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Video First Look: Rotor 1x13 – all you need to know about Rotor's latest hydraulic groupset

Dave looks at the benefits of 1x13 hydraulic, why you should want it, and what bits of your bike you'll need to replace to fit it

We’ve already covered the Rotor 1x13 hydraulic groupset but now we’ve had some time to chat with the engineers on the project, and learn a little bit more about the system. So here’s a closer look at the system, why they’ve designed it the way they have, and which bits of your bike you’ll need to swap out to run it.

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Why 1x13?

There’s been a lot of talk about single ring transmissions in road riding over the last few weeks. We’ve seen the launch of the new 3T Strada Due which has added double chainring compatibility to a bike that was designed for 1x; that means you can run the bike with any groupset (so long as it’s electronic), but in terms of aerodynamics it’s a retrograde step, as a 1x system cuts through the air more cleanly. So why the change? At least partly it’s in response to the Aqua Blue Sport team’s needs; an 11-speed cassette with a single ring doesn’t give the same range as a double unless you increase the gaps between the gears, and that means you sometimes fall out of your optimum cadence range.

A 2x11 system doesn’t have 22 gears. Well, okay, it does, but realistically you’re looking at 14 sequential gears, because you’re not going to be shifting up and down the rings at the front all the way through the middle of the cassette to get all the small steps. You’ll shift once from little ring to big, and that gives 14 ratios.

rotor_2_eurobike_show_2018-5.jpg

Rotor has been doing a lot of work looking at optimal cadence and speed, mining data from their professional athletes using their power meters. What they’ve discovered is that optimal cadence isn’t a rigid thing; instead it varies, with a narrower band in higher gear ratios and a wider spread as you get lower. The engineers showed us a lot of graphs, but the upshot is that with the correct 13-speed cassette you can cover all speeds, with the same spread of gears as a double, and keep the rider within the optimal cadence range the whole time. So there’s no downside, in terms of pedalling efficiency, to running 1x13 instead of 2x11. TO replace a 53/39 and 11-28 setup, you can run a 50T chainring and Rotor’s 10-36 cassette. For road riding Rotor is offering the 10-36 and a slightly wider ratio 10-39, which is more the equivalent of a compact double and a wider-range cassette. There’s a 10-46 which can be used for gravel or mountain biking, and a 10-52 for the widest range off-road.

 

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Will I need new wheels?

If you want to run 13 speeds at the rear, then you will. Rotor is using the standard open source spline pattern, the same as Shimano cassettes (except XTR), but it has been moved inboard by 3mm. That allows Rotor to use a new, two-part lockring and a 10-speed sprocket that sits outboard of the freehub. The cassettes are two-piece, with the bigger sprockets made from aluminium and the smaller ones from steel. The two bits are bolted together, but splines between the two sections transfer the torque. The cassette only contacts the splines near the outer edge of the freehub body, but the contact point is wide enough that there’s no danger of it digging into the alloy freehub. The cassettes are very light, with the 10-36 weighing just 240g. The 10-39 weighs 252g and the 10-46 is 273g.

The reduced dish of the wheel means that Rotor is only offering the new hub as a disc brake system, because they’re not convinced the final wheel would be stiff enough not to rub on rim brakes. Anyway, the Rotor Uno shift levers, which are repurposed for this new groupset (minus the left hand shift mechanism), are disc-only anyway. The new 13-speed hubs have a 2:1 spoke ratio on the rear (24 spokes with 16 on the drive side) to increase stiffness.

rotor_eurobike_show_2018-10.jpg

If you don’t want to buy new wheels then you can still run the new groupset, but only as a 12-speed system. The large sprockets are sufficiently big on all the cassettes that the biggest sprocket can be offset back towards the spokes, so in the same way that Shimano fitted their 11-speed mountain bike cassettes on to a 10-speed freehub, the 12-speed cassettes (with an 11-tooth smallest sprocket) fit onto a standard 11-speed road hub. A button on the rear mech switches from 13-speed to 12-speed operation. The chain, for both the 13-speed and 12-speed variants, is a standard 12-speed KMC chain. The sprockets use the same spacing as SRAM Eagle.

