Belgian company Classified present a 2-speed geared hub, aiming to replace the front derailleur. With the same ratios and range of conventional systems, the geared hub promises to revolutionise cycling by getting rid of your drivetrain’s weakest link. To see what it’s capable of, we put the Classified hub through its paces on the Ridley Kanzo Fast gravel bike!

Classified Cycling? Never heard of it? It’s unlikely you have since the Belgian company is yet to make a name for itself. For the past seven years, a team of bike-crazy tinkerers has been secretly working on a revolution for the bicycle market. The result is unlikely to please your front derailleur as it has simply been rationalised away. Wiped out and banished forever to the antiques room, where it will lead a shadowy existence in the sad company of triple chainrings and rim brakes. The replacement is by no means another 1×11, 1×12, 1×13 or even a 1×14 system, but something completely new and unprecedented: 1×22! Is this a hoax or a quantum leap in terms of drivetrain performance on the bike? What we can say for sure is that with their idea, the boys and girls from Classified Cycling could be the reason the production machines for derailleurs will soon land on the scrap heap …

What information can be found in this review?

I have a dream

The idea is as simple as it is ingenious: you move the function of the often inconsistent, wide tire restricting, visually unappealing front derailleur to the rear and hide it in the hub where it is nicely protected. Classified have integrated an electronically controlled transmission into the hub, which, identical to the front derailleur, shifts up and down between a ratio of 1:1 and 0.7:1 via a shifter on the handlebar. For comparison, conventional chainring combinations have the following gear ratios:

  • 53/39 corresponds 0.73:1
  • 52/36 corresponds 0.69:1
  • 50/34 corresponds 0.68:1
  • SRAM 50/37 corresponds 0.74:1
  • SRAM 48/35 corresponds 0.72:1
  • SRAM 46/33 corresponds 0.71:1

With the Classified system, the rear derailleur remains as it is and you only get rid of the front derailleur, which is the weakest link according to the Belgian company, so you’ll never drop a chain again and scratch your frame. In return, the Belgian brand promise more drivetrain efficiency, aerodynamic advantages, the option of wider rear tires (if the frame clearance allows), reliability and of course the most important thing in cycling: a clean and tidy looking bike!

The Classified components in detail

Classified Power Shift Hub

The hub contains Classified’s core technology: an electronically controlled planetary gear with two gear ratios, made up of a large number of cogs. In layman’s terms, it can be described as follows: the direct gear, i.e. the 1:1 ratio, the cogs of the transmission are locked, which means that the cassette and hub rotate at the same speed and one revolution of the cassette equals one revolution of the hub. In the 0.7:1 reduction, the forces of the cassette are passed on via the planetary gear, which means that the hub rotates 0.682 times with one revolution of the cassette, giving you a “lower” gear. The electricity required for shifting is supplied by the Classified Smart Thru Axle as the hub itself doesn’t contain a battery. According to the manufacturer, this should enable quick and uncomplicated wheel changes. Logically, the Power Shift Hub is exclusively compatible with the Smart Thru Axle and no other thru-axles.

Classified cassette

Due to the design of the system and the space required by the planetary gear, the Classified hub isn’t compatible with conventional cassettes. The specially developed 11-speed Classified cassette is available in four configurations: 11–27, 11–30, 11–32 and 11–34 t. This should accommodate most types of riders, allowing you to find the right setup for everything from competitive road cycling to relaxed gravel rides. In combination with the Power Shift Hub, you get a gear range of up to 451%. The Classified cassette is compatible with Shimano’s CN-HG601-11, CN-HG701-11 and CN-HG901-11 11-speed chains as well as KMC X11 and DLC11 chains.

Groupset Shimano GRX Di2 Classified 1×22 Shimano ULTEGRA Di2 2×11 SRAM RED eTap AXS 2×12 SRAM RED eTap AXS 1×12
Cassette 11–34T 11–42T 10–33T 10–50T
Crank 50–34T 46–33T
Cassette gear range 309 % 382 % 330 % 500 %
Total gear range 451 % 562 % 458 % 500 %

Classified handlebar unit

The handlebar assembly consists of a wireless transmitter that gets hidden inside a Shimano Di2 compatible handlebar that features a wiring port at the end of the bar. The transmitter can either be operated using a Shimano Di2 gear lever or satellite buttons. This makes it possible to also use the Classified system with SRAM, Campagnolo or mechanical groupsets. A 12-speed cassette is currently under development and will be available in the future for compatibility with 12-speed groupsets. The unit is powered by a CR1632 battery which, according to the manufacturer, should last for over a year and is easy to replace without having to re-wrap your handlebar.

Classified Smart Thru Axle

Classified’s proprietary Smart Thru Axle receives the wireless shifting signal from the handlebar unit. It drives the electronic shifting process in the hub by means of contactless energy transfer via an induction coil. The axle – currently only available in the 12×142 mm standard – gets charged via a micro-USB port and is claimed to last for more than three months or 10,000 shifting operations on a single charge as each shift only uses up one Watt of energy. Both the handlebar unit and the axle have LEDs that light up when you shift, the colour of which indicates the charge status of the battery. You can also check the charge status by pressing the status button on the handlebar transmitter or the axle. The system is ANT+ compatible, allowing you to connect your GPS computer and have it display the current gear you’re in.

Classified hub shell

The hub shell is easy to separate from the Power Shift Hub so that you can use several wheelsets in combination with a single system. Simply slide your selected wheelset over the Power Shift Hub – provided it’s built up around the Classified hub shell – and thereby adapt your bike to the respective terrain, it’s that simple. There is no need to adjust the bearing preload or pair the handlebar unit with the Smart Thru Axle for a second time. According to the manufacturer, the hub shells should soon be available on the Classified webshop, along with a matching front hub. However, changing the front hub would only be necessary for aesthetic reasons.

