[caberto]

We carry our two mountain bikes on the rear slide-out bumper all the time. That post with the pin works fine.

I put some foam pipe insulation on the post and secured with duct tape so as not to scratch the bikes. I use a strap to secure the bikes to the post (the eyelet faces outward), and three bungees to put pressure from different points on the platform to keep the bikes from shifting around.

No issues.