- Will degreaser damage the bearings in your bike?
It's a question a lot of cyclists ask.
So we've decided to do an experiment.
Well, we're gonna do two experiments.
But before we crack on, make sure you click Subscribe
if you haven't already, and also click the little bell icon
as this will give you a notification
every time we upload a new video.
When cleaning bikes we often spray degreaser
around all over the place like it's deodorant.
But does liberal application of these solvents
risk damaging your bearings?
Let's first explain what degreaser does.
It's a cleaning fluid designed to strip grease,
oil, and dirt from your bike.
Now greasy oil typically isn't very soluble in water,
i.e., it doesn't readily dissolve.
However it is far more soluble, dissolves much more readily,
in organic solvents such as petrol and alcohol,
which are common components of degreasers.
So degreasers are highly effective
at removing oil and dirt from your bike.
So what's the problem?
Bearings contain ball bearings, which are then surrounded
by thick grease to help lubricate them and prevent damage.
They're also protected by seals.
Not the aquatic mammal, but little nylon covers
that are designed to make them watertight.
The thinking is that the solvents in degreasers
can penetrate the bearing seals
and then strip out the grease inside,
and the result would be a bearing
that performs like a mini washing machine full of cutlery.
We want to see if this actually happens,
so to do this we've devised some experiments.
But not just any experiments, this time we have got
some incredibly sophisticated experiments,
I just can't wait to show you. (phone ringing)
Oh, sorry, hang on.
Hang on one minute.
Yeah, hello? (mumbles)
Wait, what do you mean that the super high-tech
mega massive bearing test facility's been double-booked?
(sighs) All right, bye.
(exhales loudly) Looks like we're gonna have to improvise.
In light of the super mega high-tech massive
bearing test lab being double-booked,
we've managed to get the next best thing.
(snaps)
Yeah, that is a bottom bracket on a stick.
But it's the same one that Si used
in his excellent video, Should You Jet Wash Your Bike?
- We're really getting in there now.
Come on!
- I'm gonna spray loads of degreaser all over
the bottom bracket on a stick and then I'm gonna wash it
with water because this would replicate the cleaning process
when you clean your bike.
Now I should also point out that the bearings
have been completely packed full of fresh grease
and sealed up, so afterwards I'm gonna remove the seals
and see if any of the degreaser has been washed out
or if there's been any penetration of the bearings.
You should also remember
it's important to wear protection, kids.
Safety first. (snaps)
(dramatic music)
Amazingly used an entire can of degreaser on this chainset,
so let's wash it off now and see what happens.
This is my Charlie's Angels pose.
I'm gonna take the bottom bracket on a stick apart now
and see if there's been any penetration.
Of the bearings.
(seductive music)
I've taken the seal off, and I'm quite surprised by this,
but it doesn't appear that there's been any ingress of water
or degreaser within the bearing itself.
There is some water on the outside of the bearing
and also on the inside as well, within the axle,
but that's to be expected because this particular chainset
does have a hollow axle, but within the actual bearing
itself where the grease is there's no evidence
of any water or moisture having got in there.
So I guess this suggests that you can spray degreaser on,
well, in particular, the bottom bracket area of your bike
and rinse it off with water without too much worry
that it's gonna damage the bearings.
So I guess this means we need to do another experiment.
In this next experiment we want to look at
how resilient the seals on bearings are.
So to do this I've got four brand-new cartridge bearings
and I'm gonna create four pools of extreme bearing death.
(dramatic music)
Pool number one is degreaser, to simulate
if you rode your bike into a vat of degreaser.
Pool number two is salt water, to simulate
if you rode your bike under the sea.
Pool number three is Coca-Cola, to simulate
if you rode your bike and
crashed it into a Coca-Cola tanker.
And pool number four is water, to simulate...
Water.
All four are highly likely scenarios.
(chuckles) I'm sure you'll agree.
So in go the bearings.
(plink) (plink)
(plink) (fizz) (plink)
All right.
I'm gonna let those babies brew for a little while,
and then I'm gonna come back and see if there's any damage.
(clock ticking)
(alarm rings) Oof. Right.
I've been leaving the bearings in their solutions of death
for four hours, festering away,
so now it's time to get them out, prise open the seals,
and see if there's been any ingress in any way.
So, safety first.
Let's begin with the degreaser.
