The standard Chevrolet Colorado doesn’t stand out from the crowd, but the ZR2 is a serious off-road version that is a completely different animal. That emblem signifies that a real off-road optimized suspension is present, but the Colorado ZR2 isn’t a brand-new idea. In the 1990’s Chevy’s smaller S-10 pickup could also be bought with the ZR2 off-road option.
In both cases the formula is the same: add a significant suspension lift, fit longer control arms and broader axles to substantially widen the track, and swap in special off-road-tuned shocks and fit larger 31-inch all-terrain tires that are better able to cope with harsh off-road terrain. The S-10 ZR2 rode on Bilstein dampers and BFGoodrich tires, while the new Colorado ZR2 employs is fitted with exotic Multimatic DSSV dampers and Kevlar-reinforced Goodyear Wrangler Duratrac tires.
In this video you’ll see me pull those tires off so we can all take a detailed look at the suspension up close, and then I’ll bolt them back up and run the Colorado ZR2 up my Ramp Travel Index (RTI) ramp. The idea of an RTI 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 call the Flex Index score through a simple measurement. Numerical scores are based on a vehicle’s performance on a 20-degree ramp, an angle that was chosen some time ago and works well for stock vehicles.
It’s worth noting that this particular Colorado ZR2 is fitted with the Bison package that was co-developed by GM and American Expedition Vehicles (AEV). AEV caters to the overlanding crowd, and their package of upgrades includes functional upgrades such as stronger wheels, front and rear bumpers that offer greater protection from trailside rocks, and a couple of additional skidplates. The front bumper is winch-capable, too. The suspension that we’ll see, however, is common with ZR2s that do not have the Bison package.
Why am I doing this? I love this stuff. I'm a former suspension development engineer that spent most of my career developing off-road focused trucks and SUVs. Later, I somehow found my way 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. I'm also doing video versions here on this channel.
But I'm also known for a series of RTI blog posts and Instagram shots featuring numerous off-road vehicles posing on this very RTI ramp. I didn't know where to buy such a ramp when I first got interested in doing this, so I designed one myself, bought all the metal, cut it to size, and had a friend of a friend weld it together. My previous employer was tired of it being in the way, so it's now with me at home, where I'm starting to re-build my database with new vehicles. I'll be keeping track of everything I measure and will be calling my database the Flex Index.
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 the last three years on the Edmunds.com You Tube channel. If you like this video, 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. And I take requests. I can't promise that I can get my hands on every new off-road oriented truck or SUV, but the odds are good. And the more views I get, the more horsepower I'll have when requesting off-road vehicles to examine.