Building up a 61T myself right now, with a GRX 810 mechanical groupset:
- fc-rx810 crank (48-31)
- rd-rx810 rear derailleur
- fd-rx810 front derailleur
To get some extra gears I was going to install a SRAM 11-36 cassette (Model 1170) and a SRAM chain. Now I'm struggeling to set up the front derailleur. When on largest cog and small chainring the chain touches the derailleur, even with no tension on the cable.
The 36 cog barely fits, there is only very little room between the cog and the pulley. So my problems might already start there?