How can you get a little extra shift precision out of the derailleur on your UDH-equipped bike? Maybe try a full-alloy Robert Axle Project UDH replacement hanger vs. the original aluminum and plastic offering from SRAM.
It’s not really thicker, it’s not lighter, and it costs twice as much. But it promises to be a stiffer, more precise connection between your derailleur, frame, and thru-axle for improved shift performance.
Why Robert Axle Project machined an alloy UDH replacement?
Did you know that the standard SRAM Universal Derailleur Hanger was half plastic? A co-molded plastic sleeve, plastic chain ramp, and plastic threads interface with the dropout of your frame. With a flat aluminum hanger sandwiched in between, which your derailleur actually hangs off. Then, and aluminum bolt squeezes it all together and serves as the 12×1.0mm thread that your thru-axle secures to.
We knew. Tyler broke it down in our What’s up with the SRM UDH? Bikerumor Podcast about a year and a half ago.
But frankly, I forgot. The UDH design is genuinely simpler and has effectively been trouble-free for me on every gravel and mountain bike I’ve ridden with one in the last few years. So, even though it was developed to make hanger replacement easier (well, and to sneak in direct mount derailleur transmissions), I haven’t yet needed to replace a UDH.
But the Robert Axle Project also knew. And they set out to eliminate that plastic to improve how accurately your bike shifts. “Modern drivetrains are precise and exacting and deserve to be mounted to a derailleur hanger of equally precise quality. The Robert Axle Project Universal Derailleur Hanger is made to the exact same geometry as the stock SRAM hanger ensuring a perfect fit to your bike and any drivetrain you’d like to mount to it.“
Robert Axle UDH Replacement – Tech, Pricing & Compatibility
The Robert Axle UDH replacement hanger is CNC-machined in one piece from 6061 aluminum. That does essentially mean the alloy part is thicker in some places (not where your derailleur hangs, though). So maybe it’s less susceptible to bending, too. Then, it gets a matching 6061 alloy retaining bolt with a 12×1.0mm thread pitch to secure the hanger to your thru-axle.
It sells for $32 and comes only in anodized black. (If you need some shiny color, maybe try the more expensive option from Wheels Mfg.) But, while there’s just one Robert Axle Project UDH, it will work with all UDH-ready frames, including Trek Active Braking Pivot frame designs. And it will work with all conventional derailleur drivetrains, including ebikes.
Get one direct from Robert Axle or your local bike shop now.
