Meet the Father of the GMC Hummer EV’s CrabWalk

Mike Colville may be the senior manager of complex feature integration for GMC, but in his spare time he’s a straight shifter. He is also a competitive off-road racer and has created more than a dozen custom vehicles from home. That includes Ginger Chicken, his 4,500-pound build powered by a 700-horsepower V8 and four-wheel drive, which Colville raced for two years at the hardcore King of the Hammers.

Colville brought his vast knowledge and enthusiasm to the GMC Hummer EV; he’s been with the project since day one back in 2019. And now all roads to the new Hummer EV’s CrabWalk lead back to Colville and what he calls “an army” of team members to make it happen.

Mike Colville

Even before he started working on the fast-track all-electric truck, he had experience with mountain tracks that use both front and rear steering from his experiments building off-road vehicles. Four wheel drive is common for people in the mountain climbing world; they duplicate the front suspension on the rear. Although four-wheel steering is not a new technology, the application in the form of CrabWalk is original. Colville realized that the new Hummer had the potential to use the same concept to get through tight turns. Eventually that feature became CrabWalk.

The CrabWalk is stunning in person and conjures up the image of a hippopotamus dancing on tiptoe. By using four-wheel steering to move diagonally, the Hummer EV can adapt to sharp turns that might otherwise be harmful or potentially dangerous. In off-road mode, the rear wheels match the steering angle up to 10 degrees at low speeds, allowing the driver to spin around an object like its namesake crustacean.

Christine Shaw

While Colville had years of senior development engineering roles under his belt, dealing with things like driving noise and vibration, he had also built an impressive resume of software experience. He carved a niche for himself and brought his software influence into his automotive performance job. His role evolved as the person who would ensure that the software was integrated with the hardware to make their dreams of Watts to Freedom and the CrabWalk a reality.

“Josh [Tavel, the executive chief engineer for the Hummer EV] had a ton of automotive performance background, as did program engineering manager Scott Damman,” Colville recalled. “We got access to automotive performance background but no one else really had any software experience. So I became the guy-figure-out-how-to-get-the-software-and-feature-content-to-work-to-make-it-awesome. Software defines vehicles today as much as parts and components, to some extent.”

As the details of the Hummer EV came more into focus, some of the engineers had different ideas about how to accomplish everything they wanted to create.

“I remember Josh slapping my butt a whole lot because his vision was to have a little knob on the dash to flip back and forth to control the rear tires,” Colville said. “But it really takes two brains. We only have one brain.”

They came up with three choices: CrabWalk; auto, which Colville says is the opposite of CrabWalk with a tight turning radius; or off. Then they tuned it for different speeds.

“If you go back to my rock crawling days, if you had the rear steering really twisted and you’re trying to go up a steep hill, bad things can happen very quickly,” Colville said. “The rear of the vehicle will want to come around you and suddenly you’re not going up the hill but across it; that’s not what you want. That’s why the speed of the vehicle comes into it. As the speed increases, the rear tires start to point more straight to provide more stability.”

Colville was convinced that the Hummer EV needed to be legit for the people he was racing off-road with.

Christine Shaw

“All my friends have seen the race cars I’ve built in my garage,” he said. “When people found out what I was working on, they had hopes that it would be cool, but maybe they had doubts. I think we’ve proven all the doubters wrong.”

After spending a couple of days off-roading and on-roading in Arizona last week, I’d say he’s probably right. Even if you think the Hummer EV is a monster that most people shouldn’t trust to drive competently, you can’t help but be impressed. I could see where GMC is reusing technology like the same camera setup that the Sierra debuted a few years ago, and then the features take it up a notch from there. This is a benchmark vehicle and it will pave the way for more innovations from Colville and the rest of the GMC team in the future.

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