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Is Shimano working on a hub-charged electronic shift system?

New patent suggests Shimano is working on an electronic shift system that’s powered by a hub dynamo

Shimano has just been granted a patent for a new rear derailleur hanger that suggests it is working on an electronic shift system that’s powered by a hub dynamo.

Why would we draw this conclusion? Well, US patent 2023/0166813 for a ‘Bracket apparatus and bracket assembly’ is detailed, giving us 55 pages of pictures and explanation. Although the focus is on the bracket – which is how Shimano describes the rear derailleur hanger – the interesting stuff concerns what surrounds it.

> Your complete guide to Shimano road bike groupsets 2023 — Everything you need to know

Okay, so the hanger attaches to the bike frame and the derailleur attaches to the hanger – nothing unusual there – but then things get… strange.

As well as extending downwards from the dropout in the usual way, the derailleur hanger reaches forward, running next to the inner face of the chainstay. Interesting!

Why would it do that? Because at the end of this forward extension there’s a mount point for another component.

2023 Shimano rear derailleur hanger patent - 2

Obvious question: what would that component be? Shimano keeps its options open – patents usually cover as many possibilities as possible to stop anyone else muscling in on the territory – but says that the component would contain an electric device.

“The electric device includes at least one of a battery, a generator, a sensor, a communicator, an actuator, an informing unit, a display (eg a light emitting diode, a liquid crystal display), a user interface (eg an operating switch, an on-off switch), and a compactor for an electric cable. However, the electric device is not limited to the above examples.”

The derailleur hanger features cable grooves. The cables that slot into the grooves connect different components.

> Check out our review of Shimano's Ultegra R8170 Di2 Disc Groupset

Shimano suggests that examples of one of these components could be “an electric power source and a hub assembly including a power generator”. In other words, the derailleur hanger is specifically designed to take power generated by a hub dynamo to other components.

Shimano already offers hub dynamos and we know that it has been working on a new design because another recently published patent application (US 2023/0037945 A1) tells us so.

Shimano goes on to suggest that the hub dynamo could be connected to “an electric derailleur, an electric power source, and other electric components such as a control unit”.

Again, Shimano is covering a range of possibilities but it’s interesting that it sticks an electric derailleur at the top of the list.

Shimano continues, “Electricity is supplied from the electric power source to the motor and/or the controller of the electric derailleur via the first cable.”

Why would you want an electronic rear derailleur that’s powered by a hub dynamo?

Shimano's current Di2 electronic shift systems use derailleurs that are powered by a central battery housed inside the frame (rather than each derailleur having its own battery). Di2 batteries last ages on a single charge, Shimano claiming “approximately 1,000km [625 miles] of worry-free riding” for its 105 system, for example, but generating your own power would mean that you’ll never find yourself out of charge when riding in the back of beyond. That might be handy for multi-day bikepackers, although that’s a relatively small market, or for anyone else who struggles to keep on top of regular charging.

Shimano says the human power vehicle its design is aimed at could be a mountain bike, road bike, city bike, cargo bike, hand bike or recumbent bike. It could also be an electric bike… so pretty much anything, then.

2023 Shimano rear derailleur hanger patent - 1 (1)

One feature that makes us think that Shimano’s new rear derailleur hanger isn’t especially focused on road bikes is that one embodiment described in the patent includes a “chain stabiliser” with two prongs that are designed to point into the gaps between sprockets “to remove foreign material”. That sounds like something that would be more useful off-road.

> Shimano files patent for app that can tell you when bike tyres and disc pads need replacing

A final feature that’s worth a mention is that the pictures show a small button on the inside of the chainstay right next to the rear derailleur hanger. That button isn’t labelled in Shimano’s patent and its purpose isn’t explained so we’re not sure if this is something that frame manufacturers will be required to add.

Overall, this patent is a really odd one and we’re not 100% sure what to make of it at the moment. We’ll keep our eye on new publications over the next few weeks for more clues.

Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now over 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.

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18 comments

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kingleo | 11 months ago
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A long time ago I had two seasons racing Belgium - the Campagnolo super record setup I used worked perfectly all the time - it was just my legs that did not work very well!  I can see someone losing a world championship soon because of a faulty electronic gear changer - they are very unreliable.

