Offroading Forest Lake Trail – Core 4x4 Hits the Trails in American Fork Canyon
After months buried in the shop building parts, the Core 4x4 crew finally broke free for their first trail run of the year. The destination: Forest Lake Trail on the Alpine Loop in American Fork Canyon, Utah. The lineup: a fully built JK Wrangler on 40-inch tires, a JL Wrangler with moderate mods, and a Toyota Tacoma along for the ride — or at least as far as it could go.
Getting Trail-Ready: Tops Off, Tires Aired Up
The JK had been sitting all winter with the tires aired down, so step one was getting air back in just to make the freeway drive to the trailhead. The irony is not lost on anyone — airing up to 30 PSI only to air right back down to 10 PSI once they hit dirt.
With the freedom panels off and the weather cooperating, the crew ran through the pre-trail checklist: air in the tires, grease on the JL's arms and end links, tools in the back, and leftover fuel from the JK long arm build video burned off before it went bad. The JK had all-new parts, so no greasing needed — just a quick once-over and out the door.
Air Down and Disconnect – The Most Important Trail Prep
Once at the trailhead, the team aired down using preset automatic deflators — small valve-stem attachments that release air to a dialed-in PSI and stop automatically. On the JK with 40-inch Mud Grapplers, that target was 10 PSI.
Spence makes the point clearly: you can have the best shocks, the best springs, the best control arms in the world, but none of it matters if you do not air down and disconnect your sway bars. Running trail tires at 40 PSI means you feel every rock. Drop to 10 and the tire wraps around obstacles, giving you traction and a smoother ride.
The JK runs no sway bars at all. The JL had the rear sway bar removed and uses a Rubicon disconnect on the front — a popular mod that lets you manually unlock the bar without pulling end links. The Tacoma, unfortunately, had no disconnects and was stuck at 24 PSI on 33-inch tires with 17-inch rims. Not ideal for what was coming.
The Rock Garden – Where the Tacoma Stayed Behind
Forest Lake Trail starts with a rock garden that serves as a natural filter. If your rig can handle this section, the rest of the trail is manageable. If it cannot, this is where you park and wait.
The Tacoma parked.
The JK and JL pushed through without much drama. The JK on 40-inch tires, lockers, and a long arm kit barely noticed the rocks. In fact, that was the recurring theme of the day — the JK was so capable that the trail felt more like a scenic drive than a challenge. Spence noted that when you build a Jeep to this level, you have to drive a lot further (think Moab or the trails in California) to find obstacles that are genuinely difficult.
Testing the Bump Stops in the Real World
One of the goals of this trip was real-world testing of the bump stop setup from a previous Core 4x4 video. With the JK fully flexed in the rock garden, the team got their answer: the rear bump stops were about half an inch from contact, and the back tire had roughly the same clearance. Close, but rubbing.
Spence's take: go with trimming over adding bigger bump stops. Taking a little more material out of the fender is easier and more reliable than chasing bump stop heights. Since the JK was headed for a coilover conversion anyway, the current setup would stay as-is for now — but the data from this run would inform the next build phase.
Forest Lake – More of a Pond, Honestly
After the rock garden, the trail mellowed out and wound through alpine terrain toward the lake. The team pushed through a water crossing, dodged some branches (one caught Spence square in the eye), and eventually reached Forest Lake — which, as Spence pointed out, should really be called Forest Pond.
The GoPro mounted underneath the JK went missing during the water crossing, prompting a brief search-and-rescue mission. They found it on the trail, still recording. The underwater footage made it into the final edit.
What We Learned on the Trail
Every trail run is a testing opportunity for the Core 4x4 team. Here is what this trip confirmed:
- Bump stop clearance: About an inch short on the JK — trimming is the preferred fix over taller bump stops
- Air down matters more than parts: The Tacoma at 24 PSI on 33s could not keep up, while the JK at 10 PSI on 40s rolled through effortlessly
- Sway bar disconnects are essential: The JL with a Rubicon disconnect performed well; the Tacoma without disconnects was limited
- Long arm kits change everything: The JK's long arm setup made the rock garden feel routine — articulation and stability that short arms simply cannot match
- Grease your joints: The JL got a fresh round of grease on arms and end links before hitting the trail — basic maintenance that extends the life of every component
About Forest Lake Trail
Forest Lake Trail is located on the Alpine Loop in American Fork Canyon, Utah. The trail can be accessed from either the American Fork Canyon side (shorter) or from the Heber side via Cascade Springs (longer, about an hour extra). The rock garden is the most technical section and serves as a good proving ground for lifted Jeeps. Beyond that, the trail is scenic but not overly challenging for well-equipped rigs.
Difficulty: Moderate — the rock garden can challenge vehicles with small lifts and 33-inch tires. Locked, long-arm rigs on 37s or larger will find it relatively easy.
Frequently Asked Questions
Shop Core 4x4 Off-Road Parts
Core 4x4 builds adjustable control arms, track bars, and steering components for Jeep, Ram, Toyota, Ford, and Bronco platforms. Everything is manufactured in-house in the USA and backed by a lifetime guarantee. core4x4.com | (385) 375-2104
