Whilst several knowledgeable members have thankfully provided lots of data about the diameters and lengths of the various spacers required in the "stack up" along the swinging arm assembly especially on the DC singles and twins, the following may be helpful.
I needed to replace the swinging arm rubber in torsion bushes and spindle on my 20DC. The existing spacers could not be correct as two of them were loose axially on the spindle.
It seems to me that the length of all the spacers and the thickness of the engine plates and frame lugs is very critical since they should pull up tight against the inner swinging arm bush tubes when bolted up. This ensures that the rubber in the bushes flexes in torsion with movement of the rear suspension. The inner steel tube part of the bush should not rotate around the spindle. (should they ?)
The correct length of these spacers also ensures the the engine plates are in the correct location so that engine to rear wheel alignment is maintained.
The problem that I found is that if I made the spacers exactly to the Greeves drawings the above wasn't achievable. Whether the frame lugs were the wrong distance apart or the (longer) inner steel tubes in the bushes (new from Villiers) are a different length from the originals or even the fixed spacer at the bottom of the battery box is incorrect, I don't know.
My own experience suggests that it may be prudent to consult the factory drawings but also measure your own dimensions to ensure that the correct "stack up" is achieved. In this way you can unsure that there is no undue load on the frame lugs other than what they were designed for. If any of the spacers are too short, tightening the two nuts will greatly overload the bronze welded joint on the frame lug.
I ended up with all three bushes slightly different from the factory drawing. Albeit by only a small amount.
Trust the above is of some help.
I needed to replace the swinging arm rubber in torsion bushes and spindle on my 20DC. The existing spacers could not be correct as two of them were loose axially on the spindle.
It seems to me that the length of all the spacers and the thickness of the engine plates and frame lugs is very critical since they should pull up tight against the inner swinging arm bush tubes when bolted up. This ensures that the rubber in the bushes flexes in torsion with movement of the rear suspension. The inner steel tube part of the bush should not rotate around the spindle. (should they ?)
The correct length of these spacers also ensures the the engine plates are in the correct location so that engine to rear wheel alignment is maintained.
The problem that I found is that if I made the spacers exactly to the Greeves drawings the above wasn't achievable. Whether the frame lugs were the wrong distance apart or the (longer) inner steel tubes in the bushes (new from Villiers) are a different length from the originals or even the fixed spacer at the bottom of the battery box is incorrect, I don't know.
My own experience suggests that it may be prudent to consult the factory drawings but also measure your own dimensions to ensure that the correct "stack up" is achieved. In this way you can unsure that there is no undue load on the frame lugs other than what they were designed for. If any of the spacers are too short, tightening the two nuts will greatly overload the bronze welded joint on the frame lug.
I ended up with all three bushes slightly different from the factory drawing. Albeit by only a small amount.
Trust the above is of some help.
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