856 Elastomer Dimensions; Possible Alternative

[jmf003]

I measured the elastomers on my 856.  Results were:

Front      
  Shaft diameter   0.394 in
      
  Bottom elastomer      
    Markings 150 stamped on top (might be 50 with a spurious mark in front)
    Length 1.305 in
    OD 1.719 in
    ID 0.406 in
      
  Top elastomer      
    Markings 70 stamped on side
    Length 0.937 in
    OD 1.651 in
    ID 0.395 in
      
Rear      
  Shaft diameter 0.394 in
      
  Bottom elastomer      
    Markings 80 stamped on top
    Length 1.385 in
    OD 1.702 in
    ID 0.402 in
      
  Top elastomer      
    Markings 100 stamped on top
    Length 1.334 in
    OD 1.634 in
    ID 0.400 in

The alternative is what I posted in a separate thread: part numbers 9.8141 and 9.8112 from http://www.energysuspension.com/universal-products/shock-eye-bushings.html. 

Compared to the original elastomers, the Energy Suspension bushing have these characteristics:

  OD is smaller; might compress too easily?
  ID is larger; may need fitting to keep from moving?
  Combined length is longer; may limit travel? 
  Shore durometer unknown

Pictures follow.

[w2zero]

Got a drill press?  You can set a scale on the table and then use the dp to compress the elastomer a fixed distance to determine what the spring rate is.  Just set the guage on the quill for your measurement on contact. 

[jmf003]

Got a drill press?  You can set a scale on the table and then use the dp to compress the elastomer a fixed distance to determine what the spring rate is.  Just set the guage on the quill for your measurement on contact. 

Great suggestion on the DP.  I'll have to give that a shot.

I dealt with the oversized ID by picking up some 3/8 hose from an auto parts store.  3/8 is a little undersized but  a little elbow grease coupled with some lithium grease did the trick.  OD on the hose was 5/8, which was perfect.

I installed the bits on my bike and took it for a quick spin on city streets.  The ride felt great.  Not rock hard like the original elastomers but still taut. 

[spikebender]

I tried some used rubber bushings of a Toyota pu once they worked great, But they were old and blew out pretty quick. never gave it much thought about trying new ones. think I'll have to look to this.

[jmf003]

Well, I can't complain about the price.   I think I spent $14 + shipping on the suspension bushings.  The local auto parts store gave me the hose for free out of their scrap pile.   Nice guys.