What Is a Portal Gear Lift?

Lift and Gearing, Delivered at the Hub

A portal gear lift is a set of four gearboxes, one at each wheel hub. Inside each box, a gear train does two jobs at once. First, it drops the wheel's centerline below the axle's centerline — the wheel literally hangs lower than the axle driving it — and that offset is lift: 4 or 6 inches of it, gained without touching the suspension's geometry, angles or ride. Second, the gears reduce the final drive at the wheel itself, so the engine turns more times for every tire revolution. That reduction is the real prize. Big tires effectively gear a machine taller and steal its low-end pull; a portal puts the gearing back at the exact place the big tire took it away, while also moving the stress of turning that tire out of the transmission, belt and axles and into a steel gear set built for it. It is the only modification that makes a machine taller and stronger-geared at the same time.

The Numbers on Our Listings

Every SuperATV GDP kit in this store is configured the same three ways, which makes the lineup easy to read. Reduction: 4-inch kits offer 15% or 30%; 6-inch kits offer 30%, 45% or 60%. More reduction turns a bigger tire and gives up more top speed doing it — match the percentage to the tire jump, not to your enthusiasm. Housings: cast or billet aluminum, and on some kits a choice of single or dual idler gears. The 4-inch ladder is consistent across the catalog: cast $2,574.95 · billet $3,574.95 · dual-idler billet $4,016.95 — read it off the RZR XP 900 4-inch kit or the Teryx 4-inch kit. The 6-inch line, like the Yamaha Viking 6-inch kit, runs $2,976.95 in cast, $4,016.95 in billet and $4,624.95 in dual-idler billet. One honest width note, straight from our listings: a 4-inch kit adds about 4 inches of width per side, because the gearboxes live outboard of the hubs. Check your trailer and your trails with that number in mind. Our current GDP lineup runs 4-inch and 6-inch kits; the full machine list is the portal lifts collection.

Who Actually Needs Portals

  • The mud rider going to 35s and beyond. This is the textbook case: the lift clears the tire, the reduction turns it, and the hub gears survive what would eat axles. Pair this page with the mud tire guide and you have the whole build.
  • The rock crawler who wants clearance without a tall, tippy suspension lift. Portals raise the chassis while the suspension stays at its designed ride height, and the reduction is low-speed torque — the two things crawling actually asks for.
  • The work machine on oversize tires. A Defender or Ranger that went up in tire size for ground clearance and lost its pulling manners gets them back at the hub. Our Defender and General kits are among the most-asked-for in the collection.
  • Not you, if: you are staying near stock tire size, you ride fast desert where top speed matters more than reduction, or your budget is headed for tires first. Portals are the answer to a problem big tires create; without big tires, there is cheaper fun to have — start with the tire sizes by machine guide.

Choosing Your Kit

Three decisions. Height: 4 inches covers most 35-inch builds and keeps the machine's manners; 6 inches is for dedicated mud builds on the tallest rubber. Reduction: as a working rule, pick the percentage closest to your tire-size jump — going from a 30 to a 35 is roughly a 15–17% jump in diameter, so the 15% and 30% kits bracket most real builds, with 45% and 60% reserved for the biggest 6-inch setups. Housing: cast is the value pick and carries most riders; billet is for high-horsepower machines and anyone who plans to be buried axle-deep weekly; dual idlers spread the load further on the hardest-used kits. Fitment is machine-specific down to the year — browse the portal lifts collection for your machine, and if you want the gearing math checked against the exact tires you are planning, contact Dirti Motorsports before you order. That is a conversation we would rather have before the build than after it.