The belts and teeth usually have a central line which stops them shifting sideways. There is usually too low tension if it's able to come off. Maybe that could come from frame flex, I don't know. Have you got a snubber installed?
There is a snubber. I've just adjusted to be in contact with the belt, hopefully that keeps it from happening again?
@gillies started
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The belts and teeth usually have a central line which stops them shifting sideways. There is usually too low tension if it's able to come off. Maybe that could come from frame flex, I don't know.
Have you got a snubber installed?