Chain suck guard

After upgrading my 2019 Pivot Trail 429 to 12 speed, I occasionally would get my chain wedged  between the bottom bracket and chainring so badly that I'd have remove the crankarms to free it. Thankfully this has only ever happened in the shop and not on the trail since you need an 8mm hex on a long wrench to break it free (I think its torqued to 56Nm) I never used to have this problem with my 11 speed and I believe it is the design of the steel (cheap and strong) Raceface 12-speed Shimano chain compatible chainring. Anyway, came up with this super simple design that prevents the chain from getting where it shouldn't! Haven't ridden with it yet but on the workstand I think it does what its intended to do! Printed in PLA but may switch to ASA if it doesn't hold up in the sun. Sorry for all the pics but sometimes its the best way to visualize the problem, solution and implementation.

To install on your bike, you'll have to remove the drive side crank arm. Place the disk with raised inner edge toward the bottom bracket over the spacers and put your crankarm back on. Make sure to torque to Raceface's spec (I think its 56Nm) before you ride!

NOTE: This is a solution that is probably unique to the 2019 Pivot Trail 429, the specific Raceface crank (according to Raceface a somewhat custom design for Pivot since bottom bracket is 24mm and rear axle is 157mm Super Boost +) the spacers required and the new Shimano 12-speed chain compatible steel Raceface chainring I installed.

UPDATE 3/16/26: This thing works like a champ - I haven't had my chain stuck since I installed it and the PLA seems to be holding up just fine.