Suspension relay arm

[roortcloud]

Greetings gentleman
Can anyone tell me with certainty the reason why the suspension relay arm of the 1989-90 is longer overall than the 1991 and later models?
I know the lower shock mounting point on the suspension relay arm is wider and offset to one side on later models, (thanks to Pat for the picture of the 2 parts side by side) but why is the mounting point to the frame shorter?
All bearings and associated parts for the frame and swing arm pivot points are the same. (only the shock mount bearing & associated parts are different)
This leads me to believe the width of these pivots (axels) are the same from 1989 thru later models.
Also, can anyone say with certainty that the frame and swingarm mounting positions for the suspension relay arm are in the same location for models 1989 thru later models?
Not offset to one side or the other.
Thanks for your help

Ron

[roortcloud]

Gentleman,
I should have clarified the swing arm mounting point is actually the dog-bone to swing arm mounting point.

[aviationfred]

The are a few factors in play that may be the reason that the 2 relay arms are different lengths. I don't know if any 1 difference or all differences combined is the reason.

1) The frame is different between the 1990 and the 1991.

2) The 1991 and later models needed room for the ABS pump. The position of the upper shock mount could be higher, or lower.

3) The swingarm is different. The 1990 is made of aluminum, the 1991 is made of steel.


Hope this sheds some light.


Fred

[Bozo]

Sorry to highjack the site but I do have a question about the rally arm / suspension.

Both my 89 model when on the main stand and I put a small crow bar under the tyre I can get around 10mm or 3/8" free ply, I tried tightening, replacing the bearings, I have a new Penske on one / Nitron on the other etc and I am finding it impossible to eliminate the ply to a reasonable amount- maybe 3 mm.

I am aware that 1mm ply in the front of swingarm = 4 to 5mm at the back.

Or is this ply common? Over sharp bumps I am certain this ply can be felt

[Pat Conlon]

On the center stand with the back wheel under full droop, a small amount of play is to be expected. No big deal. Remember when the weight is placed back on the suspension, this play disappears.

[Millietant]

Sorry to highjack the site but I do have a question about the rally arm / suspension.

Both my 89 model when on the main stand and I put a small crow bar under the tyre I can get around 10mm or 3/8" free ply, I tried tightening, replacing the bearings, I have a new Penske on one / Nitron on the other etc and I am finding it impossible to eliminate the ply to a reasonable amount- maybe 3 mm.

I am aware that 1mm ply in the front of swingarm = 4 to 5mm at the back.

Or is this ply common? Over sharp bumps I am certain this ply can be felt

That sounds like bearing where the bottom shock mount connects to the relay arm is shot. If you have 10mm of movement it's way too much. As Pat says, it'll never be zero, but 10mm is ridiculous. I think mine was about 1mm after I fitted a new bearing. It's not a difficult job and I'd guess RPM have the part in stock.

It's the one where the red circle is in this photo.

[Millietant]

Photo now attached

[Bozo]

Sorry to highjack the site but I do have a question about the rally arm / suspension.

Both my 89 model when on the main stand and I put a small crow bar under the tyre I can get around 10mm or 3/8" free ply, I tried tightening, replacing the bearings, I have a new Penske on one / Nitron on the other etc and I am finding it impossible to eliminate the ply to a reasonable amount- maybe 3 mm.

I am aware that 1mm ply in the front of swingarm = 4 to 5mm at the back.

Or is this ply common? Over sharp bumps I am certain this ply can be felt

That sounds like bearing where the bottom shock mount connects to the relay arm is shot. If you have 10mm of movement it's way too much. As Pat says, it'll never be zero, but 10mm is ridiculous. I think mine was about 1mm after I fitted a new bearing. It's not a difficult job and I'd guess RPM have the part in stock.

It's the one where the red circle is in this photo.

I'll recheck these points thankyou for your input. Unfortunately Western Australian roads have sharp pot holes which makes the free ply standout