Mike Jacoubowsky said:Apparently that's the case if you want to use Ortlieb panniers; I'll take
your word for it. But it's certainly capable enough for others. We sell a
fair number of 520s, and they get used pretty heavily. It's a bike that
almost never comes back with problems. Very conservative design, downright
boringly so. For excitement they change the color to a different shade of
green from time to time (although the current one is actually black I
think... how rad!).
I counted six obvious issues with the 520 rack.
First of all, touring racks should have three struts for sufficient
stiffness and strength for fully loaded touring.
Second, the rear strut should be a “dogleg” strut because this keeps
panniers from hitting the wheel when they are mounted toward the rear.
Blackburn realized this with their Expedition EX-2 rack, which updated
their popular EX-1 which lacked the dogleg.
Third, the struts should meet very close to the threaded mounting hole
by the rear axle.
Fourth, double tubing should not be used at any point along the side
rails, as many pannier mounting systems won’t work with double tubing
(i.e. the Arkel mount). At a minimum, the double tubing should not be
near the back of the rack.
Fifth, there should not be a load stop at the front of the rack (though
Trek is hardly alone in this).
Sixth, if positioning panniers toward the rear, there is no place to
attach the bottom hook of the pannier's shock cord without bringing it
down at at about a 40 degree angle, which tends to lift the front hook
up off the rack.
On the plus side, It does appear to be a rather long rack. It's also
probably very light.
I think Trek realizes that the 520 is not really a touring bicycle, and
that no one is going to pile a tent, sleeping bag, and heavy panniers
onto that rack.
Since Trek listens to you, maybe you can encourage them to switch to a
better rack on the 520.