Disc Brake Hacks For Road Bikes | Road Bike Maintenance


– Ah, disc brakes. The
hardest to look after than rim brakes. Possibly
just a little bit. But the main reason for that is because they are different to what
most people are used to. But with the tips and the
hacks which are coming up You should be well on your way. [Upbeat Music Playing] Firstly, let’s have a look
at the very annoying case of disc brake rub, essentially
where the brake pads are rubbing against the rotor.
A few things to check, but the first one you should
do is simply to loosen the mounting bolts here. Slacken them right off, then
hold your front brake on. This is the left brake
front bike at the moment. Hold it on nice and tight. Do the whole system back up again, preferably with a torque wrench like this, and give the wheel a spin
and see if that has solved your problem. In a lot of
cases it will have done, but with flat mount discs in particular it can be a little bit more complicated. For the hack, you are going to need some kind of business card.
I’ve taken Si Richardson’s, And you’re also going to
need to take the wheel out, which for this particular
bike is a 6mm Allen key. Drop it out briefly,
then you’re going to take your business card and bend
it over the rotor like so. And once you’ve bent your card into shape, insert it into the calliper. Then, put your wheel back in. (upbeat music playing) Then we are going to loosen
the calliper off again, as we did before, and the
width of that business card should be just the right size to space the pads out nicely. So pull your brake on again.
Should be all nice and centred and then you can do it back up with your torque wrench again. Then you are ready to drop
the wheel back out again and remove your business
card. And then hopefully… And you put your front wheel back in. And tighten the whole lot
up. Everything should be perfectly centred, and no sign of any disc rub. Perfect disc brake hack. (music playing) Now, it’s fair to say that
for the majority of us disc brakes are relatively
maintenance-free, and that is a fair reputation,
but if you ride a lot in bad weather there is something else that you need to know
about and be aware of. And that is sticky pistons.
The pistons are essentially what’s inside the calliper
here, which pushes the brake pad onto the rotor, and they can
occasionally become sticky. They’re in their own little oil bath, and you’ll be able to tell
by looking inside them. It won’t necessarily be evident just by pulling the brake lever on here. So, to get access to them,
you need to remove the wheel, and also remove the brake pads. Then once you’ve got the pads removed and the pistons exposed, you
want to pump the brake lever a few times to pop them slightly out. Make sure you don’t go over
the top when you’re doing this because it’s very easy to pop
the pistons out completely, and that would mean a full re-bleed. So, just a few times
until you’ve got around three to four millimetres
exposed on both sides, at which point you’ll want to get yourself some alcohol spray and a nice, clean rag, and clean the non pad-facing
side of the piston. So, effectively, the bit
that’s around the edge that needs to be nice and clean
when it’s going in an out. [Upbeat Music Continues] If one piston is particularly sticky, what you might find is that
the other piston has come out and is exposed, but one is left hidden. And that situation, what you want to do is spend the first part of your time cleaning the exposed piston,
and then using something like a plastic tyre lever,
push that one back in. And then with the fluid
that’s in the system, it should be enough to push
the slightly sticky piston out. Then, once they’re all cleaned and dried, push the pistons back inside the calliper using a plastic tie lever,
and then give the brake a few pumps, just to check
that they are now moving up nice and evenly. Then you just need to put the
brake pads back in like so, and hopefully that will
have solved your problem. And then stick your wheel back in. Looks nice and aligned already. Perfect. Right. Next up is a hack
which comes from our very own GCN mechanic Tom. Not
Tom Last, you understand, but someone that actually knows
what they are talking about. So, if your brakes are
starting to feel a bit spongy, The first point of contact
with the pad at the rotor, you can then pull the brake lever on it significantly further. Then it might be that the whole system needs to be re-bled,
which is quite a big job. However, if that has been
done fairly recently, you might want to check
this next hack out. For it, you are going
to need a bleed bucket, and also some fluid which
is specific to your brakes. First up, you’re going to want
to put your brake-specific fluid into the bleed bucket. Fill it up around about a third. And then put that to one side. Then you want to expose
the bleed port screw, which would be underneath
the rubber hood here, and undo that with a 2.5mm Allen key on the Shimano brake. Pull that out, put it
carefully to one side, and then screw the bleed bucket in. Right. And then to do the
actual hack part of this we’re going to take the
bike out of the stand. And put it on the floor. Right. Then, take the top of the bleed bucket off and remove this plunger from inside. Now, squeeze the brake lever
on and off a few times. Do it as tightly as you can. And what you should be encouraging
is any air in the system to be coming up towards the top. And you might, in fact,
see a couple of bubbles coming through the fluid
in the bleed bucket there. Now here’s the actual
little hack bit, though. Take the top part of the
bleed bucket and replace it, and then just gently squeeze the brake whilst also gently tapping the front wheel up and down on the
floor. And that will give an extra bit of encouragement to any air which is trapped in the
system, which could be well be the cause of your spongy feeling brakes. And hopefully that will
have solved your problem. Don’t forget, though, to
put the plunger back in before you unscrew the bleed bucket. Otherwise, you’re gonna
get fluid everywhere. Right. Then, back on with the screw. It will need a quick wipe-over. Hood back on. And it feels a lot more solid. Now, if it is the rear brake
which is feeling spongy, then when you are doing
it you can do exactly the same method, but when it comes to bouncing
the bike up and down, use the gravity to your advantage so that the air comes upwards. The bike here, just bounce
it gently at that point whilst pulling the brake lever on it. And those three hacks
should solve a lot of your disc brake problems. One
more thing that you can try if you are finding you’re
getting air in the system, is to focus on the points
where air might be getting in. So, for example, the
part here which connects to the cabling parts here.
Expose the bottom part which normally got a rubber seal over it, and on this case it is an
eight millimetre spanner there, and then a nine millimetre
here, and just check that these are nice and tight. You can also see whether there’s any fluid around there. Wipe that off with a
rag. Go out for a ride. Because everything will still be safe, and then expose it again
and see if there is any more fluid starting to leak out. And another final tip, which
you might not think about if you are new to disc brakes
as I was a few years ago, And that is when you are
travelling, you want to try and prevent the brake pads coming together and the pistons coming out. So to do that, you can get specific spacers like this, which you can put in before
you go into your bike bag. Or, if you haven’t got
one, you can simply use a couple of business cards
with a very thin coin inside. And that should do the trick nicely. I would love to know how you
get on with all these hacks. You can do so by letting us know in the comments section down below. And if you’d like to see Si Richardson taking a first look at the
Dura-Ace disc brake group set a few months ago in 2017, you can find that in the
bottom corner just down there. On the other hand, if you want 10 more general cycling hacks, you can find them in the top corner up there.
And make sure you subscribe to the Global Cycling
Network. It is free to do so. All you’ve got to do
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