Suzuki DR-Z4SM Track Riding: K1 Circuit Supermoto Test

It is a beautiful morning in Southern California, and we are skipping the morning traffic to head straight to the candy store. Our objective? To take the heavily updated, street-legal Suzuki DR-Z4SM out of its urban element and throw it directly onto a tight, twisting asphalt playground: the brand-new K1 Circuit facility out in Winchester, California.

Yesterday was all about exploring local backroads to gauge its daily manners. Today, we are mounting up an Insta360 follow-me camera rig, airing down the tires, and turning up the heat on a professional-grade, 5,280-foot outdoor kart track.

The Recipe: Modern Tech on a Legendary Supermoto Platform

For over two decades, the original DR-Z400SM formula leaned heavily on carbureted simplicity and bulletproof durability. The updated generation turns a massive page. While it proudly carries forward its signature single-cylinder character, Suzuki injected a heavy dose of modern refinement into the package.

Related: SoCal Supermoto School Review

The headliner here is the thoroughly revised 398cc DOHC liquid-cooled engine, which finally swaps out the old carburetor for an electronic fuel injection system running a 42mm ride-by-wire throttle body. The frame is an all-new twin-spar steel design paired with a lightweight aluminum subframe. Rolling on classic 17-inch spoked wheels, it comes shod from the factory with ultra-sticky Dunlop Sportmax Q5A rubber.

On paper, a 340-pound curb weight might give hardcore supermoto purists pause. But out on the asphalt, the bike carries its mass exceptionally low, creating a planted, predictable feel that begs you to push harder into every apex.

K1 Circuit: Burning Asphalt on a One-Mile Pro Track

The K1 Circuit facility features nearly a full mile of complex elevation changes, high-speed sweeps, and tight, hair-raising switchbacks. It is the absolute ultimate test for a mid-sized supermoto.

Before dropping the hammer, we caught up with some fellow riders in the paddock to talk styling and presence. Suzuki’s minimalist bodywork, updated LED lighting, and striking Sky Gray livery give it an aggressive, contemporary look. It balances a high-performance attitude with approachable ergonomics—though the 35.0-inch seat height means shorter riders will be stretching at a standstill.

Once out on the asphalt, the new Suzuki Intelligent Ride System (S.I.R.S.) proves its worth. The throttle response is crisp and infinitely more linear than the old model, completely eliminating any of the low-end bog associated with older singles. The bike features switchable ABS, allowing advanced riders to disengage the rear anti-lock intervention entirely to back the rear end gracefully into tight corners.

The KYB inverted front forks and link-type rear shock keep the chassis remarkably stable under heavy braking. Coming down the main straight, grabbing a handful of the 310mm front disc brake provides excellent initial bite without inducing excessive front-end dive.

The Verdict: More Personality Than Ever

Is the new DR-Z4SM a purebred, fire-breathing race machine? Not quite. But what it lacks in raw, intimidating horsepower, it more than makes up for in pure, unadulterated personality. It strikes a fantastic middle ground in the current market, coming in significantly more affordable than European heavyweights like the KTM 690 SMC R while offering a much more robust electronics suite and performance ceiling than smaller entry-level options.

Whether you are seeking a bulletproof daily commuter to slice through city traffic or a weekend weapon to tear up local kart tracks, Suzuki has successfully modernized an icon without losing the playful soul that made it famous.

Suzuki DR-Z4SM Specifications