RAM Mount’s brake and clutch reservoir bases are one of the most practical and popular ways to mount a phone or GPS on a motorcycle. Instead of clamping to the handlebar, these bases bolt directly onto the existing hardware at your clutch or brake reservoir — keeping the handlebars clean and positioning your device right where you need it. They are especially popular with Honda Gold Wing and Harley-Davidson owners, where handlebar real estate is limited or the aesthetic matters. Built from powder-coated marine-grade aluminum with RAM’s ball-and-socket shock-absorbing technology, these bases are among the most durable motorcycle mounts available.
This guide covers all three versions of the RAM brake and clutch reservoir base so you can choose the right one for your bike and your setup.
How RAM Brake and Clutch Reservoir Bases Work
All three bases attach to your motorcycle in the same way. The reservoir base replaces the existing bolts that hold your clutch or brake reservoir to the handlebar clamp. RAM includes multiple bolt sets — both metric and SAE — along with spacers to accommodate different motorcycles. On a difficulty scale of one to ten, this is about a five. If you are not comfortable working on your bike, a mechanic will likely have seen this installation before and can handle it quickly.
Once installed, each base exposes one or two standard 1-inch B-size RAM balls. These connect to any RAM B-size double-socket arm, which then connects to your choice of cradle — RAM’s X-Grip universal phone holder, a dedicated GPS cradle, a camera adapter, or any other RAM-compatible accessory. The rubber ball sandwiched between the metal arms of the extension absorbs vibration and provides the near-infinite adjustability RAM is known for. For more on X-Grip cradles, see our detailed X-Grip guide here.
Single Ball Base — RAM-B-309-1U
The RAM-B-309-1U is the most straightforward of the three options. It bolts to either the clutch or brake reservoir and exposes a single standard 1-inch B-size ball sitting roughly one inch above the reservoir. Attach a RAM double-socket arm and your choice of cradle and you have a clean, solid mount positioned right at handlebar level. Two sets of bolts, washers, and spacers are included to fit both metric and SAE bikes.
This is the right choice for most riders who only need to mount a single device and want the simplest possible installation. The 1-inch ball is compatible with the full RAM B-size ecosystem — arms, cradles, X-Grips, and camera adapters all connect directly with no adapters required.
Dual Ball Base — RAM-B-309-6U
The RAM-B-309-6U is identical to the single ball base in installation and construction, but adds a second 1-inch ball molded permanently into the base. This is the version to choose if you ever think you might want to mount two devices — a phone on one ball and a Garmin GPS on the other, for example. The second ball is compact and unobtrusive when not in use, so there is no meaningful downside to having it there. Installation is identical to the single ball version.
The dual ball base is especially popular with Harley-Davidson touring bike owners who run both a phone and a GPS, and with Gold Wing riders who want a phone mount on one ball and a camera or action cam adapter on the other. For the small price difference over the single ball version, the dual ball is worth it if there is any chance you will ever use two devices.
Removable Second Ball Base — RAM-B-309-2U
The RAM-B-309-2U is a variant of the dual ball base where the second ball is removable rather than molded permanently into the base. The removable ball installs and removes as needed. Installation and hardware are identical to the other two versions.
In practice, the removable second ball offers little real-world advantage over the molded dual ball version — the second ball on the RAM-B-309-6U is small enough that it does not interfere with anything when not in use. If the option of a completely clean single-ball appearance matters to you, the removable version covers that. Otherwise the molded dual ball base is the simpler long-term choice.
Which Base Should You Choose?
| Base | RAM Model | Balls | Choose If |
|---|---|---|---|
| Single Ball | RAM-B-309-1U | 1 fixed | Mounting one device, simplest install |
| Dual Ball | RAM-B-309-6U | 2 fixed | Mounting two devices or future-proofing |
| Removable Second Ball | RAM-B-309-2U | 1 fixed + 1 removable | Occasionally need a second mount point |
Frequently Asked Questions
Will this base fit my motorcycle?
The RAM brake and clutch reservoir bases fit most standard motorcycles. The hole spacing between centers on your clutch or brake reservoir needs to be between 0.94 and 1.58 inches. Measure your reservoir before ordering if you are unsure. RAM includes both metric and SAE hardware in every kit to cover the widest range of bikes.
What arm and cradle do I need to complete the mount?
All three bases use the standard RAM 1-inch B-size ball. You need a RAM B-size double-socket arm and a compatible cradle. For smartphones, the RAM X-Grip universal holder is the most popular choice and fits virtually any current phone with or without a case. For Garmin GPS devices, use your existing Garmin cradle with a RAM 17mm adapter ball. See our X-Grip guide for full compatibility details.
Is this a difficult installation?
On a scale of one to ten, about a five. You are replacing the bolts that hold your clutch or brake reservoir to the handlebar clamp — straightforward for anyone comfortable with basic bike maintenance, but worth taking to a mechanic if you are not. The key is following the included instruction sheet carefully and using a wrench rather than hand-tightening the bolts.
Is the dual ball base worth it over the single ball?
In most cases yes, given the minimal price difference. The second molded ball on the RAM-B-309-6U is unobtrusive when not in use and gives you the option to add a second device later without replacing the base. If you are certain you will only ever need one mount point, the single ball base is perfectly adequate.
More RAM Mount Guides
- RAM X-Grip Cradles — detailed guide to RAM’s universal phone and tablet holder system
- How to Assemble a RAM Mount — tutorial for assembling your RAM Mount
- RAM 1″ Ball Arms — everything to know about the B-size arms
