Review: Rotor's 13-Speed Hydraulic Drivetrain
We’ve seen Rotor's drivetrain show up in prototype form at various tradeshows in recent years. And finally, after a bit of a wait, I managed to get my hands on the production version to see how it stacks up against established offerings.
The group was built around 12-speed spacing, but the derailleur works with 12 or 13-speed configurations via a limit screw adjustment. However, you'll need to use Rotor's proprietary hub to get those 13 cogs. Rotor sells the drivetrain as a shifter, derailleur, cassette, along with their cranks and a hub. The 13-speed hub is backward compatible with 11 and 12-speed HG cassettes, and both the 12 and 13-speed groups use a standard KMC style 12-speed chain. Got all that?
The group was built around 12-speed spacing, but the derailleur works with 12 or 13-speed configurations via a limit screw adjustment. However, you'll need to use Rotor's proprietary hub to get those 13 cogs. Rotor sells the drivetrain as a shifter, derailleur, cassette, along with their cranks and a hub. The 13-speed hub is backward compatible with 11 and 12-speed HG cassettes, and both the 12 and 13-speed groups use a standard KMC style 12-speed chain. Got all that?
Rotor 1x13 Hydraulic Details
• 13-speed
• Hydraulic system
• Adjustable lever feel
• 10-52 tooth cassette
• Weight: 435-grams (derailleur / shifter / hose), 331-grams (cassette)
• MSRP: Base group w/ cranks & hubs: $1,800, shifter / derailleur: $999, 13s cassette: $415, 13s rear hub: $344
• www.rotorbike.com
• 13-speed
• Hydraulic system
• Adjustable lever feel
• 10-52 tooth cassette
• Weight: 435-grams (derailleur / shifter / hose), 331-grams (cassette)
• MSRP: Base group w/ cranks & hubs: $1,800, shifter / derailleur: $999, 13s cassette: $415, 13s rear hub: $344
• www.rotorbike.com
A 12-speed hydraulic group with a shifter, derailleur, chain, cranks, chainring, and 12-speed cassette sells for $1,400. The 13-speed group with front and rear hubs sells for $1,800, and the 13-speed group with Rotor's 2INpower cranks sells for $2,600. It's also possible to purchase items individually if, for instance, you don't need new cranks to go along with your fancy 13-speed drivetrain.
Why hydraulic? According to Rotor, they chose this type of closed system for its purported consistency and longevity...as long as it doesn’t spring a leak. Since there's no heat generated in a shift, the bleed interval can be, according to them, virtually indefinite. It also eliminates concerns about contamination, friction, and cable stretch. Additionally, the patent landscape was a little less cluttered and allowed Rotor more creative freedom to explore what they felt was the best way to make a shifter and derailleur.
Smoothly machined thumb lever.
The system is nearly fully closed, keeping out unwanted trail critters and debris.
Shifter
Rotor's hydraulic shifter has a removable second paddle, so riders can have a second position for shifting while riding with a different hand position on the bar. In practice, some riders may find it cumbersome, especially for riders used to the Shimano two-lever system, so there is the option of removing it. My test kit came with the lever removed, but the second paddle is still included in the groupset should you want it.
The shifter is much more basic than a mechanical shifter. It is merely a lever with a pin that pushes an actuator to drive fluid to the derailleur, which handles all shifting and indexing duties. Rotor's team claims that moving the indexing to the derailleur itself cuts down on the bulk and complexity of the lever and its replacement cost should you damage it in a crash. The lever itself works with MatchMaker style mounts and, like many MatchMaker style components, has two mounting holes, one more inboard than the other. Other than that, there's a bleed port on the lever just as there is on a brake for bleeding the system, with the other port being on the derailleur. The paddle for the lever is broad and smoothly machined.
A short push of the lever enables the derailleur to click into a harder gear. A longer push, on the other hand, shifts the derailleur into an easier gear. If you've ever ridden road bikes with a SRAM drivetrain, the action and feel are quite similar to that of the DoubleTap system they utilize. Check out the video below to see the Rotor shifter in action.
It doesn't get much more straightforward than this, lever pushes actuator, which forces fluid through the line.
