Here is description of my approach. Certainly this is not the only possible
approach and there are probably infinitely many ways to lubricate a chain. Yet,
I think my way of lubricating a chain probably gets very near the lowest possible total
cost. I already know it gives 4000 km chain life for 110kg rider on an e-bike
and does so at very minimal amount of chain maintenance work.
When installing a new chain, the factory grease must never be dissolved from
the inside of a chain. The reasons are two-fold: firstly, it is a very good
lubricant, far better than any that can be applied easily at home. Secondly,
not removing the grease inside the chain and replacing it with some other
lubricant easily saves 20 minutes of time, a valuable resource.
However, the factory grease is applied not only inside the chain but all over
the chain. From the external surfaces, it might be beneficial to remove the
factory grease by using a solvent that dissolves oil and grease, evaporates
quickly and leaves no residue. One such solvent is isopropanol. Gently moist a
rag with isopropanol and use the slightly moist rag to wipe away the factory
grease from the side plates of the chain. Some amount of the grease still stays
on the insides of the side plates that can't be easily degreased. It is
important that the rag is only slightly moist and not very wet, because a very
wet rag would let the isopropanol inside the chain, diluting the factory grease
where you don't want it to be diluted.
After a chain has been installed, it must not be relubricated if it isn't
starting to squeak, and should not be cleaned except before relubricating it
due to a starting squeak. The reason for not unnecessarily relubricating
a chain that doesn't squeak is that a chain that is running low on oil (and thus
starting to squeak) is also running low on dirt inside the chain. So by waiting
until lubrication is necessary, there is natural action that removes dirt from
the inside of the chain.
Just observe a chain that has been in use
for a long time. The rollers are shiny clean. Although you can't see it, the
half-bushings and pins of the chain are also shiny clean. Thus, if you let a
chain run low on oil, you let it also run low on dirt. This natural action
cleans the insides of the chain without needing any of your time.
The reason for not cleaning a chain that doesn't need new oil is that it
requires lots of your time. Obsessively cleaning the chain every week would
increase the cost of chain maintenance at no clear benefit.
The proper moment to lubricate a chain is when it barely starts to squeak. It may
require some skill to accurately detect the correct time to lubricate a chain.
There isn't much room for error here, because delaying chain lubrication by
100km from the optimal relubrication point is probably already too much delay.
Usually at the end of the useful life of lubricant, the chain starts to be a
bit noisy and a quiet growl can be heard from it. This quiet growl can be best
heard when riding beside something like a noise barrier that reflects the sound
from the chain to your ears. Then at some point of time, very soon after the
quiet growl can be heard, slight squeaks can be heard occasionally from the
chain. At this point of time, the squeaks are not loud and are not continuous.
They only occur during some point of chain movement, probably coming from
individual links that happened to have less lubricant than most chain links.
This is the moment when the chain should be brushed externally and
relubricated. Leaving the chain unlubricated would make the slight squeaks
worse, and develop a continuous squeaking sound of an unlubricated chain.
It is important here to properly detect the correct moment. Once I measured a
chain to be well below 0.5% wear and slightly later detected barely starting
squeak from the chain. I delayed the lubrication of the chain, thinking that
it's not probably completely dry of oil, so there might be still a very little
grit inside the chain. The squeak became worse and worse. Then when I no longer
could tolerate it, I thought it's now a good moment to lubricate the chain --
after all, practically all dirt inside the chain is gone now. The chain was
already worn, despite being well below the 0.5% limit only slightly earlier.
The lack of oil caused accelerated chain wear.
Before doing any work on an old chain, its wear must be checked. The proper
wear limit to discard a chain is 0.5%. A proper tool must be used: only Shimano
TL-CN40, TL-CN41, TL-CN42 and Park Tool CC-4 are known to be accurate. Most
chain tools are junk: http://pardo.net/bike/pic/fail-004/000.html -- an
alternative to Shimano tools and CC-4 is to use an inch ruler, but there are
several drawbacks of this approach: (1) it requires accurate eyesight and well
lit area, (2) it requires a ruler at least 12+1/16" long (so in practice you
are looking at very long rulers like 24" rulers because they don't sell
12+1/16" rulers) or a ruler 12" long plus extrapolation to guess where the
12+1/16" mark would be, (3) it requires a ruler with inch scale as opposed to
millimeter scale and an inch ruler may be hard to be found in the metric world.
