The rack is not properly designed. The grabber arms
on top are about 5 inches too long, so if you set
the platform level to the ground, the "grabber"
will extend beyond the cross bar of the bike by
that amount. If you are determined to leave the
platform level, you have to tilt the bike out
away from the car. This is extremely dangerous
because the bike could easily fall out of the
grabber and drag behind you. So, your only recourse
is to open the frame wider to about 8.5 setting.
This tilts the platform towards the car, but not
too much. Then the bike leans towards the car,
and the grabbers will actally "grab" the bikes
crossbar and hold it firmly .. and safely .. I
tested it on rough roads. Even so, you would be
nuts not to bungie the bikes crossbar to the
grabber rail. And I also bungie the wheel straps.
Also, I wish the cable ratchets moved better.
So, as designed, if you follow their instructions,
the unit is not safe. If you follow my instructions,
the unit works fine even on rough roads.