Home > Other Fun Stuff > Prototypes & Concepts

Shimano Files Patent for Direct-Mount Rear Derailleur with Rigid “Bracket Device”

shimano direct mount derailleur patent mechanical bracket device extra rigidity
18 Comments
Support us! Bikerumor may earn a small commission from affiliate links in this article. Learn More

While SRAM has stormed ahead with the release of their Eagle Transmission, it turns out Shimano too has been quietly working on a Direct-Mount Rear Derailleur of their own, as revealed by a patent published last June. First reported by BikeRadar, US Patent 20220204134 A1 describes and depicts a rear derailleur mounted to the dropout in a very similar fashion to the T-Type Direct-Mount Derailleur from SRAM; i.e., a hanger-less design with a mounting portion that occupies space on both faces of the drive-side dropout.

The patent document in question centers around the “bracket device” of the rear derailleur, and shows it in use with what otherwise looks like a regular mechanical rear derailleur. Let’s take a closer look.

Shimano Direct-Mount Electronic Derailleur

The most interesting sentences of this Shimano patent, which are referring to that “bracket device”, are the following: “The frame attachment end has a first arm and a second arm, which are spaced apart in an axial direction with respect to the rear-wheel axis. The first arm has a first attachment opening through which the rear-wheel axis coaxially passes in amounting state of the bracket device. The second arm has a second attachment opening through which the rear-wheel axis coaxially passes in the mounting state of the bracket device”.

shimano direct mount derailleur mounting bracket rigidity two pronged

That’s a rather dry way of describing what can be seen in Fig. 2 and Fig. 7. These shed a bit more light as to why we’ve bothered sharing the contents of this patent document with you readers. Looks familiar, doesn’t it?

Indeed, the two-pronged attachment wraps the “bracket device” around each side of the dropout, and is secured in place by a threaded bolt running through the center. The design is not terribly dissimilar to SRAM’s Direct-Mount Derailleur that was released last week as part of their T-Type Eagle Transmission.

shimano direct mount derailleur patent shown mid-travel emtb cable actuated mechanical

In Fig. 1, the rear derailleur is shown on what looks to be a mid-travel eMTB, suggesting the derailleur will find its home on a mountain bike, likely paired with a 12s cassette. In all instances, the derailleur is depicted as cable-actuated, unlike SRAM’s Direct-Mount offering which offers electronic shifting. Interestingly, the Shimano patent shows their mechanical direct-mount derailleur with use of a pulley wheel for guiding the cable to its clamp – a design more commonly associated with SRAM’s derailleurs.

shimano direct mount derailleur bracket portion with bscrew angular position adjustment

Importantly, it looks as though this Direct-Mount Derailleur from Shimano will be able to accomodate different size cassettes. Labelled as 54 in Fig. 4, a screw is positioned around about where you might expect to see the B-Screw. The document describes this portion as the “angular position adjustment structure”. It serves to dictate the position of the rear derailleur relative to the frame and thus the sprockets of the cassette. Shimano’s Direct-Mount Derailleur also shows the usual High and Low Limit Screws in Fig. 9. These aspects are in contrast to the SRAM T-Type Derailleur which is designed specifically for use with a 10-52T cassette, and thus has no use for B-Screw.

shimano mechanical direct mount derailleur with rigid bracket device

Shimano’s patent touches briefly on how this design with its “bracket device” offers an improvement over existing designs, stating “The bracket device according to the first aspect reduces the amount of the rear derailleur projecting from an axial center plane of the bicycle and increases the rigidity of the rear derailleur. Further, the distance between a rear sprocket and the rear derailleur is easily adjusted and thus the usability is improved”.

sram transmission direct mount rear derailleur installation closeup
A close-up of the SRAM Direct Mount Transmission Derailleur during installation

What isn’t clear from this filing is whether or not this rear derailleur design would be compatible with the SRAM UDH style dropout that has been almost ubiquitously taken up by frame manufacturers across the industry, and of course, whether or not it impinges upon the patents related to SRAM’s Transmission. Either way, it seems highly likely Shimano will eventually mount a response to last week’s big move from SRAM – there’s just no telling when.

No electronic version? It certainly looks as though there could be one in the works. As PinkBike reported, another Shimano patent that was published just last week describes a wireless electronic derailleur that appears to be Direct-Mount, too – though, the mounting style is really quite different to what we have so far discussed – it is actually more reminiscent of the brand’s original direct-mount offering seen on a 2013 SLX Group. Also, this electronic option is paired with a 9s cassette in the drawings, indicating it is most likely intended as part of a drivetrain for DH Bikes.

