Hi yall
Did anybody else see this rig on bikepacking.com?
https://bikepacking.com/bikes/2026-atlas-mountain-race-rigs-part-one/
2×12 with 10-51 cassette?
Has anybody here ever tried that?
Is it stable?
The gear calculator says it's 790% gear range, and I have to say the idea seems sexy af
by throwawayBecase
2 Comments
Eh, seems to work. They are not moving right now but they have done 89km already and only stopped for 5 minutes.
If it wasn’t stable, then at least the stopping time would be higher.
Obviously this isn’t what Shimano says is compatible but I guess you can make it work mechanically.
Having fucked around with a similar setup:
1) The rear shifts like ass unless you stop and twiddle the B-screw every time you shift chainrings. The upper pulley being highly offset from the cage pivot is a very 1x-specific derailleur design; the upper pulley ends up in wildly different spots relative to the cassette when you change the chainring size but don’t resize the chain.
2) The derailleur does not have enough chainwrap to run both the big-big combo and the small-small combo. You have to think think about which gear combos you are ok with being forbidden when sizing the chain for install, and keep those forbidden combos in mind while riding.
If you really want this you can make it work but you have to be thinking about it at all times. You kind of have to consider the chainrings like a high/lo range on an old 4×4 that you have to stop to shift between, not something that you go back and forth between regularly. Ultimately it was not worth it for me.
If you want ultrawide gearing… with 2×11 GRX you can get factory-quality, zero-compromise shifting with a wide double crank, a 10-42 cassette or 11-46 cassette, and RD-RX812 + the long cage plates off the RD-M8000-SGS (THAT derailleur was designed to shift a triple, it doesn’t care about different chainring sizes). 660% range with the 44/28 crankset I run.