Saw an earlier post regarding chain cleaning. An excellent product is WTK Chain Cleaner by wtkchemicalsolutions.com. Used it last year after being bad and not cleaning for a few thousand kms, did what it said, "spray on and hose off" and it gave me the new looking golden chain that I had driving out of the showroom that first time. Definitely worth the $10.00 Canadian. They are based out of Markham, Ontario just north of Toronto. My chain still looks good. Won't hurt o-rings.