Wideline or Slimline Swingarm

Slimline.

With the fixing point for the enclosed chaincase also??

Jon

Also late widelines too from about 1958

Paul

A significant difference between Slimline and Wideline S/As is the lower suspension mounting lugs. On the Slimline version these are much chunkier....by around 1/16" thicker each side. There does not appear to be a definitive thickness for each blade but there is for the suspension eye slot. As a rough rule the inner blades tend to be thicker than the outers.

It is possible to mix and match swinging arms and the various featherbed frames. However, problems may arise with the mounting lug holes for some suspension units. The earlier “Wideline” frames used 12.90” long suspension units with 5/16” bolts top and bottom. The Slimline version went up a size at the top to 3/8” bolts. The bottom mounting should be 5/16” but quite a few owners drilled this to 3/8” to aid the fitting of after-market dampers.

Although quite a challenge, the early rear brake plate with torque arms can be fitted with a lug to sit in the later swinging left arm.

You summed it up to perfection, Phil.

 Pauls comment about late widelines having a slimline SA  .  I would not have thought that were so , but  its a bit like some 99 s having  650 cases   and  Some DL s having different  details in their logbooks . to  the frame numbers .