[email protected] wrote:
> The grit that damages chains consists of practically
> invisible road dust particles, which are whipped up by the
> tires and swirl around the chain.
Dear Carl,
How do you know? What happens to the metal which comes off the chain
parts resulting in "chain stretch", and how much of the particles which
cause damage are this metal and how much is road dust? Numbers,
please, along with how you arrived at them. Otherwise you are just
guessing, no?
> The dust sticks to any oily surface, just as flies stick to
> flypaper. ...<snip> ... This faint pumping
> action gradually mixes filthy exterior oil with clean
> interior oil.
??? I don't think anyone is arguing with that so ???
> The paper towel with the ugly black streak is smeared with
> oil that has trapped road dust. The particles are so small
> that you can't feel any grittiness when you rub the mess
> with your fingers, but they eventually polish the chain
> innards until a foot of chain wears enough to elongate a
> sixteenth of an inch and needs to be replaced.
Again, agreed but what's your point? Mine is that riding in the rain
cleans your chain. Even if you are putting new roaddust into it --
even as much by riding in the rain as by riding in the dry -- you are
still only putting one day's worth of road dust into it, whereas the
rain is washing away many days of accumulated roaddust. So, even if
there is no difference in what goes in, if you ride every day and it
rains once every two weeks, then by riding in the rain you are cleaning
your chain 13/14ths of the way. If it rains every day in Seattle, then
jeverett's chain is perpetually almost clean.
Furthermore, if the rain does indeed clean your chain, then you are not
even putting one day's worth of roaddust into it in one day of riding.
Instead, since it is constantly being washed out, at the end of a rain
ride, the only roaddust you have in there is a snapshot of the last
moment you road. See what I mean? If there are 10 particles per CC of
water flying about, then at the end of the ride you have 10 times
the-number-of-CCs-of-water-in-your-chain particles in your chain. It
can't accumulate. If this snapshot represents one tenth or hundreth of
the dust available to the chain over the day, and it rains every day in
Seattle, then the Seattle rider's chain is 100 or 1000 times as clean
as the chain of the rider who rides the rain one time in ten.
> No matter how clean the roads may seem, even the air itself
> ctonains dust. Run a damp paper towel along the top of a
> window or door frame, and you'll see how much dust has been
> drifting around inside the still air.
Yeah but are you not guessing again? I mean, how many particles per cc
of air are there on a dry day, and how many on a wet day? Do you
really think that these tiny dust particles are really whipping around
anywhere near the same amounts in a downpour? I don't, but I'm not the
one making the claim. Again, numbers please, and how you got them.
> It's astonishing that such tiny particles suspended in oil
> can wear steel chains, but we have to remember that a
> slow-moving bicycle chain puts a very heavy load on a very
> small part of each pin, so heavy that the metal surfaces are
> expected to touch, despite any lubrication that we slather
> on them. Keeping them apart under such loads would require
> pressurized lubrication.
Uhm...reread the thread my friend. Noone is debating that.
> WD-40 is just too thin to fill up the empty spaces inside a
> chain very well. What doesn't evaporate or run out is still
> thin enough to squish in and out alarmingly well, mixing and
> transporting trapped dust to the worst possible places.
Yeah well that's true but it will attract less dirt too. Still
further, if you were to apply lots of WD-40 every day, you would wash
out a lot of the grit inside in the process. At any rate, more
guessing on both our parts.
dkl