[Chatman128]

There's currently a thread on setting the rear suspension in the Burgman 400 (2007+ model) forum. All the posters seem to describe significant differences in the feel of the suspension based on which position you have the shock collar set to.

I was under the impression that the 'feel' of a suspension was a result of the interaction of a bunch of variables: geometry, spring rate, compression damping and rebound damping come to mind. Changing the shock collar setting doesn't affect any of these (except possibly geometry slightly). I thought you adjusted the shock collar to get yourself in the general 'middle', perhaps somewhat 'above' middle, of the suspension travel so that you don't bottom or top out. But as for plushness, it is what it is. To change it you need to change your spring rate or the damping characteristics or both. Am I missing something?

 

[JohnK]

When you adjust the shocks on the Burgmans you are changing the preload setting which in effect does change your rate and damping traits.

 

[Mike337]

It needs a nicer shock with comp and rebound adjustments.

 

[Quantum Mechanic]

Chatman, John's right. When you alter the preload it changes the suspension dynamics in almost every respect to a greater or lesser extent. But obviously, with just preload adjustment, you cannot fine tune every aspect like you can on some bikes. However, if you play with the preload settings you will be pleasantly surprised at how you can make the bike feel. The Burgman 400 is a gem in it's simplicity and yet sophisticated in how it performs!

 

[Desert Rat]

When all the tech stuff is set aside the only thing that matters is what setting is right for you. Just play with the setting & go with the one you like best.

 

[Scootereno]

+1
I tried every setting over the first 3 months of ownership until I found what's best for me. As stated it is what it is with a limited range of presets. Find your comfort level and go with it.

 

[DandyDoug]

IMHO the single best dollars you can spend on a motorbike of any type is to improve the stock suspension.
Some people are happy with the OEM units and play around with them , but are really doing little to improve on a cheap compromise .

If you ever get the chance to see how a decent shock is made compared to any OEM unit you will immediately see the difference.

 

[Chatman128]

When you adjust the shocks on the Burgmans you are changing the preload setting which in effect does change your rate and damping traits.

I have a feeling that if you were to measure, somehow, the length of the spring with the bike on its wheels, I think you would find it to be same, regardless of the setting. You are simply changing the ride height, e.g. how much sag is required to get the desired quiescent spring force. You may have changed the spring rate but you also changed the spring length. The overall result is nada.

 

[Jeff_MdR]

Chatman - are you saying that when a rider claims that at '4' the suspension transmits more shock and vibration that it bothers his back, but at '2' he can ride comfortably for hours, is imagining these differences?? If not, what do you mean by the "overall result is nada"?

 

[Chatman128]

I'm saying that I found essentially no difference in any of the settings when I tried them other than I tended to bottom out at 1. Perhaps the difference is subtle and beyond my ability to discern.

As a practical matter, I was trying to understand why there should be any difference at all other than sag. I still don't understand it. When you go to sport bike forums, they talk about adjusting various dampings and refer to 'preload' only for setting ride height. The shock you feel traveling over a bump should be related to compression damping and the spring rate at that instant. As far as I can tell, the spring rate at that instant is fixed by the load (bike weight and rider weight) on that tire.

I have noticed a tremendous difference in the quality of ride with pretty small adjustments to seating position.

 

[Jeff_MdR]

Here's how I "understand' it in my English major brain (I may have the science of it completely wrong and may be misunderstanding entirely how suspensions work).

I think it has to do with inertial force (a bump in the road at one end and the load [rider] at the other) and the progressivity of the spring. Let's say setting #1 is an uncompressed spring and it will respond (begin to compress) to a force of 1 pound. Setting #2 slightly compresses the spring, it 'stiffens' it because now it needs 2 pounds of force before it begins to compress. If the load remains the same, what happens at #2 when only 1 pound of force is applied? It's dissipated via shock or vibration which may be absorbed by the seat cushion (or cushion + my butt, or cushion + butt + spine).

Fortunately, it doesn't matter too much if my brain doesn't understand it, because I leave it to my ass and my back to make the final decision.

 

[Buffalo]

I'm saying that I found essentially no difference in any of the settings when I tried them other than I tended to bottom out at 1. Perhaps the difference is subtle and beyond my ability to discern.

Same for me. I don't feel any difference in quality of ride. I run mine on 5 all the time because it provides a little more ground clearance when cornering. YMMV

 

[Just Me]

Same for me. I don't feel any difference in quality of ride. I run mine on 5 all the time because it provides a little more ground clearance when cornering. YMMV

+1!

 

[v8eyedoc]

Never changed mine from the factory setting and have no idea what that is but I am happy with the ride..........So I didn't play with it.

 

[Buffalo]

One point on what it does. With the bike on the ground and it's weight on the shocks the shocks are not at their maximum extension. When you adjust up to a higher level it's going to push up on the spring which will cause the shock to extend out more. The spring will not be any more compressed than it was unless the shock has reached maximum extension. Therefore the ride will not be any more harsh. You will however lose some of the shocks ability to extend before it hits the stops at maximum extension. However you will gain travel before the shock reaches the stops at maximum compression.

 

[itlives]

After reading this thread, I set mine to "2", (it was on "3"). It may be my imagination, but I could have sworn the ride home was smoother.

 

[Mike337]

A bike should bottom on a harder hit once in a while, otherwise you're not using all its travel. Mine will bottom once or twice a day maybe, but at least I can feel it go up and down over bumps and not just hit and bounce over them.

 

[Chatman128]

I checked mine this weekend and I've been riding with the setting at 7. I changed it to 2 and once again didn't notice a difference (but I did scrape the stand with 115 lbs. of animal food strapped on the back). So I figured it was a subtle difference.

Then I came upon a method to evaluate the more subtle aspects of the ride. I take a banana with my lunch every day to work. Usually, it's a little banged up when I arrive, and indication of the degree of disturbance in the underseat storage area. Well, when I got to work this morning, it was nearly pristine. I think it might have to do with the degree of compliance over smaller bumps. It does seem to be less affected by washboard type road surfaces. There is still not much difference over large irregularities, speeds bumps and such.

I suppose that if you have spine issues and are perhaps at a threshold as to whether you can comfortably ride or not, it may make the crucial difference. The banana doesn't lie.

 

[Jeff_MdR]

At the confluence of Science and Fruit we have Sir Isaac Newton and his apple, and now Chatman128 and his banana. We'll done , sir!

 

[Jeff_MdR]

Why have preload adjusters at all?? Here's why:

(from a good preload explanation at http://fixbroke.tumblr.com/post/39188918110/spring-preload-and-sag-what-does-it-really-do