Is A 1x Drivetrain The Right Choice For You?

– 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.