need instuctions for lowering subframe


4 replies to this topic
  • Canadianmade

Posted July 23, 2004 - 07:42 AM

#1

hello this is the first post for me im looking to lower my WR450F without touching the suspension and heard somewhere that you can lower the subframe 3/4 of an inch but there were no instructionson how to do this mod. if anyone has done this or knows how it works it would be much appreciated :thumbsup:

  • Toby_S

Posted July 25, 2004 - 04:49 AM

#2

There used to be an old post by a guy in England named Taffy called "Jack it Up" (kind of an opposite name). Look on the WR or YZ 400 forum. He cut his back tubes. It's kind of hard to follow.

I started working on one when I was "between jobs". I didn't finish it. My plan was this.
1) Cut the top tubes about 3/4" behind the front mount bolts at an angle so you can put a 1" drop at an angle of 60 degrees. (roughly parallel to the angle of the back of the tank) This clears the shock reservoir and allows the seat to slide down the tank in a straight line.
2) Cut the lower frame tubes about 3/8" down low where they impact the least mounting holes i.e. brake reservoir, chain roller. Air box mounts all stay on the top part.
3) I think you have to put an offset standoff on your airbox intake boot to get the boot to line up with the carb.
4) The pipe will be a little tricky. you can slot the ear in back but you'll have to do something up front to get the right angle. I planned on working that out once I got the welding done. Taffy rotated his header.

All the complications above partially explain why I haven't finished. I'd rather ride than tweak on my bike.

By the way, I'm 5'6". I raised my fork tubes until they almost hit the bars. Then I increased my sag by the same amount that I lowered the tubes. I got soft seat foam from Baja designs and shaved the seat 1". I rolled the edges of the seat as much as I thought was right. This works pretty good for me. I'm worried that if I do the subframe thing, I will be uncomfortable with the greater squat when changing from standing to sitting to standing all the time. Also,

Also, I'm not sure the tire will clear. I did some rough measurements with the shock spring off. It looks like I had 5/8" clearance fully bottomed with a 100/100 X 18 tire. This will probably work, maybe bottom out slightly on G outs.

-Toby

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  • yamaharichey

Posted July 26, 2004 - 06:41 AM

#3

Don't you just elongate the holes where the sub frame mounts to the lower frame 5mm ? thats supposed to lower the rear seat area about an inch.

  • Toby_S

Posted August 01, 2004 - 06:02 AM

#4

Remember, It's pivoting on the top front subframe mount. The part right above that mount isn't going anywhere.
Elongating the holes will have the greatest effect on the rear of the seat, with proportionaly less change towards the front.
Any feedback from someone who has done it?
-Toby

  • Taffy

Posted August 01, 2004 - 01:32 PM

#5

http://home.btconnec...orts/taffy.html

hope i've got the link right!

Taffy




 
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