RK O ring.def way more heavy duty than the renolds i got from hitchcocks.
amazing what a difference a new chain makes. its sooo smooth now...
the old chain was surging, rubbing, stretching. lesson learned here to take note of when a chain is stuffed and what the symptoms are.
Glad it's sorted. A quick check to see if a chain is done is just two things:
1) Are there any frozen links?
2) Grab the chain at the back of the rear sprocket and pull it away from the sprocket. If it comes away far enough for you to see light between the chain and sprocket, it's done.
You can do this in two minutes on any bike. Yes, you can try to free up the frozen links but it's on it's way out. You can tighten it a bit more but it's on its way out. A lame chain can cause all kinds of weird symptoms, just replace it now and don't get something cheap.
Scott