A bit of strange one , riding yesterday started getting a slight creek, thought it was new shoes rubber,
Creek got louder and louder , looked down and the chainring looked bent.

Stopped, Turned bike upside down, chainring wasn’t bent.
Those mini tamper proof bolts (not even listed as a part on the exploded diagrams) were missing on the direct mount Xt m8100 (crm85) chainring,
Two sets of mini bolts missing, hence chainring lateral movement.

Chainring is 16-18 months old, is this a warranty issue.
Should I (or shimano) have threadlocked these.

The bolt looks to be torx but with an inner hole, will investigate today.
Can these bolts be bought?

I’ve ordered a replacement chainring, but will speak to shimano rep next week

Is this rare or happens often? No hits on Google

TIA

Happened to me. Bloody annoying. The remaining ones were too tight to remove with a security torx bit so it seems to be poor QC on threadlock? Couldn’t find spares or suitable alternative, would be interested to know how you get on as mine was over 2 years old but it fell off my mental to do list and I still have a usable chain ring in need of bolts. Pretty poor imo given that it is designed to be non-serviceable, so why not use a rivet?

A Unite direct mount chainring would sort it, it’d be lighter too but you’ll need to buy a specific tool to fit it.