Bam Margera's clearing the air about why his UK tour got the axe -- and while some have suspected it's all about him falling off the wagon ... he's saying he's clean and sober.
Here's the deal ... Bam's been across the pond lately for a string of Q&A gigs he'd booked through a promoter -- where he was scheduled to talk to audiences ... all of which recently came to a screeching halt after the peeps he was working with nixed his appearances.
There's been a lot of accusations and drama brewing in the background this past week -- with allegations that Bam was acting erratic and rolling with a new crew of misfits.