When SRAM first announced their Universal Derailleur Hanger (UDH)
, it was touted as a way to ensure that finding a replacement would be an easy and relatively inexpensive task. It turns out there might be more to the story, at least based on a patent that was recently granted
to SRAM's German division with the catchy title of 'Drive arrangement for a bicycle.'
The patent language describes what sounds like a fairly typical drivetrain, but the illustrations make it clear that there are difference between this derailleur design and SRAM's current offerings. The derailleur uses a direct mount design, and the body is tucked much further underneath the chainstay compared to what's currently the norm.
It appears that if a frame was designed to use a UDH, then it would be compatible with this new derailleur. In other words, the UDH acted as a benevolent Trojan horse, bringing inexpensive replacement hangers to consumers while also opening the door other mounting possibilities, which seems like a smart way to introduce a new standard.
It should be noted that the first patent applications for this design were submitted back in 2018, and the patent was granted in April of 2021, so some of the illustrations seen here may be familiar. Shimano also deserves a nod for introducing a direct mount derailleur back in 2012
, although that didn't really change the orientation of the derailleur in relation to the frame, and it also never really caught on.
According to the background portion of the patent, “A rear derailleur configured for greater stiffness may omit an intentionally weak mount. In this configuration, it may be beneficial to locate the rear derailleur at a relatively inboard position so as to protect the rear derailleur and frame in the event of an impact.” As the gear range of cassettes has grown wider, derailleur cages have grown longer, which means they're more exposed to potential impacts. It looks like this design could potentially allow for a shorter cage derailleur, or at the very least help keep it out of harm's way. In addition, an overall stiffer rear derailleur would help with shifting performance, a benefit when you're dealing with a 10-54 tooth 12-speed cassette.
The new derailleur design also seems to do away with the conventional B-tension screw, the one that can sometimes back out and throw a derailleur out of adjustment. According to the patent, the positioning will still be adjustable during installation, but once the derailleur is in place it's designed to stay in that orientation. “The rear gear changer has at least an adjustment state and an installed state. In the adjustment state, the gear changer mounting unit is not fully secured and may be rotationally adjusted about the rear axis. This adjustment state may be used to rotationally align the rear gear changer for proper tension of the chain.”
The patent also includes detailed description about how the chain will interact with the front chainring and cassette, although nothing stands out as being that
different from the methods SRAM currently employs. However, when (or if) this drivetrain moves from concept to reality it wouldn't be surprising to see it include features designed to improve its ability to shift under power.
Will we see this new derailleur in the real world any time soon? That's a good question - so far we haven't seen anything in the wild, and SRAM's response was 'no comment,' but with racing starting to ramp up we'll be keeping a close eye on SRAM's athletes to see if they're running anything out of the ordinary.