RZ350 Rear Suspension Spreadsheet

[Off Road]

I installed an FZ600 swingarm on my RZ, and started wondering how that was going to change the rear suspension on the bike.
So, I spent the winter analyzing the RZ rear suspension, and somehow managed to write 20+ pages of stuff outlining my journey.
If you missed it, and have a few days to kill, you can find it here.

http://www.rzrd500.com/phpBB3/viewtopic ... &start=750" onclick="window.open(this.href);return false;

In the end, I made a spreadsheet that shows how the rear suspension reacts, when any of the suspension components are modified.
What I found most interesting, is how small changes in any of the components, can have a significant affect on the suspension performance.
Well, on paper, the changes look significant. In the real world they probably aren't noticeable.
I thought it was all pretty interesting, and assume that some of you guys might also.

So, if anyone would like to have a copy of the spreadsheet, you can download it at this link, and then open the file in Microsoft Excel.

https://drive.google.com/file/d/0B_lMfb ... sp=sharing" onclick="window.open(this.href);return false;


Before you start playing with it, please read the following IMPORTANT information.

- Disclaimer: This spreadsheet is for "Entertainment Purposes Only".
I do not guarantee the results, and I assume no liability what so ever.
Using this spreadsheet constituents acceptance of these terms.


So, if you waste a whole bunch of time playing with it, It's Not My Fault.

- I made this spreadsheet for me, so the headings/titles may not be self evident.

- The original spreadsheet has over 50 columns of calculations. The posted version, has been condensed to show the more relevant information.

- There are 14 Variables that you can change. These are the RED numbers, on the left side of the spreadsheet.

1- Change in Relay Arm Pivot location (movement forward or backward)
2- Change in Relay Arm Pivot location (movement up or down)
3- Change in Swingarm Pivot location (movement forward or backward)
4- Change in Swingarm Pivot location (movement up or down)
5- Change in Upper Shock Mount location (movement forward or backward)
6- Change in Upper Shock Mount location (movement up or down)

7- Shock Length
8- Shock Preload
9- Shock Spring Rate
10- Relay Arm Length
11- Dogbone Length
12- Distance from Swingarm Pivot to the Upper Dogbone Pivot
13- Upper Dogbone Pivot Offset, (distance from the swingarm center line)
14- Swingarm Length
- All Variables must be entered in millimeters (mm), except Spring rate, which is in kg/mm.

From these variables, the spreadsheet calculates the following information:

1- Shock Travel (compression)
2- Swingarm Angle
3- Swingarm Height from Horizontal
4- Ride Height Increase/Decrease from stock
5- Rear Wheel Travel
6- Load on the Shock
7- Load on the Swingarm, at the rear axle
8- Mechanical Advantage of the Suspension


- The Excel file is divided into 2 spreadsheets.
Spreadsheet 1 is where I put in the Stock RZ specs.
Spreadsheet 2 is where I put in the New information.
This way, I can compare the modified suspension to the stock RZ setup.

Please note that you can Also change the Variables in Spreadsheet 1.
For instance, you could put the stock FZ600 swingarm information in Spreadsheet 1, and then make changes in Spreadsheet 2.
This would allow you to compare your modified setup, to the standard FZ600 swingarm setup.

Important: Spreadsheet 2 calculates the "Ride Height Increase", based on the information in Spreadsheet 1.
If you have RZ specs in Sheet 1, then Sheet 2 will give you the ride height increase compared to a stock RZ.
If you have FZ600 specs in Sheet 1, then Sheet 2 will give you the ride height increase compared to an FZ600 swingarm.


- When the Swingarm Angle becomes Negative (-), the Swingarm Height will become Positive (+).
This indicates that the swingarm has gone past the Horizontal position, and the Rear Axle is now higher than the Swingarm Pivot.


- The Sheets are set up to measure for every 5 mm Increment of shock travel (spring compression).
In order to get a better picture of what's happening during the first 30 mm of rear wheel travel, you can change the shock Increment to 1.1 or 1.2 mm.
The spreadsheet will then only show the first 11 or 12 mm of shock travel,
but it gives more information on rear wheel forces when when looking at Bike Sag, and Rider Sag.

Note: In order to obtain valid results, the shock travel Increments, MUST be the same in BOTH spreadsheets.


- The spreadsheet is set up to show 45 mm of shock travel, however, the oem shock will not compress that far.
Shock travel for the oem RZ shock is 40 mm. Shock travel for the Ohlins shock is 48 mm.


- And to make this Sheet useful for the "Metrically Challenged", I added a column showing the Rear Wheel Force in Pounds.



Check it out.
If you have questions, let me know.
If you have complaints, who cares. Oops, I mean let me know.

And if you've made mods to your bike, (longer shock, shorter dogbones, etc.), it would be great to get some feedback, on how the spreadsheet compares to real world modifications.
Have fun.

[kpke]

Thanks Off Road. Very nice of you to share your efforts

I will play with this when I get home from work.

[T.RexRacing]

Damn. Too bad I use a Mac.

[burleyboyz]

T.RexRacing there is a Mac version of Excel, so you can have fun with the spreadsheet too!

[mkane]

I want to sleep at night so I won't touch this.

[T.RexRacing]

T.RexRacing there is a Mac version of Excel, so you can have fun with the spreadsheet too!

You're a bad bad man.................so where can I find it?

[RuZty]

T.RexRacing there is a Mac version of Excel, so you can have fun with the spreadsheet too!

You're a bad bad man.................so where can I find it?

Probably on Pirate Bay if you don't want to pay for it, or Open Office will work, free download but I haven't tried it recently.

http://www.openoffice.org/porting/mac/

[TDR_50]

Hi Off Road, I tried to down load it but this is what I get.


This content cannot be displayed in a frame

To help protect the security of information you enter into this website, the publisher of this content does not allow it to be displayed in a frame.




Any other way to get the spreadsheet. You can also PM me if needed.

[Off Road]

Hi TDR.

I sent you a pm.

I posted the spreadsheet on Google drive, as I thought it would be the quickest and easiest way for everyone to get a copy.

If anyone else is having problems downloading the file, then send me a pm with your email address, and I'll email you a copy of the spreadsheet.

[burleyboyz]

If you open the link that OffRoad provided, it open the spreadsheet in the browser window. Go to the File tab under the spreadsheet's name and at the bottom of the list is a download option that works.

[Off Road]

Oops. I found a problem with the original version of the spreadsheet I posted.

I forgot a couple of equations, and it did not account for changes in the position of the Relay Arm Pivot.

All the other calculations are still OK, but moving the relay arm pivot, had no affect.

The error has been corrected and here's a link to Revision 2 of the spreadsheet.



https://drive.google.com/file/d/0B_lMfb ... sp=sharing" onclick="window.open(this.href);return false;