Figure from US 11608139 B2 relating to a wireless electronic direct-mount derailleur from Shimano

shimano.com

Subscribe
Notify of
guest

This site uses Akismet to reduce spam. Learn how your comment data is processed.

18 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
hmmm
hmmm
10 months ago

broken frames in one, two, …

SomeGuy
SomeGuy
10 months ago
Reply to  hmmm

That’s not what happens here. This hanger is secured over a through axle, which passes through the hub axle. You’d have to bend or break your axle before that derailleur could break your frame.

Forrest
Forrest
10 months ago
Reply to  hmmm

not quite. This design, same as SRAM places all of the load on the rear through axle, which is incredibly stout.
Better shifting, stronger drivetrains in one, two, …

Exodux
10 months ago

This looks like Shimano’s answer to the new Sram direct mount. From what I see in the drawings, it appears that the frame would remain the same for both systems. There was a report of this on BikeRadar earlier this morning with many posters sharing their concerns of a different frame for either Sram or Shimano, but my guess this is not the case.

Chris I
Chris I
10 months ago
Reply to  Exodux

I disagree. I commented on BikeRadar too. If Shimano doesn’t use the UDH, then you now have a frame mftr having to choose SRAM UDH or Shimano UDH (or whatever they’re gonna call it). That’s an epic fail for consumers

Dan A
Dan A
10 months ago
Reply to  Chris I

Yeah, it’s a good thing everyone uses the same bottom bracket standard, too.

Chris I
Chris I
10 months ago
Reply to  Dan A

False equivalency.

If SRAM “patented” a 73mm wide shell with metal reverse threads……and then convinced/bribed frame mftr’s to only produce bikes with that BB setup (regardless how high the BB sits), and then SRAM patents the actual BB that can be used in it or licenses the patent out for profit to Shimano/CK/Enduro/Wheels Mftring/Hope/Cane Creek/RaceFace/etc etc since they monopolized the BB, then we’d be on the same page.

When SRAM patented and then licensed this dropout shape, they explicitly are not interested in creating an open standard.

Andrew
Andrew
10 months ago

Suddenly all of the Sram haters are going to become OK with direct-mount hangers in 3…2….1….

kevin
kevin
10 months ago
Reply to  Andrew

no thats funny

Greg
Greg
10 months ago

Whiners. 3…2…1

Hamjam
Hamjam
10 months ago

Next, we will have frames that include a removable piece of metal that goes between the frame and the direct mount derailleur. This way you can use either Sram or Shimano on your frame. I don’t what they will be called. Maybe “Derailleur Hangers”?

Exodux
10 months ago
Reply to  Hamjam

I’m pretty certain that Shimano or Sram would not force frame manufacturers to choose a Sram compatible or Shimano compatible frames or the fact that frame manufacturers would not let them do it either.
What I basically see on both designs is a frame that has a through hole that would accommodate both derailleur designs.

Hamjam
Hamjam
10 months ago
Reply to  Exodux

I guess that would make sense, but that would mean that Shimano is adopting Sram’s standard right? Because the hole in the frame conforms the UDH. Is this possible?

Chris I
Chris I
10 months ago
Reply to  Hamjam

which hole are you referring to…..the thru-axle hole or the shape of the UDH dropout carbon mold? It’s not so much the thru-axle hole size that SRAM patented, it’s the carbon mold shape with a specific design for the UDH’s stopper tab.I have no doubt SRAM is bribing/kickbacking with frame mftr’s on all this.

Hamjam
Hamjam
10 months ago
Reply to  Chris I

Exactly, This whole thing seems crazy. Shimano is a Japanese company that wants to make sound decisions for the next 10 years. They will not rush and react to Sram.

Blair
Blair
10 months ago

Saint and Hone are now in the modern era.

whatever
whatever
10 months ago

Companies file patents all the time to prevent someone else using and ideal, or to maintain a foothold in a space whether they ever intend to use it or not. Got to wonder if that is what is happening here. Or maybe this is a just in case SRAM does manage to make theirs work. Doubt there are many outside of some Shimano people know what or if any plans to use this..

Chris I
Chris I
10 months ago

If folks here would actually go the UDH site and look at the technical drawings, they’d quickly see the problem here.
Component co’s in bed with bike mftr’s to alter their carbon dropout shape mold to one that the component co owns/patented/licenses. This is how monopolization starts.

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.

Subscribe Now

Sign up to receive BikeRumor content direct to your inbox.