As it's newly fitted then I'd guess it just wasn't cranked together tight enough when you assembled..? check + re-tighten lockring after first few rides is advice I've seen bandied about on here by the gurus..
Had you been running it for ages and it slipped out of the blue then it would be much more unusual! and worrying..
As it's newly fitted then I'd guess it just wasn't cranked together tight enough when you assembled..? check + re-tighten lockring after first few rides is advice I've seen bandied about on here by the gurus..
Had you been running it for ages and it slipped out of the blue then it would be much more unusual! and worrying..