You don't really need it for a cable actuated RD - there's nothing holding it from moving inwards, unless you're on the limit screw.
sounds like someone skips wrist and ankle day at the gym.
Most SRAM rotors are (were?) 1.8mm thick.
Ah, that's mine.
Its an AT Overland Habitat. Folds open like so:
I can't speak to any combinations specifically. Some of those may very well work just fine!
Droppers were effectively* non-existent 20 years ago. I'd say ubiquitous droppers have been a pretty huge change in bikes - although they don't require any new standards.
*yes, there were some options decades earlier. Lets not pretend the hite-rite was spectacular for anything other than the concept.
Warning that your seals may not be compatible with other mineral oils.
And you'd still be able to just run a UDH hanger and standard derailleur, should you wish to. Seems win-win, and better set for success than Shimano Direct Mount.
UDH requires the correct axle thread pitch, as the hanger threads to a hollow nut, which the axle threads in to.
There's at least two rear axle head styles (flat and conical Syntace x12), and three reasonably common thread pitches. And an even larger number of widths, even just for 12x148.
Front is just as bad.
Correct - there's multiple axle head standards, and thread pitches.
Transition also has "Universal Derailleur Hanger". Bike brands tend to mean "we have one derailleur hanger that works for all our bikes", which.... is a good step from where things use to be, with 3/4 of the bikes in each brands lineup requiring different hangers, and changing it year over year.
The important difference with the SRAM UDH is that the concept is universal across brands. Brands adopt/design around UDH, shops can stock ONE derailleur hanger SKU for any bike designed around the standard. The giant tackle boxes with "2019 Giant Reign" stickers next to "2004 Norco Shore" are gone.
As a bonus, everything will also be more consistent for derailleur performance. There's a fair bit of variation across brands with how the hangers are built, flex, shaped, etc. Think about any time you've swapped an RD across bikes - you may have had to adjust limit screws and b-tension, because the hangers are in slightly different locations. This is detrimental if you sell derailleurs, and are trying to maximize RD performance. Shimano kinda tried this a decade ago with Direct Mount, but it didn't stick.
It all started in the Black Bear Pub on a napkin.
Agree. HG had seen its time in the sun, and was sorely in need of an update.
All that to say, I just run XD on everything. But if you wanna be annoyed, better check if your gravel hubs are XD, or XDR... this is an article on standards after all.