BLUF
December prototype trip to Berthoud, CO with Sherpa Equipment Co. The first low-profile RTT mount design used a 4-foot threaded rod that proved too short, with a 90-degree bracket cut beating the slanted version. Bolt-head reach got moved closer to the rear bumper for next iteration.
The problem with low-profile racks
Low-profile roof racks look clean, lower drag a bit, and improve handling. They also make accessing your tent mounts a fight — narrow gaps between rack and tent, sometimes requiring crossbar removal to install or detach. The goal of the prototype: a mount you can install and remove without reaching between the tent and the rack.
The test setup
December trip to Berthoud, CO with the team at Sherpa Equipment Co. — they make the 5th-Gen 4Runner roof rack we tested on. 4Runner ready, prototype mounts in hand.
How the prototype works
One side of the mount stays fixed. The other side moves, driven by a threaded rod that slides in and out. That geometry lets you operate the mount from the back of the SUV — no crossbar removal, no reaching into the gap.
The design targets a range of SUVs (4Runner, Bronco, FJ Cruiser) so the same hardware ports across vehicles.
What the first test taught us
Two findings drove the next iteration:
- The 4-foot threaded rod was too short. Need more spacing between front and rear mounts. Longer rod next round.
- 90-degree cut beat slanted. We tried both bracket angles. The 90-degree version mated to the rack crossbars better. The slanted version had marginal contact.
Plus a usability problem: bolt-head reach was awkward. Fix in flight — moving it closer to the rear of the vehicle for next prototype.
What's next
More prototype iterations. The same iterative path produced the Slipstream — the buyable production quick-release mount today.