Field notes
The 1-Inch Ball System, Explained
Every mount on our motorcycle shelf is three parts talking to each other through a rubber ball one inch across. Learn the three parts, and you can build a mount for almost anything you own.
Part one: the base
The base is the only part that touches the vehicle. On a motorcycle it is usually a rail base that wraps a round handlebar between 22.2 and 32 mm. On quads, side-by-sides, kayaks and roll cages, where tubes come in every shape, a claw clamp takes over. If your cradle already has the four-hole AMPS pattern, a plate with a ball on it becomes the base on the device side.
- Motorcycle Handlebar Rail Base with 1″ Ball — The foundation piece: a round-bar clamp topped with a rubber 1″ ball.
- Tough-Claw Small Clamp Base with 1″ Ball — Just the claw and the ball — for phones, cameras, rod holders or a GPS.
- Metal Rectangular AMPS Plate with 1″ Ball — 2″ × 1.7″ aluminum plate that bolts a ball onto any AMPS cradle.
Part two: the arm
The double socket arm has a socket at each end and a knob in the middle. Loosen the knob and both sockets relax, so the device can swing around either ball; tighten it and everything locks. A short arm keeps the screen close to the bar and cuts vibration — ours is 2.38 inches overall.
- Double Socket Arm 1″ B-Size — 2.38″ overall, one knob, two sockets: the joint that sets every angle.
Part three: the holder
The holder carries the device. For Garmin handhelds with a spine on the back, a spine clip holder does the job. The Montana 700 series has its own holder, and a zūmo XT dock bolts to an AMPS plate.
- Spine Clip Holder with 1″ Ball for Garmin Handhelds — Turn any ball-mount setup into a home for a spine-mount handheld.
- GPS Holder with 1″ Ball for Garmin Montana 700 Series — The cradle alone: drop a Montana 700 onto any B-size arm you already run.
- Metal Rectangular AMPS Plate with 1″ Ball — 2″ × 1.7″ aluminum plate that bolts a ball onto any AMPS cradle.
Three rules we ride by
- Match the ball. Every part here is B-size, 1 inch. Do not mix it with 1.5-inch C-size parts.
- Keep it short. The shorter the arm, the less the screen shakes.
- Route the cable last. Use the grooves on the arm and leave a small loop for steering lock.