The new sprocket was designed specifically with Shimano’s Zee FR rear derailleur in mind since that mech couldn’t work with the larger 42-tooth ring. We’re thinking it’ll find a wider audience than that when it comes in stock March 17. From OneUp:
The new 40T has all of the same tried and trusted features as our 42T. It’s compatible with most SRAM and Shimano 10X rear derailleurs, no need to be limited to just one drivetrain company! It’s machined from 7075-T6, weighs in at 70g and has 8 upshift points and costs $90 including shipping.
Nick at OneUp also mentioned the 40T is compatible with Saint rear derailleurs when the mode converter is in Freeride mode. They’re still testing with Sram short cages, so can’t yet recommend the 40T with anything other than medium and long cage SRAM derailleurs. Their full compatibility chart is here. More pics below…
We’ve been testing the 42T cog with good results. First impressions posted here.