The former champion cyclist -- whose accolades were, by and large, rescinded after he was found to have been doping through a decent amount of his career -- teased a new project he appears to have in the works ... one in which he's getting into the polarizing topic.

His key subject, it seems, is going to be Caitlyn ... who's been very outspoken on having trans women competing in women's sports, and who's obviously transgender herself.

Right off the bat, LA's tone to this whole thing has turned people off. He writes, "Have we really come to a time and place where spirited debate is not only frowned upon but feared? Where people’s greatest concern is being fired, shamed, or canceled? As someone all too familiar with this phenomenon, I feel I'm uniquely positioned to have these conversations."

He followed up with more tweets, sorta answering his own Q ... and plugging this new series he's got coming out. One tweet that's got a lot of reaction reads, "Is there, not a world in which one can be supportive of the transgender community and curious about the fairness of Trans athletes in sport yet not be labeled a transphobe or a bigot as we ask questions?

He continues, "Do we yet know the answers? And do we even want to know the answers?"

Now, Lance is trending on the Bird app ... for all the wrong reasons. You can hop into the trend to see what people are saying for yourself -- but it essentially boils down to ... dude, you're the last person who should be commenting on fairness in sports. Like, c'mon.

Of course, they're referring to his PED scandal in the early 2010s ... which he denied for a long time -- but ultimately confessed to. As most of us know, a majority of his titles between '99 and 2005 were stripped ... and his legacy as an inspirational winner was dinged.