necessary especially on a project like this. Seen many rigs hold up fine with basic procedures. I get too caught up in my thoughts sometimes lol.

Just because this projects sounds cool AF, I looked up a bare frame.  If I was doing this, this is how I'd approach it.  .1875 wall DOM same OD as the factory tubing, and find a smaller tube that will fit inside the new tube and stock frame tubing.  Drill about 5/16" holes thru the frame and new tubes near the joints.  Cut six 4-6" sections of the smaller tube and place half of it inside the ends of the new sections of tube and do plug welds over your drilled holes.  It will help strengthen the joint and help keep things lined up when you butt weld the new section to the frame.   Of course it may or may not be feasible once you get into it, but it's where I'd start.  Keep it simple, but keep it strong.  I'm definitely going to be following this thread.  :thumbsup:

YZframe.jpg

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Actually, as I look at that closer.  Maybe cut the whole section where the top tube and middle tube meet, before the lower hoops go down, instead.  That way you can keep all the rear geometry for the suspension.  I think you could use the original suspension and swing arm that way.

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