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joules1975 | 11 months ago
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That looks to me like Shimano also potentially doing a Sram by creating a mech hanger than can ultimately be switched out for a direct mount mech, similar to the new AXS mech.

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jaymack | 11 months ago
5 likes

Are cable actuated gears really so bad? I move a lever, the gear changes. If the changes become a bit sloppy a tweak of a barrel adjuster has everything sorted for months to come. Batteries are far from the best choice for such a great and green technology. Perhaps a dynamo system would help address that issue. I accept that I'm old and grumpy but 'new' isn't always better. It's a bit like electric powered bikes, great if you've got an injury, have an issue that would otherwise prevent you getting out but as an alternative to the entirely human powered machine it just seems bizarre. And before anyone asks, yes I do still play vinyl records!

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chrisonabike replied to jaymack | 11 months ago
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Recorded music? You're talking sheets of paper you can get played using musicians, right - not some kind of electronic reproduction?

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jaymack replied to chrisonabike | 11 months ago
1 like

You're right of course, you can't beat live music

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chrisonabike replied to jaymack | 11 months ago
2 likes
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jaymack replied to chrisonabike | 11 months ago
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You deserve a 'like' for that...

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lio | 11 months ago
1 like

Di2 has a major design flaw which is why you rarely rarely see it on modern mountain bikes; where do you put the central battery if you have a dropper post?

Droppers are amazingly useful and I whish I had one on my road bike for descending.

SRAM got round that issue by using small batteries mounted on the derailleur. Shimano's problem is that SRAM has a patent on that seemingly obvious idea. 

So Shimano are probably driven to search for new solutions, go to court to challenge SRAM's patent or be locked out of the electronic drivetrain market.

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KDee replied to lio | 11 months ago
0 likes

Does that mean Campagnolo is licensing SRAM's design for on-derailleur batteries?

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Miller replied to KDee | 11 months ago
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KDee wrote:

Does that mean Campagnolo is licensing SRAM's design for on-derailleur batteries?

No, they are not, leaving aside the question of whether Sram would ever have agreed anyway. Campag have worked round the Sram patent by having separate front and rear batteries and a different attachment method. Which is not ideal but works. Shimano avoided sram by retaining wired power supply for the 12v derailleurs.

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KDee replied to Miller | 11 months ago
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Campy are using separate batteries front and rear, but unlike SRAM they're not interchangeable. So with Campy, you can't bung the front mech battery on the rear mech to get you home if the rear battery dies. 
 

Anyway...we digress. What exactly are Shimano up to with this?

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IanMSpencer replied to lio | 11 months ago
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Some time ago Shimano patented a Di2 dropper post - doesn't seem to have seen the light of day, but they do have an external battery mount and I reckon someone cunning could work out how to fit Di2 and a dropper post with an internal battery.

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marmotte27 | 11 months ago
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IanMSpencer | 11 months ago
2 likes

Could be the other way round, feeding power from a battery to the hub for a Classified competitor. How about an Alfine derived 12x7 Di2 setup?

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KDee replied to IanMSpencer | 11 months ago
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Funny, but I was thinking similarly. Electrically shifted hub gear, but I would expect something like a battery powered automatic shifting hub for e-bikes.

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Miller replied to KDee | 11 months ago
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Shimano alfine is available in a di2 version. Quite expensive I think.

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IanMSpencer replied to Miller | 11 months ago
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Not been following closely, but I think Shimano have arrived at the point of being able to deliver an automatic drive train with e-bike, Di2 and electronic Alfine controlled with the help of the torque sensor.

I've been saying for a while that Classified's solution is very expensive and probably not protectable given the prior art of hub gears. 7x12 is overkill (even with electronic management I can't imagine a scenario where that amount of gears would be useful), but an electronic triple hub could make a very attractive gravel solution. MTB market is going very e-bike oriented and you tend not to need the fine tuning of gears with assistance.

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Rendel Harris | 11 months ago
3 likes

Phew, no more having to plug the bike in once every 1500km misery, that's a gamechanger, take my money!

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