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blackout

My Rear Suspension Mods

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blackout
[div style=text-align:justify]I added a Nitron R3 shock a few weeks ago and like it a lot.
 
0806161718b_zpskvtg85j8.jpg
 
Below is a link I made to raise the rear of the bike.  It is adjustable in small increments.  I have not installed it yet, but hope to this weekend.  It uses a QA1 aluminum rod end on the frame side.  I'm pretty sure it will work, but I won't know for sure until I try it this weekend.
 
 
0824162029_zpsdlomodvx.jpg[/div]
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Mr.Puss
What will keep it from rotating?
The shock. 
 
 
 

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blackout
It replaces the link that connects to the frame and bell crank. This is the link that dictates ride height. This link will attach to the frame a little different than stock.

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blackout
I started out with a 675 lb/in spring, but could only get 1.125" of sag before running out of threads on the shock body. My goal was 1.5" of sag. I decided to go down to 625 lb/in to give a softer ride and allow more sag adjustment. This did the trick, I'm close to 1.5" now. BTW, I weigh 180 pounds with gear. A shorter spring would have worked as well, but a shorter spring has less compression travel so that would need to be looked into. Removing and installing the spring proved to be a challenge until I machined a hole in a piece of 3/8" thick aluminum just larger than the spring hat. This made it easy to compress the spring with a shop press to create the clearance needed to remove the spring hat.
 
0815161512_zpslup4vbph.jpg
 

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twf
It replaces the link that connects to the frame and bell crank. This is the link that dictates ride height. This link will attach to the frame a little different than stock.
Dog bones. Are you just cutting those shorter and drilling hole for your piece? 
 

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blackout
It replaces the link that connects to the frame and bell crank. This is the link that dictates ride height. This link will attach to the frame a little different than stock.
Dog bones. Are you just cutting those shorter and drilling hole for your piece? 

 
 
No, complete replacement of the dog bones.

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Guest ChicagoAJ
What will keep it from rotating?
The shock.
BUT WHAT WILL KEEP THE SHOCK FROM ROTATING?!
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twf
The shock.
BUT WHAT WILL KEEP THE SHOCK FROM ROTATING?!
He is replacing dog bones with it. I still like to see how it will be attached to frame. I am picturing extra hinge right now just looking at it. 

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Mr.Puss
The shock.
BUT WHAT WILL KEEP THE SHOCK FROM ROTATING?!
The bolt.  :D 

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twotone
BUT WHAT WILL KEEP THE SHOCK FROM ROTATING?!
The bolt.  :D
 
But, what will keep the bolt from rotating?

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i28
The bolt.  :D
But, what will keep the bolt from rotating?
 
The Loctite. Obviously :D

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hordboy
Nice piece and idea.  I don't see what the worries are about, just a couple bushings needed at the lower end to make it fit the frame connection.  I'd like to see what could be done with the linkage ratio with adjustments to the new part, and the shock.
 

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blackout
Nice piece and idea.  I don't see what the worries are about, just a couple bushings needed at the lower end to make it fit the frame connection.  I'd like to see what could be done with the linkage ratio with adjustments to the new part, and the shock.
Thanks.  
 
Yup, I have a length of aluminum tube for spacers to go on each side of the rod-end.  I won't know the length needed until I pull the stock parts off.
 
I tried designing a double adjustable part, using LH and RH threads, that could be shortened without removing any bolts, but the link length is too short.
 
You make a good point about the linkage ratio.  Too me, a longer shock pivots the linkage too far rearward, so changing the dog bone link length seems like the better option to raising the rear of the bike, but that's just a guess.
 
While I am new to bike suspension, I have experience with race car suspension.  Below is a frame and suspension that I built and designed from scratch.  It's an E Mod Shelby Cobra Replica that I autocrossed for many years.  It is quite fast when I let a good driver race it.  LOL
 
 
vpmframe1.jpg
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hordboy
Andy @ AP Moto says his short link takes the "knee" out of the stock linkage curve, but I have not tried it, nor do I have a good way to accurately measure stuff.  It's an area worth exploring.
 

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pgeldz
Andy @ AP Moto says his short link takes the "knee" out of the stock linkage curve, but I have not tried it, nor do I have a good way to accurately measure stuff.  It's an area worth exploring.
I just installed it last week, and gonna test it out this weekend at the first track day of the season (for us).  I'm no racer though...so don't expect Rossi levels of feedback on this item, lol. 
Stock linkage curve aside, I do know that it raises the rear a fair bit, and when I went to the taller 60 series tire I got faster, and the bike was more stable through quick transitions, especially over elevation changes.
 
Andy said his FZ-07R's have the 60 series tire, his link, and rear shock at 318mm eye to eye.
 
When I did the 60 series rear tire, my shock was at 314mm eye to eye, so even with his link I'm still not quite as tall as his bikes in the rear, and I noticed a difference just going to the 60 series rear.
 
Can't wait to test the whole combo this weekend.
 
I'll let you know how it goes...
 
:)
 
- Paulie
 
 
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hordboy
If you have stock forks/triples, I hope you have a steering damper. ;)

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twf
When I measured linkage I found it to be linear.
We are using stock link and longer shock on our race bike.
We also used 180/55 and 180/60 Pirelli tires.
 
IMG_1715_zpsytz9obbz.jpg
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pgeldz
If you have stock forks/triples, I hope you have a steering damper. ;)
I'm not using a steering damper... 
Triples are stock, but the forks have Traxxion Dynamics AK20 cartridges in them.  I have a Penske Triple Clicker Remote Reservoir 8987 in the rear...
 
I asked Andy if his link was only for use with his R6 front end conversion because I know that conversion changes the geometry a little because of the custom triple clamp, and he said the link would work fine stock geometry forks.  
 
I guess I'll find out tomorrow  :)
 
- Paulie
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blackout
Good tech, thanks guys!
 
The taller rear tire raises the rear, reducing rake and trail, but does it without increasing rear anti-squat. So that change would have a little different affect than raising the rear with the suspension linkage. I guess something to think about...

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hordboy
It's an area I have not explored in detail yet, I'm just going on what AP said. I did some crude measurements early on and came up some something... not linear. Zoran, did you measure starting from stock length at 310, or something else? FWIW I run my shock at 314mm and -5mm on the front. Stock link. It gets skittish at higher speeds... needs more trail. But I'm an old Ducati racer too, everything feels skittish. ;)

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twf
180/60 is taller in middle but once leaned it is same as 180/55, that is for Pirelli. We measured this because in general we don't like 180/60 on sv's.
JD, measured with stock shock (you can see stock shock with no spring on that picture) all the way through the travel.
We are way taller than you, both ends.

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blackout
I needed to remove the foot peg plates on both sides to access the lower pivot bolt.  These bolts were red lock-tighted at the factory.  I cleaned the threads with a 10mm x 1.25 tap and die to assure reassembly without cross threading.
 
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0828161519a_zpsgqhgszmg.jpg
 

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blackout
The left plate only needed to be pulled out a couple of inches and then pivoted back and up out of the way.  That way I never needed to remove the swingarm frame pivot bolt.
 
 
0828161519_zps9pxfjlv2.jpg

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