Fri May 23 11:20:28 1997 - Message No. 894
From: "Robert Rowe"

Subject: "O" Ring Chains


@ Riders

The statement was made yesterday that "O" ring chains are sealed and
should remain so for life and therefore do not require external
lubrication.

I spoke to a friend who is a Mechanical Engineer and who uses chains in
his designs and he said that this was not true.

He agreed that there is grease behind the "O" and that this did ensure
enhanced life but that the "O" ring is made of a material that dries out
and shrinks allowing the grease to escape and dirt to be trapped between
the ring and the chain. This dirt abrades the "O" ring further reducing
its sealing properties, starting a vicious cycle that eventually turns
an "O" ring chain into a normal chain.

Using a Scott Oiler or using chain lub keeps the "O" ring supple and
prevents the ingress of dirt, increasing chain life.

I'm more than happy to take this discussion off line.

Yours

Rob



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