Gear hub Powershift from Classified

Classified Powershift Hub: Ready for a Mix of Its Own?

Update 12th February 2021

Now there is also a first manufacturer from Germany that incorporates the Classified drive on one of its bikes. Today, the online retailer Rose Bikes presented a corresponding version of its gravel bike Backroad. You can now purchase such a bike under the name “Backroad x Classified”. Assuming you have the necessary 5,299 euros to spare.

Original post 10th February 2021

Belgium is considered one of the world’s strongholds of cycling and cycling culture in general. Many inhabitants travel by bike. There are at least as many legendary riders as there are bicycle races. Innovations around the bicycle have come and continue to come from this small country. Classified could soon join the ranks. The manufacturer from Turnhout, near Antwerp, is yet a rather blank slate. Yet. With Powershift hub, that could change quickly. The concept translates the combination of a gearbox and a derailleur system into the here and now.

1. The best of both worlds
2. Wide range, small step size
3. Inconspicuous and pretty nimble
4. Minimal extra weight
5. Everything runs smoothly
6. Test ride will be difficult
7. Closed event
8. Future rosy or bumpy?

Powershift hub consists of a shifting unit, a gear hub for the rear wheel and purpose-built cassettes. The intention of the system is relatively simple: it transforms a derailleur with only one chainring into a 2x drive. For example, eleven gears become 22 gears with one click. The gearbox in the rear wheel gives you a second chainring, so to speak, while the number of sprockets remains unchanged.

1. The best of both worlds

In itself, this idea is an attempt to combine the advantages of a 1x drivetrain with those of a 2x drivetrain. After all, it is not without reason that the big players on the market, Shimano, Sram and Campagnolo, have pulled the minimalist variant with only one chainring and a choice of ten, eleven or twelve sprockets for mountain bikes, road bikes, trekking bikes, etc. out of the hat. Better aerodynamics, fewer components, less weight and less wear have been valid arguments and still are.

However, certain disadvantages cannot be denied. Such shifting systems have differences in the gradation between the individual gears, which some find too large. In addition, the maximum limit of twelve gears is not a choice that suits everyone in all riding situations. Furthermore, as research has shown, riding on the smaller chainring unintentionally exerts greater axial forces on the chain and the bearings of the crank and hub.

The larger the chainring, the smaller these forces are. At the same time, efficiency increases during pedalling. When using a derailleur system with two chainrings, one of them is always relatively large. And together with the smaller second chainring, the step sizes are also reduced. The price for this are the problems already mentioned with regard to wear, weight, possible defects and mis-shifting. Being able to enjoy only the advantages of both variants sounds appealing in any case.

2. Wide range, small step size

Classified hides the aforementioned second chainring in the rear hub of the Powershift hub. At least metaphorically speaking. In fact, it is a planetary gear integrated there that realises two gears. The first has a ratio of 1:1, the second has a ratio of 0.686:1. In practice, this development ensures that your permanently installed chainring will be 0.686 smaller. For example, if you have a 54t chainring, the gear ratio after shifting will be the same as if you had a 37t chainring. As a result, together with an 11-speed cassette from Classified, the gear range is 451 percent. The steps between the various gears are less than ten percent.

Exploded view of the Powershift gear hub from Classified

To put this into perspective, here are the gear ranges of common shifting systems:

  • Shimano Nexus 5-speed hub gear – 206 percent
  • Shimano Nexus 8-speed hub gear – 306 percent
  • Shimano Deore 10-speed derailleur – 382 percent
  • Enviolo Automatiq gearbox – 380 percent
  • Shimano Nexus 11-speed hub gears – 409 percent
  • Shimano XT 11-speed derailleur – 464 percent
  • Shimano XT 12-speed derailleur – 510 percent
  • Rohloff 14-speed hub gears – 526 percent
  • Pinion C.12 12-speed gearbox – 601 percent
  • Pinion P.18 18-speed gearbox – 636 percent

3. Inconspicuous and pretty nimble

Shifting is wireless on the Powershfit hub. As a first example, Classified has already successfully implemented this on selected bikes with a Di2 gear lever from Shimano. The signal is transmitted via Bluetooth to a receiver on the thru axle of the rear wheel. From there, an electromagnetic signal is triggered by induction, which initiates the mechanical shifting process. The entire shifting process works much faster than to change from one chainring to another using a classic front derailleur. According to Classified, only 150 milliseconds pass between the actuation of the shift lever and the reaction of the mechanical system.

