Bumper reinforcement

Travel trailer > Mods > Bumper reinforcement


Like many others, we've heard the warnings that bikes should not be carried on the rear bumper. Thin bumper material, poor welds and the bouncing action means they're certain to fall off. For years I believed it unconditionally, but not so much now. Why?

First, our bumper is not made of paper-thin steel:

Bumper thickness end shot*

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Second, it is supported by welds in front and underneath:

20170618_083256

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Third, I am adding Mount-n-Lock's 4SQUARE Safety Struts to reinforce it.

The parts and hardware

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Installation is fairly straightforward, but there was something in the way... this trim piece.

Rear trim - secured at back

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To remove it, eight screws had to come out. Two external...

Rear trim - removing screw Rear trim - second screw

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Four in the trim rail...

Exposing the screws Removing the trim screws

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And two more underneath the trim rail.

Screws UNDER the trim!

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My struts had to be a little proud of the frame to clear the weld between the frame and the bottom part of the bumper. I created a template that would allow me to keep the strut flat and straight while I marked the holes.

Spacer plate

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I started by marking the first hole with a 3/8" drill bit through the strut and template. Here's the mark.

First hole marked

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With cutting fluid and a small drill bit I started the first hole.

Cutting fluid ready Drilling the first hole*

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With the first hole drilled and tapped by the bolt, I installed the strut temporarily, aligning the template before tightening the bolt.

Installing the first bolt Bolt in - front Bolt in - back Hole threaded* Drill bits for alignment of other holes

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Here are the marks for the second and third holes.

Other holes marked

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This time I started the holes with my recently acquired step drill. Much easier going, stopping frequently to check the temperature and apply more cutting fluid. Note the black band... a reminder to stop after 5/16" (the holes were enlarged to the required 11/32" with twist bits).

Using the step drill - MUCH better

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All three holes drilled.

All holes drilled and threaded

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Installing the strut with two spacing washers on each bolt.

Bolts and washers going in Bolts and washers - closer All bolts tightened

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Nuts installed on the back for extra security.

Nuts installed and tightened

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With the lower trim piece on, I applied some butyl tape to the back of the trim rail. After installing the screws I popped the cover back in place and caulked the end. Yep, I need caulking practice!

Butyl tape under trim Trim rail cover reinstalled, end caulked*

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The second strut went on much as the first one did.

Strut installed - 01 Strut installed - 02

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The spare tire will have to slide to one side to accommodate the bike rack; I removed it for now to give the bumper a good cleaning.

Bumper cleaned and ready for bike rack

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Rut roh... looks like it's bikes OR spare, not bikes AND spare.

Looks like it's bikes OR spare, not bikes AND spare

I took the spare off; we'll carry it in the truck bed for now. If we like the rack back there, we'll find another way to carry the spare.

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Here's the rack on the bumper.

Rack installed - 01 Rack installed - 02 Rack installed - 03

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Now for a stress test. Note that I weigh twice what the three bikes do, and I am applying my weight to the end of the rack instead of the whole thing. The suspension compresses and rebounds and the bike rack flexes. but the bumper does not.

We'll give this a try on our upcoming trip and will report back afterwards.

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