Which bikes are compatible with the Classified system?

As already mentioned, there are some requirements a bike has to meet to be compatible with the Classified system, which is currently only available to original equipment manufacturers.

  • Groupset both electronic and mechanical. Can be operated directly via a Shimano Di2 shifter, or via satellite buttons (Shimano mechanical, SRAM, Campagnolo).
  • Handlebar must have a port for the cables at the end of the handlebar and therefore be Shimano Di2 compatible.
  • Frame currently only suitable for bikes with a 12×142 mm rear axle, but should also be available for mountain bikes and time trial bikes in the future.
  • Wheels Regardless of the wheel size, the rear wheel must be built up around a Classified hub shell.
  • Crank compatible with all cranksets and crank or pedal-based power meters. The chainring must have at least 40 teeth; optimised for 40 t to 54 t.
  • Brake Disc or Centerlock-only

Speaking of compatibility: the Classified system doesn’t work with trainers that get clamped to the rear axle. In the case of trainers that have their own cassette, you’ll no longer be able to shift gears via the Classified system, leaving you only with the rear derailleur.

How much does the classified system weigh?

In contrast to other geared hubs, Classified claim that their system adds no extra weight to the bike and it should weight the same or even less than a traditional bike with an electronic 2×11 groupset, using DT Swiss’ 350 hub as a reference. Specifically, a bike with a Classified system and Shimano GRX Di2 groupset should weigh the same (+/- 10 g) as a bike with a Shimano GRX RX815 Di2 2×11 groupset.

The Classified system on test

We’ve seldom been as excited about the launch of a new product as we were before testing the Classified geared hub. Our expectations were high after seeing the presentation and one thing was certain: if the system performs as promised, it could be a real game-changer!

At first glance at the bike, a Ridley Kanzo Fast gravel bike, in this case, the Classified system is hardly visible. The Shimano Di2 shifters don’t have any modifications and the rear wheel and hub can hardly be distinguished from a conventional model. Only the non-drive side receiver on the thru-axle reveals that this is no ordinary bike with a 1×11 groupset.

The first shifts with the Classified hub were mindblowing, offering a completely new feeling of changing gears. Changing up or down is almost completely silent and done in the blink of an eye the moment you click the shifter. The system does its job without complaining even when it’s under strain, whether you’re winching yourself up a climb in a low gear or you’re accelerating in a high gear. The only time we managed to make the system emit a slight noise was when shifting down under load, as we’re used to with classic derailleurs. Other than that, the shifting is no way similar to that of a front derailleur! After having struggled with front derailleurs and dropped chains for years, being able to shift instantly and almost silently into the “virtual” small or large chainring is revolutionary! If you shift without pressing down on the pedals, you won’t even notice the shifting process. You can also shift gears while the bike is stationary when standing at a traffic light, for example. In that case, the shifting process is carried out as soon as you step back on the pedals.

The Classified cassette delivers a convincing shifting performance and is in no way inferior to its Japanese counterpart from Shimano. The chain is able to glide up and down the cassette smoothly and, unlike other third-party manufacturers, the Classified cassette gave us nothing to complain about. In keeping with the quiet operation of the hub, the silent freewheel also suits the concept. There is no buzzing to be heard and you can take in your surroundings without any distracting background noise. However, if you’ve previously used the sound of your freewheel as a way to warn pedestrians, you’ll probably have to get a real bell.

You’ll be able to couple your GPS computer with the Classified system via ANT+ if you want to see what gear you’re in. The battery, which is housed inside the thru-axle, can easily be charged via a micro USB port. We weren’t able to exhaust the battery’s capacity during our test, which is why the three-month runtime stated by the manufacturer seems plausible.

In terms of pedalling efficiency, Classified promise values close to 100%. Our test riders, who regularly test the best groupsets that money can buy, couldn’t find any differences in their comparisons. We couldn’t find any noticeable wear during our test either. However, we’d have to ride the Classified a couple of thousand kilometres more to be able to make a reliable statement on this.

Unfortunately, we sporadically struggled with a software problem during our test. When shifting several times in quick succession, the LED on the axle lit up permanently and we were no longer able to shift. In this case, we were forced to take a break to wait for the system to power down, thereafter we could get back on the bike and carry on as normal. According to Classified, they’re aware of the problem and they’ve been able to eliminate it so that production bikes shouldn’t have this software bug.

Our conclusion on the Classified system

Words like revolutionary or game-changing should be used sparingly, or they’ll quickly lose their meaning. However, the Classified hub blew us away during our time with it and it continues to do so. It has the potential to render the front derailleur useless on high-performance bikes. Shifting up and down is almost instantaneous and faster than with a front derailleur, it performs perfectly even while under strain and is significantly quieter than a front derailleur. The only thing clouding our impression slightly was the software bug. However, if this issue has been dealt with, riders and bike designers all over the world can look forward to bikes that no longer need a front derailleur!


  • immediate shifting
  • capable of shifting under load and when stationary
  • super quiet
  • makes it possible to have a clean looking bike and small gear steps
  • doesn't restrict rear tire clearance
  • more freedom for bike designers
  • less risk of dropping the chain


  • not easy to retrofit on an existing bike
  • issues on our test bike with the old software version

For more information about the Classified hub, visit

Words: Philipp Schwab Photos: Valentin Rühl, Philipp Schwab