The new 2021 Ram 1500 TRX 4x4 pickup is a purpose-built off-road truck with a long-travel suspension and an extremely wide stance. If that sounds familiar, it should because this truck is gunning for the Ford F-150 Raptor. But the T-Rex has two major advantages over the Ford. Its supercharged 6.2-liter Hellcat Hemi V8 makes a stunning 702 horsepower that beats the Raptor's 450 horsepower by a mile. The TRX also benefits from a coil spring 5-link rear suspension that makes strategic use of certain heavy-duty Ram 2500 Power-Wagon running gear components.

The goal of all this factory engineering is to deliver superior stability and composure when hammering along on desert dirt roads with deep whoop-de-doos and washboard. But the same long-travel suspension bits that make it excel on high-speed desert terrain should also allow the rear suspension to flex diagonally in low-speed rock-crawling "frame twist" situations. How much does it flex? That's what we're about to find out.

In this video you'll see me drive the TRX up my purpose-built ramp to see how far it will go before its left rear tire begins to lose traction and leave the ground. This is the point of maximum articulation at which I always stop and take my measurements.

The idea of a Ramp Travel Index (RTI) like mine ramp is simple. It creates an artificial but repeatable frame-twist situation that allows you to safely reach the point of maximum suspension flex and quantify what I prefer to call the Flex Index score. Numerical scores are based on a vehicle’s performance on a 20-degree ramp, an angle that was chosen some time ago. It works well for stock and lightly-modified vehicles, but I'm not sure the TRX counts as lightly modified even if it is an in-house factory off-road suspension.

You can get a detailed walk-through of this suspension by watching another video I made with this same truck: 2021 Ram 1500 TRX Suspension Walkaround - A Better Off-Road Pickup Truck Than The Ford F-150 Raptor? Link:    • 2021 Ram 1500 TRX Suspension Walkarou...  

The TRX has front and rear suspension track widths that are 6 inches wider than a regular Ram. Its 13 inches of front suspension travel and 14 inches of rear travel are a huge step up from the 9 inches found on a regular Ram 1500 4x4. The pounding of the 35-inch Goodyear off-road tires is controlled by specially-tuned coil springs and exclusive computer-controlled and continuously adjustable Bilstein Blackhawk e2 shock absorbers with remote reservoirs and a hydraulic bump stop built inside the ones mounted up front. The Ram’s link-coil rear suspension has been given extra beef in the form of a full-floating Dana 60 rear end that is located by certain heavy-duty components that were adapted from the 2500-series Ram Power Wagon.

Why am I doing this? I can't get enough of this stuff. I'm a former suspension development engineer that worked for years on truck and SUV suspension development projects for two automakers at their remote desert proving grounds. Later on, I somehow stumbled into auto journalism, and for several years I created a popular photo feature called a Suspension Walkaround for Inside Line, a now-defunct offshoot of Edmunds.com (no relation). Today I have resumed writing these features under the name Suspension Deep Dive for Autoblog. Between the two outlets, over 100 of them have been published. Along the way I managed to grow a good-sized fan base, and one question I often heard was, “When are you going to make video versions?”

I never seemed to have the time, the equipment, or the confidence to get in front of the camera, but I got over that by hosting at least 80 professionally-produced videos over three years on the Edmunds You Tube channel. If you like it, please tell your friends, click subscribe, share links, give it a like and check out the other videos on my channel, which is simply called Dan Edmunds. You can also type in the channel’s alias: SuspensionTuna. And I take requests. I can't promise that I can get my hands on any car or truck, but the odds are good. And the more views I get, the more horsepower I'll have when requesting cars to examine.