BLUF
Episode 6 is the rattle-and-noise testing pass on the SUV low-profile mount. Five rounds, four distinct noise sources, and the fix that finally killed the clunking: a quarter-inch spacer raising the tent half an inch off the rack.
Round 1: where the movement was actually coming from
The mounts moved barely at all. The tent moved a lot. The two crossbars supporting the 200-lb tent flexed under load. First mitigation: high-density rubber pads on the crossbars to spread the weight more evenly.
Round 2: spreading the load
After lowering the tent onto the rubber pads, results improved. But big hits still flexed all three crossbars and let the tent tap the rack. Next move: more rubber pads, more contact points, weight spread across four crossbars.
Round 3: four distinct noises
With the padding in, four separate noises showed up:
- Tent contacting the rack — minimal clearance between tent and side plates.
- Creaking — metal-on-metal between crossbars and side plates.
- Soft thuds — tent belly tapping the rubber pads.
- Plastic tapping — ABS slider assembly hitting the extrusion.
Fix for the creaking: nylon washers between mounts and crossbars to isolate movement and reduce friction.
Round 4: the breakthrough
Nylon washers killed most of the creaking. With that gone, smaller noises surfaced — the ABS slider tap was real but quiet. Bigger problem still on the table: not enough clearance between tent and rack.
Round 5: the spacer that fixed it
After consulting with Sherpa Equipment Co., we put the rear crossbar back in for stability. Tent was still too close to the rack. Quarter-inch spacers raised the tent half an inch. That eliminated the clunking. Accelerometer instrumentation on the rig confirmed the numbers.
What the production mount inherited
Repositioning the crossbars closer to the mounting points won out. Less rack movement. Quieter ride. The same testing approach fed into the Slipstream production mount — the buyable SKU today.