- Pro cycling team Aqua Blue recently announced
that they would be using 3T frames
for the 2018 season.
It caused something of a ruckus.
Firstly because the frames are disc brake only.
So controversy one.
And then secondly because you can't use
a front derailleur with them.
It just won't fit.
So they have to use a 1x drivetrain.
Controversy two.
Now many people were therefore wondering
exactly what the team is gonna do.
My opinion though is that it's perfectly possible
to race pro races with a 1x drivetrain.
And this is how I think it can be done.
I appreciate though that many of you
will not be interested in knowing how to race pro race
on a 1x drivetrain,
so I'm gonna go through the why's and the wherefores.
And then I'm gonna talk about gear ratios just for fun.
All right, just for fun. I'm kidding.
Now, if you don't know what a 1x drivetrain is,
then let me explain.
It's where you have a single chainring
and therefore no need of a front derailleur.
But to get the spread of gears that you need,
you have a correspondingly
wider spaced cassette at the back.
But then, to make sure the chain is nice and secure
and it doesn't bounce off,
you need a rear derailleur with a clutch mechanism.
So that it holds it nice and tight.
And you also need a specific chainring
called a narrow-wide chainring,
which likewise holds the chain really secure.
Now single chainring hubs have been around
since forever basically.
But SRAM actually launched the first dedicated system
on mountain bikes back in 2012.
It's been hugely popular since then
and then also recently off-road on gravel and cyclocross
after they launched Force 1 in 2015.
But it is catching on on the road as well.
Before we get onto how, let's tackle why
you might wanna use a 1x drivetrain.
Because for normal cyclists like you and I
it's less maintenance,
and it's easier to set up 'cause you only got
one derailleur to worry about.
It can also be lighter depending on the exact combination
of sprockets that you choose to use.
It's also quieter.
On anything rougher than tarmac, there is no chain slap
because that clutch derailleur holds the chain
nice and tight.
And then personally, I also just think
there's something really nice-looking, super-clean
about that front chainring sector.
But then, things get really interesting,
and by that I mean really geeky,
when you start to consider frame design as well.
'Cause if you go back to mountain bikes,
who have had it for longer, like we said,
if you get rid of the need for front derailleur mounts,
you get an awful lot more freedom
with your suspension design.
But then relevant to us,
you can also make the chainstay shorter
to make the bikes more nimble, more lively.
Which is exactly what we did with the GCN custom bike.
As you can see, the chainstays are insanely short,
but yet there is no problem with gear performance
because we're using a 1x set-up.
And the same is true of the Aqua Blue bike,
the 3T Strada.
Additionally, that also being an aerodynamically
optimised bike has the added benefit
of removing that inner chainring and front derailleur
which supposedly makes you faster.
And I guess if you look at Tony Martin's TT bike,
you probably get that impression.
So you get a more reliable and a quieter
and potentially faster bike.
And yeah, I would like to stress this point.
Although SRAM have helped us to make this video,
this is my opinion.
As it always is, in fact, every time I open my mouth.
Unfortunately.
So how is it all gonna work then?
I can't speak for Aqua Blue specifically.
They're remaining tightlipped for the time being at least.
But this is my theory.
Let's say that for 98% of race days,
a pro cyclist will use chainrings like this,
which are 53/39.
And that'll be paired with an 11-28 cassette at the back.
To replicate the exact spread of gears with 1x,
you would need 50 tooth a chainring
and a 10-36 cassette.
Unfortunately at the moment, SRAM don't actually make
a 10-36 cassette.
They may well do in the future.
I don't really know.
So, if we're talking about what's available now,
I would go for a 52 tooth chainring
and then one of these, which is an 11-36 cassette.
So yeah, your top gear is every so slightly smaller.
But to put it in context,
it's the difference between 59.5 kilometres per hour
and 60.5 kilometres per hour
when pedalling at 100 RPM.
Now personally I could live with that,
especially when you take into consideration
the potential aerodynamic advantages as well.
However, it's not quite as simple as that.
Because a lot of people, particularly bike racers,
will point to the fact that
when you've got a wider ratio cassette,
you have slightly larger jumps between some of your gears.
Which can be particularly uncomfortable,
particularly when you're chewing on your stem
and grovelling in a gutter,
which are abiding memories of mine, let's put it that way,
from my cycling career.
