The photo appears to show the Yakima supplied carriage bolts. I've used these mounts on several pickup shells, never a problem. I would agree that you don't want just screws. I would also make sure that the bolt ends and nuts don't fray the side fabric. Lots of quality sealant, too!Jon&Sue_DeArman said:I would not advise carrying heavy loads like Kayaks & Canoes with this setup. Only light screws are holding everything in place and wind can generate massive forces. These attachment plates were made to be mounted with 3/8 bolts & nuts.
Thanks for the info, was it challenging to get to the aluminum frame in order to mount backing plate and bolts?bike4mee said:This is a little larger pic. I have had 4 kayaks on top with no problem. Sheer forces going down on bolts that are attached this way are bomber, Use the largest lag bolts that you can. Thanks for the idea of the foam blocks