I noticed this happens a lot on this forum, more than any other forum I know of. Old topics being bumped is an annoyance for a forum's users and a hassle for it's moderation. I suggest adding a plugin like this one: https://xenforo.com/community/resources/tpu-show-warning-when-bumping-old-threads.3913/ oddly enough that addon has the same exact as this thread... This would prevent or defer users from posting in old threads unless they truly believe they have any valuable input and not just "omg lol". It would also prevent the accidental thread bumping which happens from time to time. That being said, it would also allow for any additional discussion that wouldn't be possible if the thread was automatically locked like some forums do. An appropriate time frame would probably be something around 3-6 months, as the community is very fast paced and a lot of the topics are help or other "garbage" threads that don't need long term discussion.