What the package includes
- Padded bench seat that bolts to the rear deck
- Foot pegs or running-board style supports for the passenger
- Protective skirts to keep feet and cargo clear of the wheel
Rules of the road
Respect the total payload rating printed in the manual: rider plus passenger plus cargo. Passengers change braking distances and low-speed balance more than their weight suggests; the step-through RadRunner geometry helps, but practice unloaded corners first. Check local law on passengers, minimum ages and helmet rules; jurisdictions differ.
Child seats
For small children, a purpose-made child seat (Rad partners with mainstream child-seat brands for deck mounting) beats the bench: harness, head support and foot containment matter more than padding. The deck's rating accommodates them comfortably.
Bolting it on properly
The package is deliberately simple to fit, but the details matter because a person sits on the result. Torque the deck bolts snug and even, then re-check every fastener after the first week of loaded riding; new hardware settles. Align the wheel skirts with clear space to the tire on both sides, and confirm the pegs are tight enough that a standing passenger cannot rotate them. Keep the leftover hardware in a labeled bag; passenger setups come off for cargo season and go back on later, and missing spacers are the usual casualty of the second install.
Two-up habits the manual undersells
- Rider first, brakes held, then the passenger mounts; reverse the order to dismount.
- Passenger feet stay on the pegs at stops; a foot going down at the wrong moment tips more bikes than corners do.
- Start in a lower assist level so launches stay smooth with the extra load.
- Run tire pressure toward the higher end of the sidewall range when riding loaded.
- Agree on a no-sudden-movement rule; a passenger leaning opposite to you in a corner fights the bike.
What wears faster with a passenger aboard
Owners running regular two-up miles report the same list: brake pads go noticeably faster, so check them on a schedule you would previously have considered paranoid; spokes settle under the extra load, worth a tension check in the first month of passenger duty; and tires square off sooner, especially the rear. None of this is a defect, just physics billing you for the second seat. The drivetrain also works harder on starts, so keep the chain clean and lubricated. Budget the maintenance and the RadRunner does two-up duty without complaint; skip it and the bike gets loud about the neglect.