GS 1000 Rear shock mounting location

[48woody]

Hello;

Was there any real advantage to moving the top rear shock mounting location , forward to give a greater angle. Similar to this bike for sale on Fleabay.

Item 300449739006

 

[salty_monk]

None that I can see...

It would allow for use of a longer shock but would make the stroke less efficient I would think with a much larger bending moment through the shaft of the shock.

I'm ready to stand corrected though

 

[tkent02]

You get more wheel travel for a given amount of shock travel.

 

[GEE-S]

Not sure if it looks good although I do know it won?t work as well?

Hard to explain, there is directional force and suspension works directly apposing it.
In other words if the swing arm moved up and down in a straight motion not the arc that it does, then the shocks would have100% efficiency mounted in a vertical fashion to the swing arm. Then if you start to angle the top say 5 degrees and move it up and down then you loose X amount efficiency from the shocks (cant remember the % drop), 10 degrees even more and so on till the suspension becomes useless as they are on to much of an angle to act against the force?.I believe off hand its not much more over 38 degrees from vertical (directly apposing the force) and your under 50% efficiency, but don?t quote me

So I feel that the bike looks good but the suspension will not work as efficiently as it was designed to?

 

[posplayr]

You get more wheel travel for a given amount of shock travel.

That is about all that I could figure out.

Also since the eyes are allowed to rotate, there is little resistance to rotation so there is the bending moments on the shock are not what it might appear. If the eye pivots had no friction there would be NO bending moments.

The increased angle to the vertical essentially acts like a mechanical leverage ratio but with frictionless pivots is lossless. It changes the requirements on the shock in terms of travel and also effectively reduces the spring rate (if travel is reduced).

wonder why that racer needs so much wheel travel? Riding rough roads?

 

[GregT]

In the late 70's - early 80's the Motocrossers discovered the benefits of long travel suspension and shock technology was forced to take a giant leap.
Once there were shocks capable of handling this much travel the roadracing crowd discovered that well damped long travel suspension worked real well. You could keep the rear on the ground under heavy braking for example because you could set up the bike with a lot of static sag and still have plenty of travel left.
Not particularly applcable for road bikes ridden two up though...

 

[posplayr]

In the late 70's - early 80's the Motocrossers discovered the benefits of long travel suspension and shock technology was forced to take a giant leap.

Thanks for the background