But if we look at it objectively,
the difference between this cassette and this cassette
are two cogs.
Your 14 tooth cog and your 16 tooth cog.
How wedded are pros to 14 and 16 tooth cogs?
Well, quite.
Is that rational?
I don't actually know.
It doesn't bother me in the slightest now,
but I'm not racing and I didn't try it.
Of course there are gonna be those 2% of race days
where extreme gear ratios are needed.
And so what is gonna be called for in that situation
I hear you ask.
It's one of these.
Check it out!
A 10-42 cassette.
You pair that with a 48 tooth chainring,
and you end up with an equivalent spread of gears,
unbelievably, is 53/36,
which technically, remember, isn't even allowed
and an 11-32 cassette at the back.
Absolutely massive.
Now of course, you are gonna miss
a few more gears in there.
Although actually you will get your 14
and your 16 tooth sprockets back.
But do bear in mind that the slower you go,
so in super mountainous terrain,
the larger the jumps you will need in your sprockets anyway.
And then if you're not doing pro races in the Dolomites,
one of these is actually great
for day-to-day riding as well.
Personally, as you can see actually
from that GCN custom bike,
I use a 50 tooth chainring up front
and this 11-32 cassette at the back.
Now that admittedly only gives me a low gear equivalent
of 39/23, which is pretty old school
but that's kind of how I like it.
If I did live near any longer and steeper climbs,
then I'd use that one, which is 11-36.
But you shouldn't be afraid
of trying smaller chainring sizes either.
A 46 feels absolutely great when you get it spinning
on the road.
And then when I'm riding off-road,
I use a 42 tooth chainring.
When I'm racing cross, I use an 11-32.
When I'm doing super events,
like the Dolomites Superbike or the 3 Peat Cyclocross,
I use this.
In fact, this very one.
And I think that mud is actually 3 Peat's mud.
After that it's rather complex
but absolutely fascinating trip through gear ratios.
And what I think you should bear in mind
is that it is very straightforward to actually get
the same spread of gears of 1x
as it is to a conventional two-by set-ups.
But you will have some slightly larger gaps
between sprockets.
Now personally, that doesn't actually bother me.
But, I can't vouch for pros
because I don't have to grovel in gutters anymore.
Yes!
Not very much anyway.
So that's how it might work.
What's the hardware that you might need then?
Well firstly we've got the specific rear derailleur.
So as I mentioned, it's got a clutch in it,
a one-way roller-bearing clutch that keeps the chain
nice and tight and nice and secure.
I you're gonna use an 11-36 cassette,
you need a medium cage.
But if you're gonna use that whopping 10-42,
then you need a long cage mech.
Then we've got specific chainring.
Because it's designed not to shift, as opposed to shift,
the teeth profile will be a lot higher.
And they also alternate between being narrow and wide
'cause then that gives a nice secure fit with the chain
and the correspondingly narrow and wide links.
And the only other part that's different really
is the left-hand shifter
which isn't much of a shifter at all anymore.
In fact, it's not, is it really?
It's just a brake lever.
Then, one last point to mention.
If you are gonna use that 10-42 cassette,
you will need one of these,
which is called an XD driver.
And basically it replaces a standard free hub body
for one that is a little bit smaller.
Because an 11 tooth sprocket
is the smallest diameter sprocket that will fit
on a standard cassette.
So if you wanna ride a 10, you need something different.
The only way you can tell whether it will fit your wheels
is if you consult your manufacture, whoever it is.
But in this case, with the Zips, super-easy.
Pull one off, stick the other back on there.
Now, it is gonna be fascinating, I think,
to work out what comes next for 1x on the road.
I suspect probably a wider choice of gear ratios,
for a start,
and a number of different cassettes.
But then I think it's inevitable that we're gonna get
that 12th sprocket at the back.
The reason I say that is because mountain bikers
have already got it.
In fact, just after you click on the globe to subscribe,
if you haven't already,
it'd be well worth a look at GMBN's video
about that 12 speed SRAM Eagle drivetrain.
'Cause that could well give us a bit of a glimpse.
Although I don't know for certain
but, you know, if I was a betting man,
that's what I'd go for.
Then if you want to know about a little bit more
on pro gear ratios,
and I don't know who wouldn't,
then click just over there for that one
from the Tour de France as well.