Derailleur & Cassette
The derailleur for the system is the same for Rotor's 12 and 13-speed groups. Indexing is managed in the derailleur, which is a closed system to keep things safe from the elements. All of the adjusting for the system also takes place here. There is a button on the outside of the derailleur that allows it to "go to origin," dropping the chain down to the small cog for easy wheel changes. Additionally, there is an upper and lower limit adjustment. With the indexing residing in the derailleur, if a rider breaks a line on the trail, the derailleur can be moved into a desirable gear by hand. It will stay there, hydraulic line or not.
The large knurled adjustment on the derailleur is designed so that the limit can be adjusted by hand. For b-tension, there is a stepped b-limit screw that is intended to correspond to various cassette sizes since the derailleur can also work with a road/gravel shifter and, therefore, a much smaller cassette if desired. The barrel adjuster where the cable feeds in controls the lever feel to give more or less feedback from the indexing, allowing for a more firm or softer click when actuated.
The cassette is machined out of steel and aluminum to keep weight down and provide durability in the smaller cogs. The cassette comes in several tooth options in both 12 and 13-speed, with the 10-52 tooth option delivering the widest range. The 13-speed cassette uses Rotor's 13-speed hub and will not fit on a standard 12-speed HG freehub.
The derailleur is compatible with most other 12-speed cassettes, and it's the same derailleur used in Rotor's road system. This makes the shifter and derailleur pretty darn compatible as a system when it comes down to it.
13 gears on a 10-52 tooth cassette that weighs in at a very light 331 grams
The feel of the lever is adjusted at the derailleur with this barrel adjuster.
The b-limit screw utilizes a stepped retainer with a screw that holds it in place. Rotor claims this allows the derailleur to accommodate a broad range of cassettes.
How does it Compare?
In looking at other high-end drivetrains, Rotor wins the battle for the number of gears, with 13. The gearing profile is also slightly different from both Shimano and SRAM's wide-range systems, which could appeal to some riders. If we break things down into dollars, the Rotor drivetrain, consisting of the shifter, derailleur, and cassette, costs $1,414 when bought a la carte and weighs 766g. Lighter than SRAM's XX1 Eagle, Eagle AXS, and Shimano's XTR groups when you factor in a gear cable's weight. It's the highest price per gram at $1.85 per gram, nearly a dollar more than Shimano's XTR, which is $0.94 per gram. That extra gear is expensive but, at $108.77 per gear, it's still less than the $112.42 that SRAM's electronic AXS group goes for.
Installation
Installing the hydraulic drivetrain was surprisingly straightforward. Despite some initial hesitation, cutting the line and bleeding the system was a simple process, no different than bleeding a hydraulic brake. Set the limits, b-tension, lever feel, and you're on your way. In all, after doing it once, I could set up the system nearly as fast as installing a cable fed derailleur and bleeding a brake if I had to do it again.
While the installation was simple, the included instructions were not very helpful. It took a call to Rotor to understand how to make everything work as it should. The process is simple, but the manual was lacking. The instructional videos on Rotor's website are more geared towards the road system. This was confusing and not confidence-inspiring. While the instructions do carry over to the mountain drivetrain, I needed some reassurance.
The adjustment barrel at the end of the derailleur is used to change the feel of the lever. Twisting it in makes the shifter more firm and indexed while dialing it out creates a much lighter action. While bleeding the system, the dial should remain centered, according to the instructions.
The limit screws were easy to adjust. However, the knurled dial, which is made to be "tool-free," according to Rotor, wasn't always easy to move and it took using a T-30 to adjust it, a tool not very common on most multi-tools.
Performance
The system takes some getting used to, but it became more intuitive over the test period. Only when the barrel adjuster on the derailleur was fully dialed into the firmest setting, where the shifter's click is most prevalent, could I consistently and successfully shift how I wanted. However, I would still occasionally find myself missing a shift here and there. The ergonomics of the lever feel nice, but there's a lot of throw required to push the lever in. The shifter works similar to SRAM's double-tap road bike shifting system, where a small click/short shift drops down a gear, and a larger click/long shift goes back up.
