TIME TO CHANGE

24 speeds from a single ring groupset - how does that work? The answer is: with Belgian brand Classified’s clever new hub gear. 

Pearson On And On Aero Gravel Bike Powershift Carbon Wheelset
Photo Credit - David Arthurs

Here at Pearson we’re always looking for the best new products to up your cycling experience. That’s why we’re proud to be one of the first UK brands to stock the Classified hub gear system, available in our own Hoopdriver carbon wheels and Classified’s own carbon wheelsets.

The set-up looks like a normal rear hub. But inside there’s a planetary gear system like that used in automatic gearboxes for cars and in multispeed hub gears for bikes like the Shimano Alfine and Rohloff hubs. But whereas those systems are heavy and complex and give you up to 14 speeds, the Classified hub weighs around the same as a conventional front derailleur system, uses an 11 or 12-speed cassette and switches between just two gear ratios.

Those ratios are similar to the ratios you’d get in a conventional two chainring system. Depending on the size of chainring you select, that can be any of these ratios:

Chainring size

Equivalent small chainring ratio

54

37

52

36

50

34

48

33

 

So the Classified system offers gearing to suit riders from out-and-out racers and time trialists through to super-compact gearing for gravel riders, including the popular compact and semi-compact ratios, just by swapping the chainring. It’s a real alternative to a front derailleur system and the Classified hub has a number of other advantages.

Shift under load

Pearson Classified Powershift Hub
Photo Credit - David Arthurs

A huge plus for Classified’s hub over a front derailleur is that you can shift under load. The planetary gears in the hub are continuously engaged and when you shift between ratios, a motor in the hub simply locks or unlocks them. The change occurs in just 150 milliseconds and can handle loads of up to 1000 watts, so there’s no need to ease off when you make a shift and no risk of losing a chain, unlike a conventional two ring chainset.

The shift is controlled via a wireless connection between a conventional electronic brake/shift lever and the Classified smart thru-axle. Classified also has a satellite shifter mechanism, which you can mount anywhere on the bars and use if you’re running a mechanical groupset. 

The signal to shift is mediated via a bar-end transmitter that’s mounted in the left bar end and uses Bluetooth Low Energy to communicate with the system’s smart thru-axle. As well as the electronics, the thru-axle houses the battery which powers the shifting mechanism. Classified says that It’s good for 10,000 shifts on a single charge, after which it’s rechargeable via a micro USB cable.

Efficient drivetrain

Classified says that its system is as efficient as a two ring set-up as well. 

In the higher ratio, there’s a 1:1 transfer to the hub and no lost power as the internal gears are locked. Switch to the lower ratios and Classified claims that there’s less than one per cent frictional loss in its planetary gear mechanism. But that’s offset by the lower friction in the chain when running over a larger chainring, which is due to the lower angular movement between the links.

Wide range with small jumps

Pearson Classified Powershift Carbon Wheelset

Classified’s system eliminates some of the negatives of single ring groupsets, like the large jumps between ratios and the need to run very wide range cassettes, which have a less mechanically efficient 9 or 10 tooth smallest sprocket and large, heavy largest ones. 

The Classified hub provides up to 451 per cent range between lowest and highest ratios, while keeping the cassette to a maximum size of 11-34. The chain is also put under less tension than is needed to handle the large difference in sprocket size in a wide range single ring system.

22- or 24-speed options

Classified has future-proofed its system by offering both 11 and 12 sprocket cassettes, so it’s compatible with the latest Shimano, SRAM and Campagnolo 12-speed groupsets as well as with older 11-speed systems. 

The cassette itself is unique to Classified and designed to fit over the oversized freehub body. Like the top spec SRAM Red cassette, it’s machined from a single piece of high strength steel, with the intricate machining resulting in a skeleton structure that’s lightweight, robust and durable.

Pearson Classified Powershift Hub

 There are plenty of different range options, with 11-speed cassettes available covering 11-27, 11-30, 11-32 and 11-34 and 12-speed cassettes with 11-28, 11-30, 11-32 and 11-34 ratios.

The system is compatible with single ring electronic and mechanical groupsets from Shimano and SRAM. That means that you benefit from the wide-narrow tooth profile of single chainring systems, which also helps with chain retention. Classified recommends that you use a single ring-specific clutched rear mech.

It’s designed to work with a bike frame with a 12mm x 142mm thru-axle - that’s pretty much every disc brake road bike out there. Since there are a range of nuances to thru-axle design, like different length threads and different thread pitches, as well as conical or flat interfaces to the dropouts, the Classified smart thru-axle ships with all the adapters needed. 

Other advantages of the Classified system

Weight-wise, Classified says that a bike equipped with its hub and 1x Shimano GRX Di2 gearing weighs within 10 grams of a bike with a traditional 2x11 GRX Di2 groupset and a DT Swiss 350 hub. Aerodynamics are improved too, as there’s less perturbation of the airflow, which is caused by the second chainring and the front mech in a two chainring groupset.

Classified’s system is also weatherproof and it’s easy to disassemble the hub body from the wheel with just a few standard tools, so you can potentially swap the hub between multiple wheelsets.

Take a look at Classified’s site for more information on its system, or watch this video from GCN to see what Si thinks of the system and how it feels to ride it.

Pearson or Classified wheel options

Here at Pearson, we are now offering the Classified system as an option on our Hoopdriver road and gravel wheels. You can opt to buy our road and gravel bikes set up with a single ring groupset and Classified shifting too as an alternative to a conventional single ring or double chainring groupset. 

Pearson Classified Powershift Carbon Wheelsets

Classified also sells its own carbon clincher disc brake road and gravel wheelsets, complete with the Powershift hub and shifting hardware, which we also stock. The gravel wheels are 30mm deep and 23mm wide internally, while the road wheels come in 35mm or 50mm depth and are 19mm wide internally. All include a front wheel built on either a DT Swiss or Hope hub.

SHOP CLASSIFIED CARBON WHEELSET & POWERSHIFT KIT

Authored By Paul Norman
Paul has been riding since he was a teenager - and that’s a long time ago now. He was into gravel before it was even invented, riding over the South Downs on his cyclocross bike. He’s been writing about bike tech for leading UK publications and websites for over six years, travelling throughout Europe covering bike launches and riding with some of the road racing greats.
Connect with Paul Norman

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