I want to set up a drop bar bike with a SRAM Transmission derailleur (not XPLR, the MTB derailleur). This is definitely "a thing", SRAM posted it on their own Instagram. I'm struggling to find a chainring that is "gravel" sized (40t and up) and maintains the 55mm chainline. The frame I want to use is a drop bar frame with MTB-style boost spacing, not normal road spacing.
SRAM's MTB chainrings come in 0mm and 3mm offset, and my understanding from Wolf Tooth's chart here is that if I buy a SRAM Transmission crankset ("DUB wide MTB"), then I need a 3mm offset.
I can't find any larger chainrings that aren't 6mm offset:
- SRAM's chainrings don't list the offset on their own page, I think it's 6mm though.
- Wolf Tooth's own page does not list offset, but I found another seller that says it is 6mm. They offer multiple offsets for "MTB" sized 1x chainrings but not "gravel" ones.
- Alugear doesn't specify that it is compatible with T-Type and it is 6mm anyways.
- Garbaruk is 6.5mm
Then there's this confusing help page on SRAM's website that says you can't use road chainrings with Eagle Transmission cranksets, and this one that says that it works fine as long as you use the wide crankset and bottom bracket. But that still isn't 55mm chainline, it's 47.5mm.
- Do 3mm offset chainrings with 40t and up exist?
- Will using a 6mm chainring work with a Transmission crankset? It will just be 52mm instead? If SRAM says that it's fine with the 47.5mm even though it's supposed to be 55mm, is 52mm better?
- Is being off by 3mm here not a big deal?
by hdhdhdhdffff
1 Comment
I have a Rival chainring + crank with a T-type drivetrain and it works great.