Even with the shifter as firm as it goes, the feeling is sort of vague and takes a very long throw. This led to some rough shifts at times when I didn't push quite far enough. The inability to shift more than one gear at once, coupled with the shifter's long throw, makes for quite the thumb workout. Miss a shift and, at times, the chain would want to jump, usually down a large span of gears, but it would quickly find its way back to where it was supposed to go with another push. The only time this presented an issue was in slower, more technical terrain where that easier gear was crucial in cleaning a line on a climb.
The derailleur, which houses all of the shifting mechanisms in addition to standard derailleur duty, worked exactly as it should throughout the test period. The amount of tension on the cage felt a bit low at times, especially in rough terrain, as there was more noise and more chain slap than I'm used to with standard S products. That aside, everything held together through many miles on the trail and at the bike park, often in wet conditions. Even with frequent cleanings and hosings, nothing required extra maintenance or a bit of tuning up in a time I would typically replace a gear cable.
The 10-52 tooth spread, which has now been matched by SRAM's new cassettes, provided plenty of range for steep climbs and fast descents. The jumps between gears are smaller than with a 12-speed cassette. It never felt as if I was over or underpowered - it was easy to find a comfortable spot with the gearing.
Pros
+ Lightweight
+ Low maintenance
+ 13-speeds, small gear jumps
Cons
- Shifting is vague
- Proprietary hub required for 13-speed cassette
- Still not quite as smooth as high-end SRAM or Shimano
Pinkbike's Take
 | It's fantastic to see brands pushing boundaries and bringing new products to market. Rotor's hydraulic drivetrain is an excellent example of precisely that. The overall system works well, but at this price point, it should be outstanding. The shifting is accurate, and the hydraulic mechanism creates a system that requires minimal maintenance. However, it feels vaguer than it should, and it still isn't as smooth as SRAM's XX1 or Shimano's XTR drivetrains. The proprietary hub doesn't add any points either, as its engagement is fairly low compared to many other high-end offerings out there - something someone dropping serious money on a drivetrain is likely also looking for. |
Author Info:
Clarifications- teams do not choose to not run disc brake bikes because of tuning issues or any safety concerns, its because it takes ages to take out a thru axle and replace a wheel in the event of a flat, and it can be very costly to lose this time depending on the situation of the race. Perfect examples of this at the Giro today, where teams were abandoning doing wheel changes because it was quicker to just change a whole bike. It was taking mechanics like 30 seconds to change a disc wheel, even with preset electronic torque wrenches to get the thru axle in quickly. Some teams choose against disc bikes (Jumbo visma most notably) just based on this concern.
As an aside can we stop acting like discs are a concern for cutting people in road race crashes? this has been pretty thoroughly debunked, and the road bike racers no longer believe this is a concern. This idea came from a crash a few years ago where a rider claimed to be cut by a disc, but it later turned out to be a chainring. There are ample videos of people trying to cut themselves or pieces of meat with disc rotors at 100+ RPM and not being successful. Road racers have been racing with discs for many years and crashing all the time without issues. The idea of disc rotors being a danger is a non-issue
I bet this is more to do with brake drag after a quick wheel change.
Troubled spirits would say it is also to charge the internal battery...
SRAM: "wireless dropper!"
Fox: "live valve!"
Rotor: "hold my Rioja!"
Then again most people who buy this probably are doing all their own work so its a moot point.
I do like the cleaner handlebar setup, and the electric bits are tucked up and safe from harm. So I've got that going for me. :-)
Move it to the more frequently damaged derailleur instead. Makes sense
Obviously we all ride different, and presumably crash different. I'd be interested in a poll.
13 speeds and indexing on the derailleur, what's not to hate?
Have probably only broken one shifter in 10yrs tho
1- an easy gear but not piss easy so you know you have a fall back for the really hard stuff
2- the fall back
3- the playing around gear pretending you’re a bmxer
4- a gear for cranking
5- a gear for cranking real hard
*1 and 2 would obviously be switched places on the actually cassette
I have a 10-51 Slx with XT shifter and most of the time up shift two gears with it. It’s a bit much with a 2 gear gap but a gear and a half would be an ideal gap for my non-racing, non-stravaing, non-caring, 29+ steel hardtailing self.
