Nice and wavy
Axle nut not torqued correctly? Adjusters shouldn't have any load from the chain on them.
This post serves as a heads up/education to at least, me. I run Gilles adjusters that apparantly yours are a copy of? I'd give 10 bucks to see a comparison between the Peoples Republic of China piece and the Gilles....and I have no clue as to the difference (but if I was betting, the Gilles sure looks and feels quality, I think they are German?).
BTW, I'm so glad you didn't have a bigger failure at speed! Doyle
I think I am being misunderstood...I mean the torque (twisting force) the bike puts on that sprocket while the chain is pulling it was way too much for cheap aluminum parts in the swing arm to handle. Not the torque of the axle nut..
Improper axle spacing causes that regardless of nut torque. The nut either bottoms out on the threads before axle is actually tight or the axle end binds up on the adjuster an torques without actually tightening the axle. On the majority of aftermarket arms I have installed including bolt on extensions I have had to add a washer to the axle on the opposite side if the nut to make them tighten correctly. The adjusters aren't made to hold the wheel in place. They are only there to adjust. I have had and seen race bikes that the adjuster bolts vibrated loose an backed off and still never had the wheel move like in the pics above.