 

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Is the rear mech the same as Uno?

Well, it uses the same shifting technology, with a 3mm hydraulic hose. The indexing is all housed within the mech itself, so once the system is set up and bled, and correctly indexed, it shouldn’t ever move out of alignment. In that regard it’s similar to electronic groupsets. The hydraulic hose is indifferent to tortuous cable routing, so the route from the shifter to the rear mech should have no effect on shift performance.

The mech has been pretty radically designed, though. For a start it’s designed to work across all disciplines, so it needs to be tough enough to withstand the rigours of mountain biking. Gone is the open design of the Uno mech, with the new mech using a closed alloy body for better protection of the shifting mechanism from the elements, and from damage. The cage and parallelogram have been redesigned for the extra capacity needed; it’s just one cage length for all the different configurations. GIven that it has a 42T capacity for the 10-52 cassette, if you’re using the 10-36 cassette you should have no issues switching between chainrings if you need to.

Because it’s a single-ring system, and because it’s designed to be used off-road, Rotor has added a clutch system to the mech to keep the chain well-tensioned over rough terrain. There’s also a clever system that disengages the lower part of the cage to slacken the chain, making it easier to get a wheel in and out of the bike. A small button on the mech will dump the system into the highest gear, so there’s no need to click through all the ratios to get the mech in the best position to release the wheel.

The mech looks a lot chunkier than the Uno, so is the system a lot heavier? Well, Rotor was keen to point out that Uno was the lightest road groupset available, 150g lighter than Sram eTap. The new groupset is heavier, but in a 10-36 configuration it’s only heavier than Uno by about 30g, with the absence of the front mech offsetting the heavier rear mech and cassette. So, it’s still very light. And the 12-speed configuration is even lighter.

 

rotor_eurobike_show_2018-10.jpg

Is it aero?

Well, 1x systems are more aerodynamic because the lack of front mech and double chainring cleans up the airflow around the bottom bracket. By the time you get to the position of the rear mech – at the back of the bike behind the rider’s leg – aero gains are less of a concern, so the bigger and more angular rear mech is unlikely to make much difference. Rotor wasn’t pushing the aero credentials of the new system particularly, but it’s unlikely to worse than the other top-level groupsets.

 

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When will it be available?

Rotor is aiming to have the first systems available in the first quarter of 2019. The system it was showing at Eurobike looked pretty finished, albeit a bit rough around the edges. Like the Uno, Rotor will be producing the 1x13 system in their facility in Madrid.

 

Dave is a founding father of road.cc, having previously worked on Cycling Plus and What Mountain Bike magazines back in the day. He also writes about e-bikes for our sister publication ebiketips. He's won three mountain bike bog snorkelling World Championships, and races at the back of the third cats.

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16 comments

Avatar
mattsccm | 5 years ago
2 likes

Chainline? Its poor on a 5 speed let alone 11. A chain is designed to run straighty. As any engineer who deosn't have a vested interest otherwise.

A front mech is possibly the most idiot proof and robust moving part on a bike. No need to have a great long mech dangling in the debris when you can tuck something out of the way.

Simple? Why dumb everything down for idiots.

Watts. Yeah right. Compared with everything else? Haha.

Cadence. I do wonder if they found eople who didn't suit their needs and tried it?

Its a gimick. now a triple and 13 at the back thus giving nice close ratios might be fun but those gaps are awful.

Maybe a MTBer who know nothing about efficient pedalling might like it but those of use brought up on tight, straight through blocks are rather more aware of this.

Hydro? Brilliant.

