Chainring guard

thingiverse

Use case: I use a regular (not narrow-wide) chainring in the middle position of a triple crankset; a poor man's 1x drivetrain. I currently use a front derailleur as a measure of chain retention, but I still get rubbing when in either extreme. I'd get a narrow-wide chainring, but they are expensive or not available in the tooth count I want (40-46T) & BCD combination (96 mm). This chainring guard replaces the largest & smallest chainrings to keep the chain from derailing off the middle ring. This was *not* designed for preventing chain derailment off the largest ring (essentially a high limit screw replacement). I have STLs for my own use in 96 & 64 mm BCDs (4-bolt) as a well as a test STL in 110 mm BCD (5-bolt). Has countersinks for standard M8 x 0.75 chainring bolts.