Introducing the Classified Powershift Hub

Classified Cycling is a Belgian company with one big idea - a two-speed geared hub to add gear range to a road bike or gravel bike. Maybe you can think of it as a high-tech version of the internally geared hubs your bike had where gears were activated by backpedaling slightly. More than anything though, Classified thinks of their geared hub as the replacement for a front derailleur.

Build Your Classified Powershift Drivetrain at Contender Bicycles

What Do You Need To Install a Classified Drivetrain?

There are, at a minimum, four things that you need: a Smart Handlebar Unit, a Powershift hub and hubshell, a Powershift cassette, and a Powershift Smart Thru Axle.

Classified uses a central brain called a Smart Handlebar Unit. It is not unlike Shimano does with their GRX Di2 groupset. In this case, the brain sits in a handlebar end. The handlebar unit, for all intents and purposes, is wireless and communicates directly with the Smart Thru Axle to shift between the standard gear and the lower reduction gear. It is designed to be controlled either by a Shimano Di2 11s shifter or via a satellite sprint shifter connected to the unit, with planned future compatibility with Shimano 12s and SRAM AXS. The Handlebar Unit is powered by a CR1632 battery and Classified claims battery life for a year or more. And because the system uses the ANT+ protocol, riders can connect their computers to the system to display which of the two gears they are in.

The Powershift hub is the essential piece to how the system works. In short, the hub features a set of planetary gears (like a car’s transmission) designed to use two gear ratios. One gear ratio can be thought of as the direct ratio, or what you would feel as if there was only a chainring and cassette cog. The other gear is the lower gear, which allows the hub itself to rotate less for every pedal rotation. As a result, the rider gets an easier set of gears without worrying about a front derailleur. 

The hub is held in place by a Classified hub shell, or the outer part of the hub that builds into a full wheel. Classified claims that makes wheels swaps easy; remove the rear wheel, pull off the inner hub with gears, and you can grab another wheel that uses a Classified hub shell. This is beneficial for those who use their bikes with two wheelsets as to avoid needing to pair a new hub to your axle and shifter.

Unlike a standard bicycle hub, the Classified hub has to use its own cassette and lockring. Much of this looks like it is due to the space required by the planetary gears, so instead of a traditional cassette from SRAM, Shimano, or Campagnolo, riders are locked into the brand’s array 11 or 12 speed cassettes. Sorry, Campagnolo Ekar fans, though we wouldn’t be surprised if there is a an Ekar option down the line.

Above are two charts. The top chart shows total gear range for some of our most popular gear ratios and how a Classified system compares. While SRAM RED eTap AXS 1x with a massive 10-52 Eagle cassette offers the most overall range, the jumps in between each gear can be massive; an average jump of 3.5t per gear and a colossal 10t jump between the 11th and 12th lowest gears. In comparison, Classified's largest 11-34t 12s cassette has an average tooth jump of just 2t per gear. That translates to smoother shifts between gears, less variation in your pedaling, and a smoother overall ride as well.

The second chart shows the difference in gear ratios between Classified's 'virtual' big ring and small ring and other 2x drivetrains. Classified's reduction gear is roughly equivalent to a 0.686:1 drop, similar to what one might find from many other standard 2x drivetrains. And while Shimano GRX Di2 might offer a slightly lover overall gear ratio, Classified Powershift has a much lower ratio than SRAM 2x. It goes without saying that the ratio is vastly lower than a 1x drivetrain without a Classified Powershift system as well.

Okay, all of these things make sense, but why does this need a specific thru axle? The Thru Axle is on the receiving end of communication from the Smart Handlebar Unit, and it is responsible for driving the electronic shifting within the Powershift hub. No Smart Thru Axle, no shifting. Simple as that. The thru axle unit itself looks like a quick-release lever, sticking out on the left side of the hub. It has a small LED light that lights up for every hub shift and is rechargeable via a micro-USB port. 

