Chain "rubbed" top of swing arm

[uclabiker06]

Notice a nice little gash on my S2R swing arm.  Was wondering what in the heck could/would do that.  Then I realized it was the freaking chain!  I was riding without the middle cover.  Plus I kept on putting off adjusting it.  Just glad that I noticed it before things got even more ugly.   How do you know its time for a new chain anyways?  When there is multiple tight/loose spots?  14K on my bike.  

Just finished adjusting it.  I just get the chain to the point where I have to apply some pressure to get it to touch the back portion of the bottom guard.  I guess I'll wet sand that area and finish it off with 2000grit & a few dabs of clear....this sucks

[stopintime]

At 14K it usually won't have much/any life left...

Pull the chain out from the midle of the rear sprocket - more than half a tooth out = too stretched.
(there is also a specific length pr x links in the Owner's Manual)(I think)

Frozen links that won't free up with lubrication - bad chain.

Needs frequent adjustments - bad chain.

Distance from lifted to pushed down chain should be 30-32 mm. (middle of chain run)(same spot on the upper and lower run's link)

[Howie]

There is a formula for stretch depending on pitch, for a 520, 256mm. for 16 links.  No one does it.  Add to Stopintime's list reappearance of fine brown rust or any damaged O rings.  Better to err on the side of too loose than too tight when adjusting.  Too tight will kill the output shaft bearing.  14K on the original chain?  Long enough.  Replace sprockets and chain as a set.

[uclabiker06]

Well,  makes the two beasts back standing, will reaplace in that case.  Don't want to take any chances.  Thanks Howie & Stopintime...Honestly though my sprockets seem fine; I think.  Any chain recommendations?

[Dirty Duc]

Anything labeled o-ring will last as long as anything with a brand name... in my experience (but don't be tempted by "standard chain").

[kokis]

Anything labeled o-ring

What about WX-Ring?

[Howie]

X is a step better than O, less friction, longer life.  Best brand is like best anything, highly debatable.  Call our sponsors California Cycleworks and they will set you up with chain, sprockets and any tools you need.,  http://www.ca-cycleworks.com