I thought I would share my Boxster modifications to facilitate installation of a hitch receiver for a bike rack.
With the previous Boxster and now this one I was always bummed on nice sunny days that I had to take the Subaru to the trailhead with my mountain bike and not the Boxster with the top down. So I finally bought some materials, a donor impact beam from eBay and a 110V Harbor Freight welder package off Craigslist and got to work.
My main criteria for the design and finished project was:
The hitch needed to be hidden when not in use.
Easy to access without any tools.
The hitch will not be used for towing.
Capacity is one mountain bike or two road bikes.
The project revolved around using a 1UP USA bike rack system.
Searching the dark corners of Google and various Porsche forums there are existing hitches out there, many of them homemade, but none of them met my criteria. So I started to figure out how to mount a piece of 1 ¼” receiver tube into the rear impact beam where the tow hook goes. I figured if the rear impact beam is plenty beefy enough to drag the car around and for towing as others have proven, it will be strong enough to hold a bike and a bike rack.
I cut a hole in aft wall of the impact beam to accept a 1 ¼” receiver tube where the tow hook block used to be.
The distance between the bumper cover and impact beam is about 3.5” so that is how long I cut my receiver tube. I then welded two pieces of 1” angle to the tube for mounting to the impact beam. I also welded a piece of flat steel to one end of the tube to cap it off and to provide a place for a bolt common to the impact beam. Yes I know my welds look like crap, but they are stout.
I flipped the tow hook block 180 degrees to the right side, but the left side would have worked to.
The receiver tube assembly is attached by 4 Allen head bolts to aft wall of the beam and one bolt to front wall of the beam.
I drilled four holes in the beam so I could get an Allen wrench in to tighten the bolts.
This design works because the 1UP USA bike rack system doesn’t require a hitch pin through the rack and the tube. You tighten a bolt in the end of the rack and an expander in the rack keeps the rack in the tube.
I modified the bumper cover to provide access to the hitch and the relocated tow hook block. I also added some aluminum angle on the bumper cover to support the hinged license plate bracket.
Threaded Mode
