for Cyclocross, manufacturers has offered 1 by stuff for decades .. Campagnolo has had toothless guard rings

for their 144 bolt circle cranks , in 4 diameters for 4 ranges of chain ring sizes.. I used their biggest one

to set up a very pretty 52 36 double fr om a triple , back in the 80's.. have a 110 38 to do My Rohloff bike..
got it from cyclocrossworld.com All City Chainring Guard |