11-42 cassette = 11-13-15-18-21-24-28-32-37-42
11-46 cassette = 11-13-15-18-21-24-28-32-37-46
So.. here you're obliged to use the 42 and the range remains small
Smaller more subtle cassette, short cage mech that isn't going to flap around or get snagged, shorter chain, overall lighter weight and if you (really) need to pedal up steep hills, just stand the f**k up and pedal slowly.
That said, when down shifting I usually down shift two at a time. So the 5 speed seems appropriate. But I would say I up shift 1 at a time to keep a low cadence. So that is a ding against 5 speed. The other thing is you need the right 5 speeds for a given trail. With 9 or 10 speeds, you should be able to find that sweet spot on any given trail. With 5 you are going to be compromised on most trails.
Personally, I really like the spacing on the Box 9-speed cassettes over the Microshift (they have the 37 to 46 jump) but the Microshift are like half the price or less. I don't need close 11-13-15 on trails. I basically never use those. It could probably go 12-16 and give me more middle range and more easy gears to choose from.
My old Raleigh road bike with a 2x5 drivetrain is pretty much what you're describing, lol
I eat a lot of chocolate. But at 65Kg and a high w/Kg, it isn't because I am weak. I just climb and descend big mountains.
Let me stop you right there. If I pay $1400 for a for a shifter there is no way in hell that it should feel "vague." I'm all for innovation, but this is another classic example of the MTB industry spoon feeding us something we don't want. On a road bike, where I'm less likely to shave my derailleur off the bike and grenade, sure! Hydraulic shift all you want. Don't make things complicated just for the sake of being different. Simple solutions are elegant and I'll always appreciate them.
Yes, along with BB30, Super Boost 157, and 28.99 spindles. A big F#CK YOU to all the over- innovators.
If this was SRAM or Shimano, introducing hydro shifters and phasing everything else out, then okay.
Rotor is a small player in comparison, like you said, not many people will get on board, but it's out there.
I don't know why even mention the price, this isn't for a conventional everyday rider, if course it won't compete on price or performance...yet.
How expensive were early carbon bikes, heck, how expensive (and shitty) were early hydraulic brakes, or suspension of any kind.
Better technology doesn't just magically appear, it's a product of iterations over years...I don't have to explain this
Maybe, version 2, 3 will be cheaper and better performing?
Here’s a thought experiment-
Imagine you were a relatively small components brand, how would you approach the issue?
You want to enter the drivetrain market, it isn’t your key component but you want to diversify. Being a smaller brand r&d time and resources are limited.
I’ll tell you how I would after.
This is no argument, I’m just curious about how you think.
I think to start to make components or pieces that improve existing tech would be an excellent starting point. Get your brand out there and make it known that you are producing quality parts. The Wolf Tooth conversion kit for the reverb comes to mind. In terms of the drive train market, perhaps that proverbial foot in the door could look something like a self setting b limit screw. Why? Because maybe you have a bike with adjustable travel bike and you want to make sure that the b limit is properly set for all geo configurations. Ridiculous, I know but I'm trying to come up with an industry revolutionizing idea on the fly here.
But I think you get my point. Rather than jumping in with both feet, test the waters, make some small parts that make existing parts better, and go from there. Obviously this is all easier said than done, but I'd like to think that's a logical progression.
What would your approach be?
Living somewhere where it gets proper cold, mechanical brakes (with sealed housing) provide better winter performance as they are not subject to seals hardening in the cold. My commuter and fat bike stop with TRP's Spyre and Spike respectively, but all of the rest of my bikes are hydro for braking (with the exception of a couple older roadies).
No?
Here we present you a hydraulic drivetrain!
Already looking forward to:" Sry I can't ride today, my derailleur is sagging, I need to bleed it first"
"Sry I can't ride, I shifted so fast, I got shifting-fade"
Check this out youtu.be/WvKxdd6mnVA?t=205
from the last round of team videos.
If it wasn't a fragile and fiddly component they wouldn't have to replace it every time. So it certainly ain't perfect.
The only real replacement for cables is IMO, AXS.
@markg1150: Indeed I am.
In contrast, you can tie your brake cable into a knot and as long as the fluid can go through you will stop.