When lubricating a barely squeaking chain, the rollers, pins and half-bushings
of the chain are shiny clean. The only dirt is on the insides and outsides of
side plates. This dirt should be ideally removed on the bicycle, as removing
the chain and cleaning it off the bicycle would require too much time. The best
way to clean the chain is by two stiff brushes, such as nail brushes or
vegetable brushes. Ideally the brushes should be plastic brushes as wooden
brushes tend to have the strings to fall off easily. The on-the-bike cleaning
machines require lots of solvent that needs to be disposed of properly, make a
huge mess because the solvent drips everywhere from the chain, and leave the
solvent inside the chain necessitating you to wait for its evaporation, thus
requiring lots of waiting time. Thus, the on-the-bike cleaning machines should
The cleaning of the chain is important here because oiling a chain carries dirt
to the inside of the chain, and thus reduces chain life. Normally you don't
unnecessarily clean a chain, but when lubricating it improves the chain life if
you clean it.
The two stiff brushes are ideally used when the bicycle is mounted outdoors in
a workstand (doing it indoors would make the floor dirty). The two stiff
brushes are first used to scrub the outsides of side plates of the chain, on
left and right side of the chain. When the chain is externally clean, the two
stiff brushes are then moved to above and below the chain, so that the brushes
scrub the insides of the side plates of the chain. This cleaning of insides of
the side plates is slightly more challenging than the cleaning of the outsides,
as the brushes are at an inoptimal angle. Yet, a reasonable job can be done
When the chain looks visibly clean, it is lubricated with a thixotropic spray
type motorcycle chain lubricant. Here it is important to underline that the
lubricant should be one made for motorcycle chains. A bicycle chain is a low
tech application and can be lubricated with practically any liquid, including
water (although water evaporates quickly so it won't lubricate for long, and
leaves the chain rusty). In contrast, a motorcycle chain is a high tech
application and requires a proper lubricant. Because of these differences, most
lubricants sold as bicycle chain lubricants are total crap, sold for 20 euros
per 50 milliliters (costing the manufacturer only 2 euros per liter or 0.1
euros per 50 milliliters). A spray type motorcycle chain lubricant is more
likely to be thixotropic.
The thixotropy is a shear thinning property. A thixotropic lubricant if left to
settle, becomes very thick. Thus it stays in the chain and doesn't fly away. If
agitated (such as by shaking the spray bottle or spraying it), it becomes very
thin, easily penetrating to the innards of the chain. This thixotropy property
can be tested by shaking the spray can, spraying it in a glass container,
agitating the glass container and seeing how thin the lubricant is (it should
flow easily). Then after leaving it settle for an hour or two, it can be
gently agitated again and it should not flow easily anymore, unless agitating
it enough to make it thin again.
The spray lubricant bottle must be shaked first (this shaking activates the
thixotropic lubricant making it thin enough to flow to the innards of the
chain). The spray lubricant is sprayed on the rollers of the chain. From the
sides of the rollers, it goes to the insides of the rollers, and from the gap
between two half-bushings, it goes to chain pins. Unfortunately, some of this
lubricant stays on top of the rollers, and on insides or outsides of the side
The excess spray that stayed on the outsides of the chain is wiped away, first
using a dry rag to remove most of it, then if wanting to do a very thorough job
of removing it from the surface, using a rag gently moistened in isopropanol to
remove the remaining thin surface layer. Note the rag should be only gently
moistened with isopropanol and not fully wet with isopropanol, as you want to
avoid any possibility of isopropanol flowing to the innards of the chain and
diluting the applied lubricant.
After lubricating a chain, it should be good for 1000 km in dry weather. If
riding in wet weather or if expecting to get the chain coated in mud, it might
be beneficial to omit removal of the surface oil layer.
This way of lubricating a chain has the following cost structure:
- Chain: costs 1 hour of work to pay for it and lasts 4000 km for 110kg rider on an e-bike
- Chain installation and removing surface grease at 0 km: 20 minutes
- Chain cleaning and lubrication at 1000 km: 20 minutes
- Chain cleaning and lubrication at 2000 km: 20 minutes
- Chain cleaning and lubrication at 3000 km: 20 minutes
Thus, the total cost is 35 minutes per 1000 km.
The 4000 km chain life was based on measuring a soon-to-be-lubricated chain
with 3000km using Shimano TL-CN41, and it still was slightly below the wear
limit. I know the lubricant lasts 1000 km, so I know the next time I measure
the chain will be at 4000 km (and I suspect TL-CN41 will tell it's worn then).
Note that usually 4000 km is considered a good chain life for average user, and
that e-bikes plus heavier-than-ordinary riders should see reduced chain life.
So, given the application (110kg rider + e-bike), the 4000 km chain life is