Kneeling systems on wheelchair minivans: what they do for the ramp

What the kneel does

Kneeling is the lowering of a converted van’s rear suspension so the ramp lands at a shallower angle. It works together with a lowered floor: the floor drop makes room for a seated rider, and the kneel takes a few more degrees off the climb at each stop. What else a conversion changes is in the wheelchair van conversion guide.

On a power-ramp minivan, the kneel is part of one sequence. BraunAbility’s Pacifica power foldout manual describes an electrohydraulic rear suspension that starts lowering the moment the sliding door starts to open, and starts rising as the ramp begins to stow. A kneel on/off switch on the center console decides whether it runs at all. If the driver turns the switch on during the opening sequence or within 60 seconds of the ramp coming out, the van kneels once the ramp is fully deployed. VMI calls its version PowerKneel and describes it as automatic suspension lowering.

Full-size vans can kneel too. Driverge’s rear-ramp system for the Ram ProMaster, for example, lowers the back of the van with a hydraulic kneel.

How much flatter the ramp gets

On current side-entry minivans, the kneel takes the ramp to roughly 9 degrees:

• VMI Toyota Northstar. 12 degrees without the kneel, 8.8 degrees with PowerKneel.
• BraunAbility Toyota Sienna Power Foldout XT. 9 degrees kneeled, on a 52-inch ramp.
• BraunAbility Honda Odyssey power in-floor. 9.2 degrees kneeled, also on a 52-inch ramp.

BraunAbility’s Sienna figures assume a 250-pound load placed mid-ramp and may vary by 1.5 degrees with trim level and conditions, so treat any listed angle as approximate.

The federal ramp rule for accessible vans, 49 CFR 38.23(c), asks for the least slope practicable and caps a ramp deployed to the ground at 1:4, which is about 14 degrees. A kneeled minivan at 9 degrees sits close to 1:6, about 9.5 degrees. The gentler limits that apply when the ramp lands on a curb are listed in the ADA requirements guide.

The difference shows up in the driver’s arms. The downhill pull of a chair on a ramp grows with the sine of the angle, so at 12 degrees it is about 36 percent larger than at 8.8 degrees. As an example, a 400-pound power chair and rider pull back with about 83 pounds of force on a 12 degree ramp and about 61 pounds at 8.8 degrees, before rolling resistance. The same arithmetic shows why a little height matters: on a 52-inch ramp, every inch of floor height adds a little over 1 degree.

When the van should stay at full height

The kneel is for street-level boarding. Two situations call for the van at its normal height:

• Tall curbs. At a curb of 4 inches or more, VMI’s 2026 Northstar manual has the kneel switched off before the ramp comes out, to protect the ramp. The curb already shortens the climb.
• Driving. The van has to be back at ride height before it moves, and BraunAbility also advises against leaving it lowered for long stretches. Its controls raise the van automatically if the transmission leaves Park with the ramp out.

A kneel that will not lower or rise has its own faults and an override switch, covered in the guide to a wheelchair van ramp that is not working. The kneel mechanism also has its own service items and battery load, covered in the manual vs power ramp and battery drain guides.