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New bicycle gearboxes are coming onto the market quicker than at any time in history.
Until recently, Rohloff was the only gear hub option that you needed to know about. Some Rohloff customers have ridden more than 430,000km on their hubs, which is a testament to the excellent engineering behind the product.
Pinion later came along and offered even wider gear ranges and smaller gear steps with their reliable crank gearboxes. And in recent years, we’re seeing more premium brands such as Kindernay offering lightweight, robust and efficient gear hubs, and Effigear, which have not one but two gearboxes in their product range.
The next wave of gearboxes is currently being developed around e-Bike use, and what you’ll see today is only the tip of the iceberg.
Mid-drive e-Bike motors put a lot of strain on derailleur drivetrains, resulting in faster component wear. As a result, you can expect to see many more low-maintenance, hassle-free, and robust gearboxes coming soon.
Let’s take a closer look at the latest offerings.
3×3 Nine Gear Hub
3×3 is a new brand by engineering company HB-Hightech, and their first bike product is a nine-speed internal gear hub.
Alright, here are the numbers on this German-built gearbox. It offers a 554% gear range, which is wider than both the Rohloff (526%) and Kindernay hubs (543%). This means that when we peg the lowest gears of all of these hubs, you’ll have the ability to ride at a slightly higher speed with the 3×3 hub.
However, there are fewer gears across this gear range, resulting in gear steps of a rather large 23.76%. This is almost twice as much as Rohloff (13.6%) or Kindernay (13.9%), so it’s clear that 3×3 is targetting the electric bike market with their hub. As e-Bikes accelerate faster, it’s not uncommon to find yourself changing 2 or 3 gears at once. The larger gear steps solve this problem but make the hub less suitable for regular bikes.
The 3×3 hub is around 2kg/4.4lb, which is a touch heavier than both Rohloff and Kindernay. But the hub is also rated for 250Nm input torque, which is significantly higher than both of those (130 and 160Nm, respectively). That means you can run a very powerful mid-drive motor if you like.
Interestingly, the hub is lubricated with grease instead of oil.
Why did 3×3 choose grease? They are hoping their hub doesn’t need any maintenance for 25,000km. That’s five times further than Rohloff recommended for their routine oil changes. I should note that greasing the 3×3 hub will be more labour intensive than the simple oil changes of the Rohloff, but it’s nice that it doesn’t need to be tinkered with as often.
Those who have read my Alfine hub resource know that if internal gear hubs are not grease-packed appropriately for wet environments – water can and will work its way into the hub shell. This is one of the downsides of grease lubrication, so let’s hope the 3×3 hubs are well-sealed from the factory.
Additionally, grease is a bit less fluid than oil in the sub-zero temperature parts of the world, which can result in gears sticking and a reduced drive efficiency too. Hopefully, 3×3 choose suitable grease for the coldest regions.
There is an electronic shifter available that’s wirelessly controlled. This can connect to an internal battery in the frame or directly to an e-Bike’s power supply. Alternatively, a twist shifter can be used, which looks to fit on both drop bars and flat bars.
The hub will fit both quick release frames or those with 142/148mm thru-axles. You’ll find the 3×3 hubs fitted to a range of bikes next year and will later be able to order one separately.
Another cool German-made gear hub that’s coming soon is the Reevoluteh Hub1. This is a six-speed hub with a gear range of 400%, resulting in gear steps of over 30%, making it best suited to e-Bikes.
This hub has a few unique features.
Revolute says that the Hub1 is the only gear hub that allows you to shift properly under a load. It’s also the only hub that uses helical gears, although the Shimano Alfine 11-speed uses a mix of helical and spur gears.
The advantage of helical gears is that they are especially quiet. This is because angled gears distribute pressure gradually along the whole tooth, and this gradual engagement allows them to engage much more smoothly and silently. In comparison, spur gear teeth contact straight away and hold together for a longer period of time.
So, why don’t all gear hubs use smooth and silent helical gears?
It’s mostly because they are a bit less efficient. As the gears mesh, they also push apart from each other (axial thrust), which generates an increase in friction (heat). The difference in efficiency isn’t huge, but internal gear hubs are already less efficient than derailleurs, so every little bit counts…
…. until now. With batteries and motors, we can easily mask the slight efficiency loss here. That’s why noticeably less efficient CVT hubs like the Enviolo are popular on e-Bikes, but a bit of a drag on regular bikes.
Another interesting feature of the Revolute hub is that it doesn’t spin backwards! This means that when you stop on a hill, you do not need to pull your brakes to prevent the bike from rolling backwards. This will be especially handy with heavily-laden cargo bikes but would be nice on a regular bike too.
In terms of bike manoeuvrability, you’d think a one-direction hub is impractical. Well, Revolute has gone and added a neutral gear. You can access neutral by pushing the safety button on the shifter and downshifting beyond the first gear.