Avatar
Blake Goodwin | 5 years ago
0 likes

I would think one of the only remaining questions as we approach 1x13 status, is the effect on chainline. All other considerations seem to be subjective preferences, and this is an evolution towards the better - unless that chain is cranked extremely hard to the left or the right...

Avatar
imajez | 6 years ago
1 like

 "...you’re not going to be shifting up and down the rings at the front all the way through the middle of the cassette to get all the small steps. You’ll shift once from little ring to big, and that gives 14 ratios."

I often double shift to get the inbetween gears. It's dead easy to do, so why wouldn't you. Those inbetwen gears can make the difference bewteen getting a nice comfy cadence or not. Plus as janusz0 mentioned above, if you have electronic shifting, the gears can do exactly that for you anyway.

Avatar
dave atkinson replied to imajez | 6 years ago
1 like

imajez wrote:

 "...you’re not going to be shifting up and down the rings at the front all the way through the middle of the cassette to get all the small steps. You’ll shift once from little ring to big, and that gives 14 ratios."

I often double shift to get the inbetween gears. It's dead easy to do, so why wouldn't you. Those inbetwen gears can make the difference bewteen getting a nice comfy cadence or not. Plus as janusz0 mentioned above, if you have electronic shifting, the gears can do exactly that for you anyway.

i double shift at the point where i switch between chainrings, as i'm sure most people do. especially with a compact cassette, that's necessary and it's where the 14 speeds thing comes from. you use the big ring, drop down to small and 2/3 cogs at the back.

what i don't do is shift down to the smaller chainring and drop a couple of cogs, then shift up a chainring and a cog, then back down again and two, etc and so on, to make use of all the ratios. do people actually do that?

electronic shifting does offer the opportunity to do that. but given that your efficiency doesn't suffer so long as you're in your optimal cadence range, i'm not sure why it would help unless your optimal range is *really* narrow.

Avatar
janusz0 | 6 years ago
2 likes

Quote from Dave: "...you’re not going to be shifting up and down the rings at the front all the way through the middle of the cassette to get all the small steps. You’ll shift once from little ring to big, and that gives 14 ratios."

Errm, don't electronic shifters have the potential to do exactly that?  I understood that electronic shifters can cope with simultaneously alternating the chainrings as you shift up and down the cassette, thus giving you more ratios between highest and lowest gears if the chainring and casette steps are chosen carefully.

Aside from that I have to say "Go Rotor Go!"  I'm excited to be going back to the days when there were rather more than three major component manufacturers to choose from.

Avatar
RobD | 6 years ago
0 likes

I like it, it's a pretty smart set up, and I can see the attraction of hydraulic shifting, I guess it's a set and forget system, once it's working it should be pretty low maintenance for a long time.  A 1x13 setup would work pretty well for a lot of the cycling I do, I have no intention of racing,  and this would be ideal for going out for a few hours riding (it's not super hilly round here, although the ones there are are steep so a 'bail out' style gear would be handy).

Avatar
il sole | 6 years ago
1 like

Will I need new wheels?

If you want to run 13 speeds at the rear, then you will.

hhmmm, surely this will only ever be an OEM item - who's going to want to replace their standard groupset with a new one that requires new wheels?? so instead of a £2k outlay, you're looking at £3.5k...

I'd rather just spend that £3.5k on a 12 speed super record EPS... ( or am i defeating my arguement...?) ho hum!!!

Avatar
fukawitribe replied to il sole | 6 years ago
0 likes

il sole wrote:

Will I need new wheels?

If you want to run 13 speeds at the rear, then you will.

hhmmm, surely this will only ever be an OEM item - who's going to want to replace their standard groupset with a new one that requires new wheels?? so instead of a £2k outlay, you're looking at £3.5k...

I'd rather just spend that £3.5k on a 12 speed super record EPS... ( or am i defeating my arguement...?) ho hum!!!

You could run it in 12-speed mode and a 12-speed cassette (e.g. SunRace) on your existing wheels, but that's rather missing the point of it I guess..

