RAM ATV/Side By Side Rail Mount with Camera Stud Base (1/4"-20)
Turn any tripod-thread camera into a hard-mounted cab camera — base, arm and a universal stud plate in one kit.
This is the same RAM-B-149Z-2 rail base and arm as above, finished with a round 2.5" (63.5 mm) diameter plate carrying a male 1/4"-20 threaded steel stud — the same standard tripod thread found on the base of almost every camcorder and digital camera. If a camera or action-cam accessory can screw onto a regular tripod, it can screw onto this.
What's in the kit
In the box: strap clamp adapter, two U-bolts (0.5"–1.25" rails), a B-size medium double socket arm (3" socket-to-socket), and the camera base itself — a 2.5" (63.5 mm) round plate with a centered 1/4"-20 threaded steel stud that provides broad, stable support under the camera. As a bonus, the same plate is also drilled to a 4-hole AMPS pattern (1.181" x 1.496") and a 3-hole 120-degree pattern (1.812" diameter), so it can alternatively carry an AMPS or 3-hole accessory instead of a stud-thread camera.
Made of powder-coated marine-grade aluminum and high-strength composite; the stud is steel.
How RAM's modular system works
Every RAM product on this page is part of the same modular system used across RAM's entire catalog. Once you understand how it fits together, every other RAM accessory we sell will make sense too.
- A base — clamps, bolts, or straps onto the vehicle (a rail, a roll bar, a dash, a windshield, or a device's own housing).
- An arm — connects two RAM balls together. It can be locked at any angle, so once mounted you can tilt, rotate, and reposition the device freely, then lock it firmly in place by hand.
- A cradle or holder — grips the specific device (tablet, phone, GPS unit, camera).
The ball size determines what it can carry. RAM uses five ball sizes, each rated for a different weight/duty class:
| Ball size | What it's for |
| A Size | Rarely used; costs more to make than B Size but carries less. Reserved for small, low-profile items like security cameras. |
| B Size — used on this product | RAM's most common size, standard duty. Recommended for phones, GPS units, and light tablets in normal use. |
| C Size | Heavy duty. Used for larger tablets, handheld computers/scanners, CB radios, and anything mounted somewhere with a lot of vibration or shock — exactly the case in a tractor, ATV or UTV cab. |
| D / E Size | Reserved for large monitors and specialist/military equipment; rarely needed outside those cases. |
Rule of thumb: if the mount will live somewhere that's frequently jostled, vibrated, or under constant load — an off-road vehicle like a tractor, ATV or UTV — RAM recommends stepping up to the larger ball size (C rather than B) for extra stability, even if a lighter mount would technically hold the device's weight.
No tools required, on purpose. RAM arms are designed to be tightened by hand only — there's no official torque spec, because the ball-and-socket joint is meant to be adjustable in the field without a wrench. If hand-tightening doesn't hold your device firmly, that's usually a sign the ball size is undersized for the device — sizing up solves it, rather than over-tightening.
Aluminum or composite — both are built for the outdoors. RAM mounts are made from marine-grade aluminum or high-strength composite, interchangeably depending on the product; both carry a lifetime warranty and similar weight ratings. Aluminum's powder-coat finish handles rough vibration and shock slightly better; composite skips the paint entirely, so it has nothing to chip and is often preferred in high-corrosion or salt-air environments. Neither choice is worse — it's a trade-off between finish and environment.
Specifications
| Ball size | B Size (1" / 25 mm) |
| Arm length | Medium, 3" socket-to-socket (76 mm) |
| Camera stud thread | 1/4"-20, male, steel |
| Camera plate diameter | 2.5" (63.5 mm) |
| Alternative hole patterns | 4-Hole AMPS 1.181"x1.496"; 3-Hole 120°, 1.812" dia. |
| U-bolt clamp range | 0.5"–1.25" (12.7–31.75 mm) |
| Strap clamp range | 1.57"–3.15" (40–80 mm) |
| Weight capacity, standard use | 2 lbs (0.9 kg) |
| Weight capacity, heavy-duty use | 1 lb (0.45 kg) |
| Materials | Marine-grade aluminum, high-strength composite |
| Included | Complete kit: base + arm + camera stud plate |
| Warranty | Lifetime warranty |
Frequently asked questions
What cameras fit this mount?
Any camera, camcorder or action camera accessory with a standard female 1/4"-20 tripod thread on its base — the same thread used on nearly all consumer cameras and tripod quick-release plates.
Is this a complete mount, or do I need anything else?
It's complete — rail base, arm and the camera stud plate are all included. Clamp it to a roll bar or rail and thread your camera onto the stud.
Can I use a different cradle instead of the camera stud?
Yes — the same round plate is also drilled to a 4-hole AMPS pattern and a 3-hole 120-degree pattern, so accessories that use either of those patterns can be bolted on instead of using the stud.
Why B size for a camera mount?
Most cab and action cameras are light and compact, which is comfortably within RAM's standard-duty B-size rating. If you're mounting a heavier camera setup, consider RAM's C-size hardware instead.
How wide a rail does the base clamp onto?
U-bolts for 0.5"–1.25" (12.7–31.75 mm) diameter tubing, and the strap clamp for 1.57"–3.15" (40–80 mm) diameter rails or bars — the same range as the other RAM-149Z-2 kits above.
Not sure which RAM combination fits your tablet, phone or GPS unit? Contact us and we'll help you put together the right base, arm and cradle.