As the rear hub doesn’t spin backwards, it’s a requirement to have a freewheel at the crankset to move your pedals backwards – that’s whether you use an e-Bike or not.
Like the 3×3 hub, the Revolute will handle a monstrous 250Nm of torque, making it ideal for almost any mid-drive e-Bike. The hub is around 2kg as a result, which is on the heavy side for a 6-speed. Consider that the Kindernay 7-speed is 40% lighter in comparison.
Unlike the 3×3 hub, the Revolute runs on a more common oil lubrication system. The oil change intervals are 5000km like most similar hub designs.
The Revolute uses standard six-bolt rotors and even the 9-spline cogs from a HG cassette body. The straight pull spoke design looks cool but makes spoke replacement a bit easier too. It’s available for quick release or thru-axles, and the price will be around 1200 Euros.
Pinion Smart Shift Gearboxes
Pinion has been producing 6, 9, 12 and 18 speed gearboxes for over a decade now, but has only just got around to introducing electronic shifting. This new electronic trigger shifter is unfortunately not backwards-compatible for current Pinion gearbox owners and is only available for e-Bikes.
The Smart Shift gearboxes are actually an all-new product for Pinion. They are internally different to the existing P and C-line gearboxes as they require a different shifting mechanism and various sensors. But they are based on the lighter and narrower C-line gearboxes. There will be 6, 9 and 12-speed versions.
The new shifter offers lightning-fast shifting speeds and a lighter shifting action too. It has a grippy rubberised button surface for your thumb and haptic buttons so you know precisely when you’ve made your shift. Additionally, you can customise the buttons to shift how you like. The inbuilt gearbox sensors then allow you to know your gear indication on the LED display.
There is an automatic start gear feature that allows you to choose a desired gear that is automatically engaged when the bike is stationary. This means that you’ll always have the perfect take-off gear.
With this level of tech, I think we can assume that automatic gear shifting is likely in the works.
Intradrive Gearbox Powertrain
Intradrive is a Scottish company that has been working for six years full-time on an integrated gearbox and motor unit.
Their prototype gearbox offers eight gears across a 430% gear range, resulting in gear steps of around 23%. This is essentially the same gear range and gear steps as a SRAM Ex1 derailleur drivetrain, however, the main difference is that the large spur gears are protected from the elements inside a sealed oil bath enclosure.
One of the coolest things about this British-built drive unit is that it can be attached to any bike built for Shimano EP8 motors. Even the 630Wh Intradrive battery will be developed to fit the Shimano battery mounting points. This means that bike manufacturers can fit the full powertrain to existing bike models, and current Shimano EP8 users can easily make the switch too.
One of the biggest advantages of this system is that it will wear through fewer drivetrain components. It will also reduce the unsprung mass at the rear wheel of full suspension bikes, improving the weight distribution and suspension performance compared to derailleurs, but even more so when compared to the internal gear hubs I’ve previously discussed.
The motor will offer upwards of 75Nm of torque, which is lower than similar integrated motor/gearbox systems but keep in mind that this gearbox is pitched towards mountain bikes, rather than cargo bikes.
The shifting will be electronic, with the potential to run the gearbox and motor using automatic shifting.
With Intradrive showing that an integrated gearbox and motor can fit onto standard frame mounts – I’d like to predict that we will see something similar from Pinion in the coming years. After all, Valeo and Effigear have been testing their motor for a few years now.
Classified Powershift Gear Hubs
I’ve been looking for an excuse to talk about Classified hubs for a little while, and I think now is my time.
These planetary hubs are a two-speed design and offer the same functionality as a front derailleur. If you fit a 48-tooth chainring up front, you get an effective 33-tooth chainring when using the reduction gear in the hub.
Classified hubs were originally released with complete gravel bikes a year ago, then as complete carbon wheelsets from the company itself. Now, Classified has partnered with Enve, DT Swiss, Mavic and more wheel brands to make their hub more accessible.
The hub uses a thru-axle design and it’s the axle that receives the wireless signal to shift. Classified says that the efficiency in the reduction gear is very high (99%), you can make shifts at 1000-watts power output, and the shifts are almost instantaneous – faster than any front derailleur.
The reason these hubs are great is that you get the simplicity and range of a 1X drivetrain but without the large gear steps of a wide-range cassette. This means you can stay closer to your preferred pedal cadence at a broad range of speeds.
Classified drivetrains also ditch the incredibly inefficient 9 and 10 tooth cogs that are typically found on 1X cassettes, and are designed around larger and more efficient front chainrings too.
I’m actually excited most about the soon-to-be-released MTB version, allowing off-road riders who ride on flatter terrain to fit smaller cassettes (ie. 11-40t) instead of the ubiquitous 10-52t models currently on offer.
I hope these new gearboxes got you a little bit more excited about this quickly evolving drivetrain tech.
Let me know in the comments if you come across any prototype gearbox drivetrains in development, as it would be great to analyse their designs in future articles.