Avatar
jonnystv | 6 years ago
1 like

Surely getting rid of the front derailleur is no bad thing. The cyce racing world has been innovating and simplifying since the get go:

The following quickly found online (bikeraceinfo.com) so can't vouch for its veracity:

"Before derailleurs came into use racers had double-sided rear hubs with up to two cogs on each side of the hub. Changing gears meant stopping and removing the rear wheel and flipping it around to use a different sized cog. Deciding when to perform this operation was an important part of early racing tactics.

The Tour forbade the use of derailleurs until 1937. But unlike the Tour, the Giro d'Italia allowed their use. The Vittoria system made by the Nieddù brothers, Tommaso and Amadeo, was the gear of choice among the Italian pros. Alfredo Binda had used the Vittoria system when he won the world championship in Rome in the fall of 1932. That success resulted in many pros mounting the system on their bikes for the 1933 season."

Is the new Rotor 1x13 system not just another step towards a more efficient and simple transmission system?

Not many people may buy this particulr system but when SRAM, then Shimano (and eventually Campagnolo) start selling it we'll wonder what we did witout it.

Probably.

Avatar
Stef Marazzi | 6 years ago
1 like

I really don't think they are going to sell many of these. I think cyclists are too savvy these days to fall for it. They must have spent a bomb on the R&D but I can't imagine they will get their money back, could be the downfall of Rotor I reckon.

 

Avatar
don simon fbpe | 6 years ago
0 likes

But Yorkshire wallet, I'm not so sure that it's your luddite side that preventing you from adopting new technologies, Yorkshire wallet. What do you think Yorkshire wallet?

I mean, when you think about it Yorkshire wallet, £6k for a bike is a lot of money, isn't it, Yorkshire wallet?

Avatar
Yorkshire wallet | 6 years ago
6 likes

The more miles I'm doing the more of luddite I'm becoming and thinking do we really need all this stuff?

Example this weekend. A mate did some organised ride in Wales that went up 'the tumble'. Blokes on £6k bikes walking it apparently. Lot of good their fancy electronic gears did them.  If only they'd have a 1x13 system. 

Avatar
Jimthebikeguy.com | 6 years ago
1 like

I think this is brill and i totally get the rationale behind it. Love it or loathe it, this is what shimano, campag and sram are all doing too, because it makes total sense.

Avatar
Woldsman | 6 years ago
2 likes

I may well be shot down by the Futurists, but really? Aero gains of one chainring on a gravel bike? A bike made to ride on actual GRAVEL for pity’s sake? 

“Rotor is aiming to have the first systems available in the first quarter of 2019”

This fuddy duddy reckons a launch on the following day would be more apposite. 

 

Avatar
fukawitribe replied to Woldsman | 6 years ago
1 like

Woldsman wrote:

I may well be shot down by the Futurists, but really? Aero gains of one chainring on a gravel bike? A bike made to ride on actual GRAVEL for pity’s sake? 

There's nothing gravel specific about the groupsets, nothing much activity specific at all really beyond the shifter type and which gear range might be more appropriate. 3T reckoned on about 8W difference between the Strada with/without the front mech and second chainring, so if you're into your TTs and fancied something different then why not eh ?

Avatar
Woldsman replied to fukawitribe | 6 years ago
3 likes

fukawitribe wrote:

Woldsman wrote:

I may well be shot down by the Futurists, but really? Aero gains of one chainring on a gravel bike? A bike made to ride on actual GRAVEL for pity’s sake? 

There's nothing gravel specific about the groupsets, nothing much activity specific at all really beyond the shifter type and which gear range might be more appropriate. 3T reckoned on about 8W difference between the Strada with/without the front mech and second chainring, so if you're into your TTs and fancied something different then why not eh ?

Fair enough. It’s clearly not my thing, so best of luck to Rotor and those that adopt this stuff. 

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