To note, thru axles come in different lengths, thread pitches, and curvatures, meaning just sourcing any Classified Smart Thru Axle is not enough to set it up on your bike. We’ve worked to make sure we have a variety of thru axles in stock as well as the small pieces to make it work, but it can be complicated if one tries to do it themselves.

Is My Bike Compatible With a Classified Hub System?

There are a few requirements that a bicycle needs to meet to be compatible with a Classified hub system. Want to know if your current bike or your dream bike is compatible with Classified? Let us know.

• The bicycle must use disc brakes with 142mm thru axles. No quick release skewers allowed here, and no Boost spacing allowed either.
• One can use either a mechanical or electronic groupset. Shimano Di2 11s shifters can be configured to shift the Classified hub; otherwise, the hub is controlled via a small satellite button mounted on the handlebar.
• The handlebar used must be Shimano Di2 compatible as the Smart Handlebar Unit fits in the same way as a Di2 bar end unit.
• Your existing crankset can carry over easily, though Classified recommends using a 40t or larger chainring with your 1x drivetrain.
• If you use your bike regularly on a trainer, you will have to remove the Classified Thru Axle. This means the hub loses its shifting ability in the trainer, leaving only the rear derailleur shiftable.

How Does It Feel?

We’ve watched the development of the Classified system from afar for quite a while. As much as we have come to appreciate the advent of 1x drivetrains for their simple functionality, the lack of smaller steps between gears means that those looking to go fast on gravel often have to rely on louder, more finicky 2x drivetrains or face big jumps between gears that can hurt your cadence rolling through chunky gravel roads. A Classified drivetrain, at least in theory, provides the small gear jumps of 2x with the chain retention and practicality of 1x.

One of the main reasons internally geared hubs aren’t on road bikes generally comes down to two things: efficiency and weight. Despite how much we talk about wanting to optimize drivetrain losses in our fast bikes, internally-geared hubs are almost always less efficient, draggier, and certainly heavier than derailleur-equipped drivetrain with equivalent range. Classified claims their hub is about 99% as efficient as a normal bicycle freehub system. Most people will only amount to a couple of watts here and there, or the difference between a clean drivetrain and a dirty one.

Classified claims that their system adds no extra weight when compared to a 2x drivetrain, with the additional claim that a Classified system with a 1x Shimano GRX Di2 electronic weighs about the same as a 2x GRX Di2 drivetrain. Our experiences with Classified drivetrains are limited to custom bike builds, so we don’t have much to compare to in regards to weight. But the bulk of the weight change come from the hub, and considering that Classified’s wheels are highly competitive on weight compared to other systems, we believe the claims.

How does a Classified hub compare to a front derailleur? In short, very favorably. Unlike a derailleur system that requires the chain to be in movement to shift between gears, the Classified hub will shift almost whenever, whether the rider is pedaling or not, and will do so smoothly at up to a claimed 1000 Watts. 

There’s no dropping a chain due to a front derailleur shift, no worrying about figuring out trim, and outside of hard efforts through the pedals, very little noise or buzzing. One other benefit? The hub doesn’t have a freewheeling sound, meaning coasting is near-silent. The only downside, outside of cost, is that riders need to know the specifics of their frames to make sure they have all the right parts to make this work. But that’s where we come in.

Conclusion

We think many people benefit from the greater simplicity of a 1x drivetrain, but those same people benefit from the wide range that comes with a 2x drivetrain. Classified’s system brings the two together in a system we think is legitimately useful, innovative technology. And while this will surely see a lot of benefits for 1x-only bikes, we even see this to be potentially huge technology for even fast road bikes. Faster than a front derailleur and quite a bit smoother too, the Classified Powershift hub is one of the most exciting bits of technology we’ve seen in years.

Want a Classified Powershift system for yourself, either for your current bike or as part of a custom build? We can make it happen; give us a call during business hours or send us an email any time to [email protected] to get started on your custom bike build.