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[jefrs]

What do I know? I'm an engineer. At one time I was in charge of the oil stores at a large MoD establishment. I had to know this stuff to do the job.



PTFE is not only non-stick but also pretty hard. Would you add finely divided high density nylon to your oil, or sand?

I'm also a physicist, Van Der Walls forces are electrostatic attraction but PTFE is used on electrical stuff because it is a good all temperature insulator that doesn't age or perish.

[jefrs]

Yes, we can and do make bearings from PTFE. We also make bearings from white metal but that doesn't make white metal a good lubricant. The 'engineering-correct' lubricant for all plastics including PTFE is petroleum jelly or silicone.



My concern with paraffin (which /is/ kerosene) is not the O-rings (which it won't touch) but washing grease out of the bearings, that grease is supposed to stay there. Hence not liking to soak the chain deep in the stuff. The best special brush is a small pot brush retired from the kitchen.

To whom it may concern, I buy the pot brushes because my hands won't fit into mugs and tumblers



You can link new chain to old chain but as the gear box sprocket can be reached with the fingers it is not necessary. If you pull the spring clip off, by rights you should replace the spring clip every time. Whilst it is ok to reuse the spring clip on a push bike, it is a safety critical component.

If you've ever seen what happens when a motorbike chain whips off - I prefer riveted chains.



I believe the stock chain to be plain pin and roller. I also like the idea of a fully enclosed chain guard. I mean come on, given the state of the roads in India I'm surprised they don't already have one even as an option.

[PeteF]

I agree that cleaning O ring chains with solvents is not a good idea. Any lubricant that is washed out of the rollers is very difficult to replace.
The chain surfaces which contact the sprockets are easy to lubricate but it's the bearing surface between the pins and rollers is the area that really needs the lubrication. The fact that a chain look oily is no real indication that it is sufficiently lubricated.

[Dennis C]

Oh my goodness Jeff, you have had so many qualifications and jobs I am loosing track of them all.

As Pete says in another thread "I bow to your superior knowledge in all things".

[PeteF]