RAM makes great mounts. Excellent quality with hundreds of custom options (they have custom cradles for Garmin, TomTom, Magellan and many tablets). But their selection can sometimes be confusing. We wrote this post to help explain how their numbering (and lettering) system works. Some of this information can be found on their web site if you know where to find it. For those looking for the executive summary on RAM Mounts, we thought it would be helpful to provide a brief explanation.
The RAM Mounts system is a simple ball and socket design. You need to make sure the ball size matches the socket. The majority of RAM mounts sold for cameras, GPS, Phones and Tablets are one-inch balls (RAM-B or RAP-B). Most use the metal (the M in RAM-B) but to save a few dollars, some will opt for the plastic (the P in RAP-B).
Arms typically come in several sizes too. Again most common is the one inch ball, and there are three arm sizes (1.75, 3 and 6 inch sizes). Most of our mount listings have an option to choose an arm size.
Here is the RAM Mounts high level numbering system and arm sizes in detail:
A size ball = .56″ diameter (seldom used)
B size ball = 1″ diameter (by far the most common)
C size ball = 1.5″ diameter (used for heavier items like marine electronics)
D size ball = 2.25″ diameter (very seldom used)
E size ball = 3.38″ diameter (very rarely used)
The size ball you select will likely be determined by the weight and size of the device you are mounting. The manufacturer likes to recommend the standard one inch ball for devices that weigh up to five pounds. That covers most cameras, phones, tablets and GPS units as they seldom exceed one pound. The 1.5 inch ball is typically recommended for applications up to 10 pounds and also where more rugged use will take place. We always like to use a 1.5 inch ball on the water since boats have a tendency to move around a lot plus most marine electronics are fairly heavy. The 2.25 inch ball is normally used for devices to 15 pounds. We often see that size ball used with the larger marine electronics like the Lowrance HDS-10 series. Have never seen the E-size ball used and it’s like the size of a baseball.
Always keep in mind that the base mount can typically be reused for other devices. For example, you wish to use the mount to hold your Samsung Galaxy S7 today, and tomorrow want to use it to hold an iPad Mini, it’s a simple matter of changing out the cradle. We always recommend buying an extra adapter ball. That way, you don’t need to fuss with a screwdriver each time you change out the device. The mounts have a lifetime warranty too, so if there’s a problem, RAM will replace it. They typically ask for a photo of the damaged component as evidence of the problem and charge a small shipped fee for the new component.
We have written several good articles on RAM components. If you would like to read about the RAM X-Grip cradles, here’s an excellent article on the topic. An article on RAM extensions might help if your current mount is too short. A good article on RAM motorcycle mounts is also available.