Originally Posted by
fietsbob
All the adjustable mounting brackets flex, a bit.
but to make it fit as many bikes as possible they chose to do that.
Consider getting a extra bracket or 2. previous posts have shown the flexing metal fatigue cracks the brackets, but having spares are the field repair.
^ This is very important.
It is far better to have the mounts/brackets flexing and be the "weak" spot in the rack attachment.
Consider if the racks mounting brackets were absolutely rigid. The next weakest spot of support would be either the rack bracket-to-fork attachment screw or the braze-on attachment to the fork.
To have a braze-on and/or fork failure is far more difficult/expensive to repair than a simple bracket failure.