"GOD, THAT MUST take a lot of work!" This is a common reaction among viewers seeing sculptor Cris Bruch's work for the first time. That's certainly not the most interesting aspect of his continuing investigations of material, form, and mass (or lack thereof), but it's true: His work involves big commitments of time and labor. And in his current installation at Suyama Space, Bruch makes that labor the central theme of the piece.

Duty Cycle's main element is a very large wheel, 17 feet in diameter, hanging on a single thin wire threaded through its center and anchored at two spots on the ceiling. Such minimal provisions are made possible by the wheel's material: It is entirely constructed from thick paper. It has a somewhat complex form, tapering from its center to its rim, much like a bicycle wheel. The wheel is assembled in narrow wedgelike sections, one of which has a hole a little bigger than a foot cut out on each side to allow inspection of the inside, revealing that the wheel is mostly hollow. Spoke-like ribs separate the two sides, each with a sequence of large holes cut into them to further lighten the structure. All told, this large object weighs a mere 76 pounds.

It's beautiful, certainly, especially the dizzying views through the wheel's interior. The holes appear to multiply off into infinity, like the view at the corners of a clothing store's triple-mirror array. The near-contradictions the wheel embodies--large and light, thick and hollow--make it a rather intense investigation of the commonplace of the medium of sculpture itself, which is traditionally conceived, as Bruch writes, "on a belief in immanent forms within mass." Indeed, the fiction of a sculpture is often thought to represent the reality of a body or other form within space, displaying the contours of its outermost extensions--of the boundary between object and air--in order to suggest a wholeness.

Bruch's recent sculpture explodes this collusion between form and surface, most clearly in his 1997 paper sculpture Mantel, which has shown at Consolidated Works and the Kirkland Art Center. A large spongelike form in paper, Mantel's open bottom allowed you to peek inside, where the holes on the surface were revealed as positive objects, cones extending toward the interior rather than the voids expressed on the exterior.

Duty Cycle is about work and time. The wheel form suggests time directly, a literal evocation of the wheel of time: the Mayan calendar, clocks, the sun, the moon. Then there's the labor involved. Bruch rejects descriptions of his work as obsessive or compulsive, as "both these terms imply a lack of choice. These pieces are rather about choosing... to submit to what is required by the work." He expresses this choice by using a second element in the piece, an array of buckets with water dripping into them from the ceiling. Cheekily, he suggests that this architect's office has a leaky roof, stringing clear tubes near-invisibly along the ceiling and rigging them to drip, slowly but persistently, into the buckets below. (These metal buckets sound the closest thing to a false note in the installation: Buckets are now made of plastic, and Bruch's use of weathered metal buckets, in a variety of historic styles, lends a fake-authentic Pottery Barn tone to the installation.) These additions represent the other side of Bruch's choice: what he chose not to do in order to devote two months to making this wheel. It's a joke: The committed artist forgot to fix the leaky roof, so his perfect object is accompanied by other, imperfect objects--an imperfect solution to a separate problem.

During my visit last week to Suyama Space, I turned away from the wheel for a while to examine the buckets; when I turned back to the wheel, it was spinning slowly, gracefully, beautifully. I'd seen it sway slightly as people walked past it, but the spinning was new, and, I thought, spontaneous. Actually, a Suyama staffer had merely given the wheel a spin while my back was turned, but before I discovered that, and still somewhat afterward, the wheel had a new aspect of wonder, something beyond explorations of theme and form, something only a very large object or a very small object can easily express: the inexpressible. That's worth two months of labor, right?