swingarm angle

Anyone know what a good starting point for swingarm angle would be on an 04/05 GSXR 750?

 

How about the effects of adding or removing swingarm angle on handling and/or traction?

 

12-15 degree's is the ballpark I remember. I'm not sure about that specific model though.

 

Speaking generally I have heard 12.5 degrees as a starting point. I have no idea about your specific bike though. The angle is measured with the suspension topped out with the tires just touching the ground.

 

Is there an easy way to measure swingarm angle in your garage without any complicated tools? Off hand I'm thinking I have a laser level, tape measure, 12 pack of Natty Light..... I should be able to do this.

How do most do it?

 

Harbor Freight sells an angle finder for pretty cheap. I am not sure how accurate it is though. A more common use for this tool is setting up satelite dishes.

 

I measured my swingarm angle by measuring the center-to-center length from the swingarm pivot to the rear axle, then the distance to the ground from from both. With these three measurements you can create a right triangle, from which it is easy to calculate the swingarm angle.

Its hard to explain, but if you draw it out on paper, you'll see that it's not too complicated.

Mine calculated out at 12.5 degrees. I've added 4mm eye-to-eye on my shock since then, but haven't recalculated yet, but obviouslly the swingarm angle is greater. It feels like the I'm getting better traction, but time will tell.

 

Is that angle with you on the bike??
I would think the angle is more important in "race/riding" mode than static.

 

The angle is measured with the suspension fully extended (e.g. pegs on jack stands).

 

I agree. This removes spring rate variables to will influence the swingarm angle on the track.

 

""The angle is measured with the suspension fully extended (e.g. pegs on jack stands).""




I guess that you could then, calculate the spring rate at different moments of inertia and graph out what the swingarm angle would be, add to this the riders weight in riding gear, along with that extrapolation you could generate a chart of numbers that were pleasant to the taste of the rider.....

 

I'll just have to trust you on this...

For my purposes, I was simply looking for a baseline to work from. I need to measure it again after making the changes that one of our local suspension gurus suggested as it's hard to estimate the %change in swingarm angle when both the front and rear ride height have been changed -- we added 3mm of height in the front and 4mm in the rear.

 

That's the problem with the world today, EVERYONE'S the next Maxx.

 

No actually not EVERYONE...
I have watched Max's DVD though and did learn alot, also learned alot from Mike, as he has been working with Matt for almost 4 years now.
Also you have to pick up on the humor of how I phrased the reply..sorry but I am after all a SmartAss.

 

Didn't see the humor there huh?

Sorry Mr. Lynn, no harm meant.

 

None taken,
Mongo you are a LARGE YOU...BBQ??

Where IS Max when ya need him?

 

http://forums.13x.com/showthread.php?t=110617

This is what I was thinking of as I was typing.

I'm betting not many people call you Mr. Lynn though.

You know, I'm just about as funny as a heart attack.

 

I know what you refering to.. I am old not dead.

I was making a funny about the "Sweet #'s".... Get it, "extrapolation you could generate a chart of numbers that were pleasant to the taste of the rider"...