(laughs) I can't see what I'm doing.
Okay, get rid of those.
So I've taken the seal off and all the grease
appears to still be completely in there, it's untouched.
It's nice and clear, and there appears to be
no ingress at all and it's moving really nicely.
There's just really smooth, doesn't appear to be any damage
to that at all, quite surprising really, but pretty cool.
So onto the salt water.
This one's pretty interesting, actually,
because on taking the seal off it appears
that there has been some slight ingress
inside the bearing from the saltwater solution,
and the grease is actually slightly discolored,
it's no longer nice and clear, it's put a slight tint to it.
And there does appear to be some small amounts
of moisture on the inside, see?
Pretty interesting that the concentrated
saltwater solution has got inside.
On to the Coca-Cola.
The Coca-Cola one is pretty intriguing.
So the oil on the inside, or the grease on the inside
of the bearing, is no longer the clear color it was
when it first came, it's sort of turned Coca-Cola brown,
suggesting something has got inside,
and it does appear that there's a small amount of moisture
on the inside as well, and it should also be pointed out
that the exterior of the bearing is slightly browner
than the other solutions as well,
so Coca-Cola is definitely doing something to this bearing.
Right, on to the water.
The interesting thing on the water solution
is that you can see that there's a sort of a stain
leaching out the side of the bearing.
Now you couldn't see this on the other ones
because they're colored, and in the salt one
it's sort of buried in the salt in the bottom.
But it does appear that there's been some sort of ingress,
or grease leaching out of the bearing so let's take a look.
Upon taking the seal off it appears that most of the grease,
or nearly all the grease, is still intact within the bearing
which is good, but it does appear there's a slight bit
of moisture in there, and the grease in there
has been slightly discolored, it's got a slight yellowy tint
to it now whereas before it was clear.
So it does suggest that some water has got in there
and it has had an effect.
The results are really interesting,
but I guess the big question is why did we see some ingress
with the water solution but we didn't see ingress
with the degreaser solution?
Well, it's a tough one, but my best guess,
if I speculate with my science hat on,
is that it could be down to the specific gravity
of these different solutions.
So different liquids, different solutions,
have different properties, and one of those
is specific gravity.
Now, this degreaser has a lower specific gravity than water.
Degreasers often contain solvents which are less dense
than water, hence why they can sometimes sit
on the top of water as a separate layer
when you mix the two together.
Now, because water has a higher specific gravity,
that means it can be better at penetrating
the bearing seals than the degreaser.
Now what about Coca-Cola and salt water?
Well, both Coca-Cola and salt water
have higher specific gravities than water.
Only slightly, but higher nonetheless.
And salt water, well, that also contains salt,
which can cause further damage and corrosion
once it gets inside your bearings or other components.
As for Coca-Cola, well it contains a variety of things,
but it also contains phosphoric acid and carbonic acid,
which are only weak acids,
but over time they can cause corrosion.
Although degreaser is less effective
at penetrating the bearing seals than water,
it does perhaps suggest that you shouldn't be submerging
your bearings or bike in any liquid
for a prolonged period of time.
However, lightly spraying your sensitive areas
of your bike with degreaser and then rinsing it off
with water doesn't appear to cause any significant damage
at all, and this is something that's backed up
not only with what pro mechanics do when they clean bikes,
but also Si's jet wash video in which he absolutely smashed
the bearings with a jet wash and there was no ingress.
So I guess this means that you shouldn't be worried
about when you clean your bike, but just be careful
with your degreaser and your water
and everything should be okay.
Now these experiments aren't the most conclusive
and we're not professing them to be,
but I am really impressed at the resilience
of the bearing seals and also
the destructive powers of Coca-Cola.
But like any experiment it has raised further questions,
such as, what would be the effect on other bearings
on your bike, such as the ones in the jockey wheels,
or what would happen if you left the bearings
exposed to degreaser for an even longer period of time?
Well, if there's any videos you'd like us to make
and things you'd like us to test out,
then comment with them in the comments section below
and we might make a video in the future.
Right, if you'd like to do any experiments of your own
at home, then I highly suggest you head over
to the GCN shop and pick yourself up a GCN apron
to keep things clean and tiny.
And what's more, if you put it on backwards
it doubles as a cape.
And if you'd like to watch another video,
then why not check out Si's excellent video
where he jet washes bearings down here.