The groupset arms race takes an interesting turn today with the release of Rotor’s 1x13, 13-speed hydraulic groupset that is adaptable for road, mountain, cyclocross and gravel riding.
The highly modular drivetrain is near production and BikeRadar is pleased to share the worldwide exclusive first look at this fascinating groupset.
- Rotor's latest cranks and hubs tested, plus more time with the UNO hydraulic groupset
- Road bike groupsets: everything you need to know
For the sake of clarity, please note that the groupset is simply called ‘1x13’ — no catchy names here!
This article was updated with new pictures at 13:00BST, 8 July 2018
So why go 13-speed?
The Rotor 1x13 groupset is the first 13-speed production groupset.
We seem to have only just landed in the 12-speed era, so adding yet another cog will no doubt confuse some, but there’s sound logic behind the decision; although a 2x11 groupset has 22 theoretical ratios, the effective number of usable combinations is usually only 14, due to overlap between different chainring and sprocket combinations. (There are, of course, triple chainsets to consider, but these have fallen out of favour in the mountain bike world and have almost never been used in road racing.)
With that in mind, a 13-speed groupset takes you most of the way to having these 14 useful combinations.
It is, of course, possible to replicate the range of a normal double setup with a 1x12 groupset, but critically, the jumps between will be large. A 13-speed groupset allows for smaller jumps between gears, particularly on smaller-sized, road-focused cassettes.
Why not go 14-speed?
You could be forgiven for wondering why Rotor has not just gone the whole-hog and jumped straight to a 14-speed setup if it would result in the same number of usable gears as a 2x11 groupset.
I can’t speak on the behalf of Rotor, but if this patent from Shimano — filed way back in ’99 and covered by BikeRadar last October — is to be believed, fitting a 14-speed cassette onto a regular freehub body, at least in more compact ratios, would require a radically different chain design.
That the groupset is 13-speed will likely upset many (many who probably won’t buy the groupset, but I digress), so introducing a new chain as well may have actually broken the internet.
Do I have to buy a 13-speed chain now?
You’ll be pleased to hear that as the spacing and size of the cogs is the same as a 12-speed cassette, the new groupset uses a run-of-the-mill KMC X12, 12-speed chain.
What is the range of the 1x13 Rotor groupset?
The groupset has a maximum range — with the 10-52t cassette — of 520%. This presents a 1.96% increase compared to Shimano’s recently announced 12-speed 10-51t XTR M9100 (510%) cassette.
As well as the 10-52t cassette, there are also 10-36t, 10-39t and 10-46t cassettes available.
The three smaller cassettes are primarily intended for road/gravel/’cross use, with the largest reserved for mountain bikes. However, it is suggested that the 10-46t may also be useful for those looking for a closer-spaced ratio off-road.
Likewise, if you’re particularly fond of slogging up wall-like alps, there’s also nothing stopping you using the very largest cassette on the road.
While the move to 13-speed is, of course, very interesting, this simple cross-compatibility is what, on paper at least, makes the groupset stand out.
What chainrings are available?
To cover every possibility across all disciplines, chainrings from 38 to 54t are available in two-tooth steps on the road side and 26 to 40t for mountain bikes.
The chainrings will be available as Q-rings — Rotor’s take on oval rings and one of the Spanish brand’s flagship products — as well as regular round rings.
A highly modular design
One of the key highlights of the groupset is the intercompatibility between both road and mountain bike components.
With both Rotor’s UNO and 1x13 groupsets, at the lever end, you’re essentially just operating a hydraulic switch, with the indexing mechanism housed within the derailleur itself.
This arrangement meant that designing a shifter for road or mountain bikes is very simple (at least compared to a mechanical groupset, where different pull-ratios between different generations and groupsets complicates matters).
Both a mountain bike and road shifter will be available for the new 1x13 groupset. The road shifters will use the existing Rotor UNO shifters.
A full complement of discipline-specific cassettes and chainrings should mean that the groupset can be adapted to pretty much any use.
Does this mean a new freehub standard?
The new 13-speed cassette works with a regular Shimano HG-shaped freehub that has been ever-so-slightly extended and pushed inboard to work with the additional cog.
The limit on a HG-style freehub is usually 11t, so to accommodate the 10t cog, this now sits slightly outboard from the freehub, with a special lock ring developed to work with this setup.
While Rotor will only offer the freehub on its Rvolver hubs to start with, the freehub is an ‘open standard’, so other manufacturers are free to develop their own hubs with the new design.
What about the weight and price?
At the time of writing, we don’t have the claimed weights or pricing, but Rotor ensures us that these are on route.
How is it likely to perform?
A handful of BikeRadar testers have used Rotor’s UNO hydraulic groupset since it first launched back in 2016.
All have been impressed by the performance of the rear shifting on this first-generation group, but most have found the front derailleur to be a little less refined feeling and vague compared with a mechanical or Di2 equivalent.
Ditching the front mech makes the whole groupset seem more viable, particularly as the hydraulic actuation presents genuine advantages — compared to a mechanical groupset, we’ve found the closed system hydraulics to require next to no maintenance, and unlike an electronic groupset, it doesn’t require charging. In-line adjusters on the shifter’s hoses also permit the ability to customise the feeling or weight of shifts, which remains a unique feature.
Who is going to use this groupset?
If I’m to believe Rotor, the UNO groupset has seen uptake that surprised even Rotor, with the majority of buyers primarily driven by the desire to have something different to the majority of other cyclists.
It’s almost a given that the groupset is going to be expensive, but there have been plenty of rumblings that a number of other small manufacturers are well on the way to — or are at least considering — entering the groupset market. This suggests there is a real demand from the high-end market for something different from the big three.
From a racing side, if you’d asked me a few days ago, I would have speculated that we would maybe see Aqua Blue Sport — who are riding 3T’s 1x-specific Strada this season — using the new groupset, with the release of the Strada Due on Wednesday, that seemingly obvious collaboration now seems less likely.
What do you think of Rotor's new 1x13 groupset? Does it make the idea of 1x more compelling, or does adding yet another cog fill you with blind rage? As always, please leave your thoughts below.