- The humble rim brake calliper
has been with us for generations.
But as bike designs change,
and rules change within triathlon and cycling,
we're seeing an emergence of disc brake
road and triathlon bikes.
And we're told time and time again
that disc brakes are more powerful,
they're better in the wet,
and their general feel is better.
And if you're like me,
you may well have just taken everyone's word for it.
But honestly, how good are disc brakes?
Well I think it's time we took a look.
(upbeat music)
So to do this, I've got two bikes with me.
One with rim brakes, whilst the other has disc brakes.
So, I've got the BMC Teammachine,
which has Shimano Ultegra disc brakes,
with a mechanical groupset.
And I have the Cervelo S5,
which has Shimano Dura Ace rim brakes,
and also a mechanical groupset.
I hear you, I hear you, they're not identical bikes,
so this isn't a true science test,
but I am stood at the top
of this lovely climb in Lanzarote,
so it seems a shame not to give them both a good run.
But to help level things out,
I have opted for the same tyres,
with identical tyre pressure in both.
I have almost identical bike position and setup
from bike to bike.
And conveniently, they're very similar in their weight too.
So what are we gonna do here?
Well, this is Tabayesco.
It's one of the most famous climbs here in Lanzarote.
It's 9.5 kilometres to the bottom,
where there are a number of good switchbacks,
perfect for testing out these brakes.
So, for this descent, I'm using our partner Shimano's
disc brakes and rim brakes.
But there are other brands available,
and I'm not testing or reviewing the brakes.
What I'm going to do is demonstrate the key differences
between the brake types.
So, let's get the stopwatches ready.
First up, I'm gonna go for the disc brake, BMC.
Run one, disc brakes.
Off I go.
(upbeat music)
Straight out of the gate I felt fast.
The brakes are responsive.
The roads are smooth.
The corners sweeping.
I was determined to set a good time.
And braking later into the corners certainly helps.
Okay, that's run one done.
I love this climb.
I felt really smooth.
Yeah, now for run two.
Just gotta work my way back up to the top now.
Ooh.
Next run, rim brakes on the Cervelo.
Let's go.
(intense music)
Right from the start it felt comfortable.
I know exactly how rim brakes work.
What they feel like, what their limitations are,
and so I was confident that my time would be pretty close.
The descent did feel more familiar on this run,
and I was happy to push it around corners,
maybe a little harder than I did
on the last go.
But this just means disc brakes will have more to prove.
Okay, run two done with the rim brakes.
Another great run.
Gonna head back to the top now,
we'll analyse the numbers.
Okay so that is both runs complete,
and I have my times here.
I was actually five seconds quicker
on the bike with the disc brakes.
Which you could actually argue,
the fact that I went second
on the bike with the rim brakes,
had a bit more experience
and I was more in tune with the descent by that point,
but I was still quicker on the disc brakes.
And then there was also the fact
that the bike with the rim brakes is an aero road frame.
This is a traditional road frame.
Again, still quicker on the disc brakes.
So that's really interesting.
And personally, I did feel like
I had a bit more power with the disc brakes.
I was able to control it a little bit more.
And I was just able to brake a little bit later.
So much so that when I rode the rim brake bike
on the second run, I actually forgot
to brake a little earlier,
and almost overcooked a couple of corners.
But anyway, those are my feelings on the braking.
I think we need to take this a step further,
and test it.
We're gonna do a brake test.
So quite simply, I am gonna approach this line
at 30 kilometres an hour with both bikes,
and stop as quickly as possible.
(easy music)
Okay, so I've done three runs with the disc brakes.
Pretty good if you ask me.
Now, it's time for the rim brakes.
(light music)
Okay, so as you can see,
I've got a little bit better on each run,
and then my final runs,
the winner was the disc brake, by about a bike length.
Okay, so discs were clearly a little bit better in the dry.
But everyone goes on about discs being better in the wet.
So I think it's time we get things a little bit wet.
What?
Not me, just the wheels!
(upbeat music)
Okay, so that's disc in the wet done.
A little bit further than before.
Now for the rim.
Ooh.
Right, so that is all my runs done in the wet.
We've taken up all the tape but my best runs.
So here is my disc in the wet,
and now let's take a walk with me here.
And here is the rim in the wet.
Quite a bit further.
It's about three, maybe even four bike lengths.
So, considerably more than when it's in the dry,
and I'm gonna put my hands up here,
this isn't the fairest test.
We are in the mid teens here in Lanzarote.
It's not particularly wet.
So, we have faked it.
The roads are dry.
We've made the rims wet.
We do displace the water a little bit quicker.
So, it's not great, but still,
an obvious difference there.
Interesting.
(upbeat music)
So that's us done for today,
and I've gotta say, I've had a cracking time
comparing disc brakes and rim brakes,
and we could be here forever really,
seeing how they compare with different riders,
at different weights, on different descents,
but I think this has given us a pretty good feel for things.
Like I said earlier, I really liked
how powerful the disc brakes felt,
and how much control I had over them.
And one thing we haven't touched on is modulation.
Now let's put this into normal terms, normal words.
Modulation basically refers to is the lever pull,
and the difference between soft and hard braking.
So what you might experience on rim brakes,
is that there's very little difference, or lever pull,
between soft braking and hard braking.
But, what we experience on the disc brakes
is that there's a lot larger range.
So, we can actually control the braking
in between soft and hard,
preventing us from locking up,
which we saw on our brake test earlier.
So I think it's worth me mentioning,
I've ridden rim brakes for my entire career.
I know how to adjust them.
I know how to fix them if I have an issue.
Disc brakes, not so much.
If I have an issue just before a race
or during a race for instance,
I don't really know how to fix them.
I don't know how to bleed them either.
So for that reason, rim brakes are always gonna be
my old faithful, whereas disc brakes though,
they do feel like the rim brakes cooler younger brother.
I feel more aggressive with them.
I feel like I can brake later.
I feel faster.
And I know you're looking to me for an answer,
and I'm afraid I just don't have one.
Personally, I really quite like the disc brakes.
I think they're great.
But I think it's really important you try them out.
Perhaps go and borrow one from a friend,
or a local bike shop, and then let us know
how you get on with it in the comments below.
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