Initial riding tests by various cycling magazines have shown that this works hassle-free under full load. The manufacturer even mentions 1,000 watts that can impact the system during shifting. This means that there is theoretically enough leeway to consider using it on an e-bike.

Cassettes built from one piece for gear hub Powershift from Classified

Cassettes built from one piece for gear hub Powershift from Classified

4. Minimal extra weight

When choosing between derailleur gears and hub gears or gearboxes, weight plays an important role among other things. How about this in regard to Powershift hub? Well, relatively relaxed. Not surprisingly, the hub with the planetary gear weighs more than a conventional hub. But it gets rid of the second chainring and the front derailleur. The bottom line is 250 grams of additional weight. According to the manufacturer, this is about the same as the system weight of a conventional high-quality 2×11 derailleur system.

5. Everything runs smoothly

Besides the question of weight, there is often the question of friction with hub gears and gearboxes. After all, no one wants to spend energy, meaning muscle power, that is not converted into propulsion. With the Powershift hub, the fact that the planetary gear is only used for a single gear has a positive effect. The unused gears are then locked together and rotate as one. This is not possible with multi-gear hubs. Given this background, Classified promises an efficiency of 99 percent. This seems quite realistic, since there are no bearings or seals in the gearbox that could cause additional friction.

6. Test ride will be difficult

Unfortunately, you can hardly test for yourself how this feels when riding. At the moment, there are only two manufacturers that offer bikes with this drive. One is Ridley with its Kanzo gravel bike and the other is Jaegher. Both also come from Belgium. Classified will supply two more bicycle manufacturers with the Powershift hub in the course of the year, so that they can then build complete bikes. Which ones these will be is currently unknown. For private customers, the drive will probably be available as a stand-alone set in 2022 at the earliest.

7. Closed event

Such a set will then include, among other things, a hub specially made by Classified. So far, the manufacturer has shown cassettes with 11-27, 11-30, 11-32 and 11-34 teeth. All are milled from a solid block. Conversely, this means that the cassettes of other manufacturers are not compatible with Powershift hub. The reason for this is simply the limited installation space. Where there is usually space for the freewheel, Classified has its planetary gear.

8. Future rosy or bumpy?

Details like this make it clear that the road to establishing itself on the market will not be an easy one for Classified. The company has to find the right answers to the following questions:

What installation widths can be implemented for the system in the future?

The width of the rear wheel hub is absolutely crucial. After all, there are standards that manufacturers and frame builders have been using for a long time. On the E-MTB, for example, it is 148 millimetres. On road bikes and gravel bikes with disc brakes and thru axles, the hub usually measures 142 millimetres. This is also the current installation width of the Powershift hub. An adaptation to the mountain bike standard is therefore still pending.

What is the feasible diameter of the rear wheel axle?

This point is directly linked to the previous one. The axle diameter of most thru axles for the rear wheel is twelve millimetres – both for road bikes and mountain bikes. This clearly sets the direction for Classified.

How many spokes are used in the wheels?

Due to the motor assistance and the greater overall weight, the wheel of an e-bike is subject to greater forces than a conventional bicycle. If Classified wants to enter this segment, they have to take this fact into account and equip the corresponding wheels with the necessary number of spokes. At the moment, the count is exactly 24. That doesn’t necessarily sound like e-bike compatibility.

Will the hub be compatible with other cassettes?

Only a Classified cassette currently fits on the Classified hub. It remains to be seen whether enough bicycle manufacturers will accept this and buy the system as a whole. Presumably, however, there is a lot of interest in using well-known components from Shimano, Sram, Campagnolo and Co.

 

Pictures: Classified Cycling BV; Jaegher bvba

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