Trivia info on the old 3-piece bushing system.
Pics are of 1971 XS1B swingarm parts.
The plastic bushings are smooth-walled, no internal grooves.
The outboard sleeves have an internal groove, plus external spiral grooves.
The interconnecting hole emerges into the spiral groove.
The early 3-piece sleeve group is about 1mm wider than the 1-piece sleeve.
The end pieces, grease seal caps, against which the sleeves bear, are 1mm thick.
The 3-piece sleeve, plus (2) 1mm end pieces, makes a width of 200.25mm.
The 1-piece sleeve, plus (2) 1mm end pieces, makes a width of 199.10mm.
The frame width of my XS1B is 200.4mm.
Fully assembled XS1B swingarm, with 3-piece system, is a close slide fit into the frame.
Fully assembled XS1B swingarm, with 1-piece system, measures out to 199.4mm.
Fitting into a 200.4mm frame opening, that's a gap of 1.0mm.
I found that it takes about 3/4 turn, and 10 ft-lbs torque on the swingarm thru-bolt nut to collapse the frame by 1mm. Decided that this is negligible, and tolerable, and bypassed fitting any additional shim washers in there...