Bronze bushing swing arm modification

[Dellortoman]

Just a guess, but I reckon the bridge-like swing arms on modern bikes, and frame bracing around the pivot are to cope with twisting loads rather than axial loads.

 

[sfcpiet]

Only advantage an axial roller/ball bearing would have over the simple plastic thrust washers is a reduction in friction.  Not that there is much that influences swingarm action in the first place, leverage ratio would probably overcome a solidly siezed axle!

The plastic thrust washers show minimal wear, even over high mileages and mediocre lube routines, so no real axial forces to speak of.

The stock swingarms may seem a bit weedy, but I have never found them lacking in stability, except once the bearings show excessive play.  I no longer bother with reinforcing the swingarm pivots either, haven't found any advantage on my track bike through that.  The distance between lower and upper rear engine mounts is small enough to keep the swingarm pivot plate in its' place, won't find much distortion there! 

piet

 

[chrisk]

Nothing to do with me and not something I would bother with doing, not much in the way of side thrust on the swing arm. The little nylon washers the factory fitted seem to do fine locating the swing arm and keeping dirt out of the bearings.


    Keith

New I'd seen it somewhere, see Bobs post #4 with picture.
http://www.laverdaforum.com/forum/index.php/topic,42215.msg74169.html#msg74169