Been offered a gravel frame with UDH but I know nothing about that standard. Plan was to build it up with some old components before upgrading the groupset over time. Can I run a 11sp Rival 1x rear mech with that hanger (or will I die)? All of the full builds look to be 12sp groupsets...
Thanks
Yes.
UDH is backwards compatible.
That's the funny thing with UDH. When it's on the bike, it's just a mech hanger like any other. You can argue the pros and cons of how sacrificial it actual is in a crash, but it's just a mech hanger.
It's only when you remove it that things get funky. I say funky, what I actually mean is some new stuff can bolt directly to the frame instead of the hanger.
Whatever you do, dont undo the UDH with the rear wheel or axle in situ. Thats a whole world of pain.