Of course vibrations and any bit of miss-alignment are part of if, and you have a point, if a new hanger doesn't do it reliably for me it could as well be the frame. I'll check the eyelet and the rest next time it goes out of tune
Good luck. I’ve been in a similar situation and it was incredibly frustrating. So frustrating that I ended up getting a Di2 to solve once and for all. Butter smooth now every time. The only problem is I now have cable(less) envy towards AXS.
In contrast, as you said, that skinny hydraulic hose on this thing could go thtough some pretty tight bending and unbending and not care, and would actually make for a slick super stealth routing, perhaps through the bars and stem.
Anyway, we'll see where this goes, could be nowhere or it could become the new normal in a handful of years and versions, just like many other things we take for granted.
@Jmorgue: Haha, I'll try Shimano next and see how it goes. Cheers!
Peace out
Guys, I've replaced the whole drivetrain.
Shifting is as expected - like clockwork...until I bang the mech out of shape again
Cheers!
That is entirely unnecessary with a hydraulic line, and they missed an opportunity to tuck it neatly away, so you don’t worry about ripping it out. Foolish decision, considering that is a weak link.
Cheers
Why would you wanna attach a 500$ piece of tech to the place where it gets banged the most?
Maybe for roadies...
I love Shimano XT 12sp, works well, durable, cheap.
If I want to be different I'll get a tattoo.
As an old guy, pre tat gen, I fortunately never got a tattoo, though I have plenty of scars
"which is a closed system to keep things safe from the elements"
I think there is some confusion on what a "closed" system means. All our modern hydraulic brakes are closed off to the elements, but they use an "open" system to allow the reservoir to add fluid into the system as the pads wear and the system capacity increases. Early brakes used a "closed" system with no reservoir where pad wear was handled by manually adding fluid to the system. But even a "closed" system still has (imperfect) seals that can allow water and other contaminants in. This system likely has fewer and smaller sealed surface area, which reduces the potential for contamination, but the fact that it is "closed" alone does not make it more resilient to contamination.
Ah yes, brings back memories of Gillete vs. Shick from the golden age...
How many marketing exec @ SRAM, Shimano and now Rotor are thinking this:
www.theonion.com/f*ck-everything-were-doing-five-blades-1819584036
9 speeds is enough but no clutch.
The way forward is less teeth on the front, and less on the back.
The industry forgets that these are mountain bikes used by some people for climbing mountains, not trying to go faster on pavement.
In other words: Its only almost useable when made to feel like existing less expensive systems.
FAIL.
All you needed to say right there other than what's the point?
At the unbelievably stupid premium of 1400.00, 1800.00 and 2600.00 this should be better hands down, no if ands or buts. being completely different all of the tech info should have been ready before releasing it. Why am I not surprised by this from an over priced boutique niche company? Surely it must have Ceramic Speed pullies right?
Stupid is as stupid does for anyone buying into this ridiculous over priced shit.
[Reply]
It really needs to be a pawl and ratchet, and it really needs to have some sort of spring to have the derailleur lean towards one side of the ratchet. (I don't know the mechanism of this one). This was the failing with the Acros system.
That makes no sense at all. Surely the hose should enter at an acute angle straight into the Derailleur body, tucked away from danger.
If you going to radically change the design of something, the point is to start with a clean sheet and free yourself of the constraints/weaknesses of the existing products.
Google "Box Two Prime 9" if you want to try your luck but it's not a budget drive train even though it's 9 speed.
Also the clamping on the SRAM GX-derailleur as well as how the cable turns around the wheel is an engineering-crime and a serviceing nightmare. *fullstop
Therefore a very interesting concept imo.
I'm only concerned about the barrel adjuster being the most exploited part on the bike, especially beeing on the rearend.
I don't care if the trigger is heavy, so moving the weight to the derailleur is not good...
How can you even judge a product if you can't even install it properly?
In all seriousness, I am old enough to remember when there were other attempts at hydraulic rear derailleurs in the 90s. There is only a very small niche market for them. Maybe fat bike riders? Realistically, wireless shifting is far superior for most riders and it just needs an arms race between sramano for it to become commonplace and accessible.
Yes. I believe we have.