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  #21  
Old 04-05-2005, 03:26 PM
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Default Re: lowering suspension inch to 2inch's

     

"Along the same lines, new suspension links change the behavior of the rear end since they modify the kinematics of the suspension system."

***The length of the dogbone or links only affects ride height. The "cam" is the only part of the linkage that governs the rate of the linkage.***


"....... and changing the length of the links will change the nature of the relationship between rear wheel travel and shock compression. "

***totally inaccurate****
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  #22  
Old 04-06-2005, 02:41 PM
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Default Re: lowering suspension inch to 2inch's

KINEMATICS? KINEMATICS??? MTK why are we all of a sudden talking about movies??

Years ago when Suzuki came out with the FullFloater I cut some of the connectors that went from the swing arm to the suspension arms and found that my spring rate needed changing. The suspension had gotten softer. About that time I was graced to be sent to a really cold place where I got to spend lots of time doing almost nothing but collecting pay. I had lots of time to think. I couldn't figure out why changing the length of those rods would make any difference at all. I started drawing the components,,,,started thinking of them moving in circles (something every dirttracker can identify with). started drawing them moving in complete circles,,,started seeing how they intersected when drawn to scale,,,then started moving the points that I had moved and left the shock and the rockers and swing arm pivot where they were. the axle, and the point on the swingarm were really the only things that started in a different position to the shock when all was at rest. I started moving those,,,and again thinking of each component moving not just in an arc but a full circle. Edison's invention came on inside my frost bitten gray matter. The percentage of the overlaps was changing anytime you moved the contact points. FUZZY I know,,but this is how it came to me.

Just like the amount of piston movement changes as the crank goes through a circle,,ie speeding up and slowing down at different points in the 360 degree rotation so was the axle movement depending on where the STARTING point was. If either FFR or MTK can see where I am going, please tune me up on where this fits with what you two are saying.

Bottom line to me was that the change in any of the positions of what I will call the secondary fulcrum changes the travel and has to be affecting the spring rate etc. (dang that etc is a big abbreviation).

I went through the same things with the "dogbones" that Kawasaki graced us with. I am starting to think of the links as just another way to connect your cam or rocker to the swingarm.

Now imagine a big green scraper with a bunch of welder's chalk in circles and arrows all over the side of it and moving God's tundra. It looked like some kind of grafitti done by a geometry junkie.

Anyway,,here I was out there doing Kinematics (in my own way) all the time wishing I had a movie with some women in it instead.
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  #23  
Old 04-06-2005, 04:00 PM
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Default Re: lowering suspension inch to 2inch's

Using the old KX as an example, changing the length of the vertical link(comparable to the "dogbone" on the newer bikes) will only change ride height. It has no effect(or little when taken to an extreme) on travel or rate.
If you were to change the horizontal link(comparable to the cam style link on the newer bikes) you will change the leverage ratio which will effect travel and rate. This is as easy as my simple mind can explain it lol Tdub
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  #24  
Old 04-06-2005, 05:18 PM
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Default Re: lowering suspension inch to 2inch's

Tryce, isn't this stuff your specialty, as per Eric Gorr's latest edition that you contributed to? Give us your preference for MX bike lowering.

After reading this month's MXA, they had some company that will shave the seat and lower the subframe by 5mm. Looks just like RC's '04 nationals bike. I think that is the way I am probably going to go, as it is pretty inexpensive and not too time consuming.

Do you concur Tryce?
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  #25  
Old 04-07-2005, 05:57 AM
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Default Re: lowering suspension inch to 2inch's

#1...shorten seat and/or subframe...1-2" no problem
#2...longer link...same amount of travel but lower ride height(as long as there are no clearance issues)...1-2" probable with no problem
3#...internal shock and fork mod...lowers ride height with travel limitations.
The problem with shortening the shock itself is it will bypass the initial part of the rate which is usually a little "softer". For DT this is not a problem, but for offroad or a smaller person it might end up with a "not so supple" initial part of the travel.
JMO Tdub
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  #26  
Old 04-07-2005, 09:44 AM
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Default Re: lowering suspension inch to 2inch's

Quote:
Originally Posted by FFRacing11x
#1...shorten seat and/or subframe...1-2" no problem
#2...longer link...same amount of travel but lower ride height(as long as there are no clearance issues)...1-2" probable with no problem
JMO Tdub
I agree with Tryce, allthough my preference is the longer link method because it is more versatile. You can adjust height with different link lengths and it is much easier to return the bike back to stock form than repairing or replacing the sub-frame and seat foam. This is important if you are lowering a bike until a kid grows into it. Just make sure to raise the forks in the clamps to match the drop in the rear.

I used longer links to lower my daughters KX65 2 inches, when she grows I'll put the stock ones back on. I am doing the same to my nephews KX85.

As for DCox, I think the best method is to screw a block of wood to the bottoms of his riding boots....

Last edited by Silver_Fox; 04-07-2005 at 09:51 AM.
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  #27  
Old 04-07-2005, 10:07 AM
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Default Re: lowering suspension inch to 2inch's

Quote:
Originally Posted by Silver_Fox
As for DCox, I think the best method is to screw a block of wood to the bottoms of his riding boots....
Hey! RC has demonstrated quite nicely that the motorcycle industry has this whole thing backwards. 5'6" -- 5'7" is the new standard of measure.
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  #28  
Old 04-07-2005, 10:14 AM
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Default Re: lowering suspension inch to 2inch's

Quote:
Originally Posted by DCox
Hey! RC has demonstrated quite nicely that the motorcycle industry has this whole thing backwards. 5'6" -- 5'7" is the new standard of measure.
You may be right, but the new standard of measure may be fuzzy hair, a real dark tan and the ability to do the victory sprinkler or worm.
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  #29  
Old 04-07-2005, 10:16 AM
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Default Re: lowering suspension inch to 2inch's

Only AFTER the G.O.A.T. retires, m'friend!

Quote:
Originally Posted by Silver_Fox
You may be right, but the new standard of measure may be fuzzy hair, a real dark tan and the ability to do the victory sprinkler or worm.
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