@Frederiksoelver I would also suggest aligning up the horizontal line with the BB as the spec shows. There is a +/- 2 degree allowance though, so you’re probably fine if you’re close.
Some insight though, I design bikes for work and we had to send to SRAM our chainstay lengths at; full extension, sag, and full compression on all of our suspension bikes, and the angle of the UDH at each of those positions. I’m not sure if that is helpful in your case, but it is nice to know that a whole lot of work has been done on both sides of this whole “transmission” debacle to make sure things play nicely together.
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I imagine this was to get your frames listed in SRAM’s database to position the setup key at A or B. This seems odd because the default setting is A; in other words, does it matter?
It would be nice to have some info from SRAM for when to set the key at B, particularly when they say:
When riders default to the A position, what are we missing in terms of shift performance, and what are the real chances of damage? Maybe I didn’t dig deep enough, but I haven’t seen an explanation. Most builders on this forum won’t be choosing from the list of frames in the database, some clarification could help.
You mean they pay you? Everyone I know does it for free!
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After my failed round T-type dropout, I went back to the drawing board and came up with this. It is compatible with UDH and T-type derailleurs. Weighs 53g. Can fit 3/4" chain stays and 5/8" seat stays.
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This looks good. We’ve been beating our heads on the wall trying to come up with a round version, no easy or good solutions. We’ll get into it more when the slider inserts are done.
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Hey Spencermon,
Thanks for your input on the UDH mount angle. Good news, I don’t have to worry about rear-suspension bikes. I’ve been struggling with SRAM’s confusing UDH PDF, and I wish they had mentioned if the angle towards the bb in sag mode applies to bikes without rear-suspension.
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Just out of curiosity, has anyone tried these yet (or is there a 3D CAD floating around somewhere)? They’re made by allotec and the ones you can buy at metalguru…
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I used these on my most recent build and have no real complaints. Carl posted a super blurry screenshot of a drawing, and I was able use that to make a super rough CAD model. It worked for my purposes but I’m weary to share it because I’m certain it’s not accurate
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I reached out to Allotec and they were kind enough to provide the 2D CAD drawings. I will create a solid model when I am bored.
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Oh wow that’s awesome, thank you! I will do that 3D model today!
Cheers Lutz
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C82_assembly_142.STEP (2.5 MB)
C82_assembly_148.STEP (2.5 MB)
Et voilà… It’s pretty accurate but not 100% since I had to pull some dimensions from the pretty pixelated image. But should be good enough for frame building purposes 
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So… we made a thing…
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OOOF! I was thinking about designing this. Looks like I don’t have to now. Haha.
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Wheels MFG FTW!
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When is the next update coming out?
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I’m terrible at predicting these things, but I’m hoping in the next month.
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This just saved me several hours! I’d love to buy you a coffee/beer for your efforts, send me a DM if that sounds good 
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New UDH alert, from Lichen: Ti UDH V2 Hooded Dropout - Lichen Mfg
Solves the fin issue with a 25.4in “forward hood”. A unique take on the solution.
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