I was a long time user of an old Thule boot rack - never had any problems with it till I started to update my old-fangled skinny steel tubed bikes to modern chunky tubed bikes (which it doesnt fit). So I bought a new boot rack from Hulfuds (sic) and on my first run up from the big smoke to Thetford, got out at the end to find my rack and bikes had slackened off and were hanging on by a wish and a prayer. I will never use it again. Currently looking at a Thule 591 roof system, but worried the chunky square tubes on my '07 Marin Attack Trail will escape sideways from the frame clamp.... Advice welcome...