The primary difference between the REVO, REVO-A, and REVO ARC is the amount of adjustment and tunability offered with each shock. We'll begin by first discussing the differences between the REVO and REVO-A:

The main difference between the REVO and the REVO-A is the rebound adjustment option offered on the REVO-A. 

On our REVO line, we designed them to be user-friendly without requiring a degree in engineering to adjust them and enjoy them. One of the things that we’ve done to achieve this and offer a great ride is actually going to a lighter spring rate by installing a 2” longer coil with a lighter wire diameter. This allows the shock to have a wide range of adjustability and to be very compliant throughout the range of travel. Shorter springs with a larger wire diameter tend to have a much higher rebound rate as the shock is compressed, resulting in a jarring effect even on smaller bumps and normal road conditions. Keep in mind, there are no disguising deep potholes and such with only three inches of travel, it doesn’t matter if it’s Legend shocks or any of the competition. But under normal conditions, expansion joints, bridge joints, railroad tracks, manhole covers, drain basins, etc. …your normal everyday road hazards shouldn’t beat a rider up. This directly falls in line with the initial setup of our shocks and adjusting the sag setting properly to your weight to keep you off the bump stop.

The REVO-A has all the capabilities that the REVO has but it also offers the ability to control and adjust the rebound. This is controlled by the Rebound Adjuster Knob. The adjuster on our shock is very easy to use, basically there are six settings that can be selected with #1 being the softest and quickest reacting and #6 being the firmest and slowest reacting. The dial can be turned 360 degrees infinitely clockwise or counterclockwise, with a small detent at each number that you can feel lock-in. It is just a matter of selecting the number you want by lining it up with the index mark on the bottom of each shock, there is no counting the number of turns or counting clicks. There is no magic setting on this dial because everyone has a different feel about what they are looking for. So we made it easily tunable, so based on what you’re feeling thru the seat of your pants and in your back, you can make that adjustment.

While the REVO-A's are no slouch, the REVO ARC's are the next level of performance and comfort, even though there are some similarities between them (spring rates offered, and spring length), here are the most notable differences:

• REVO ARC offers 7 External knob adjustments for fine-tuning the compression (compression adjustment is not available on the REVO-A)
• They have 7 External knob adjustments for fine-tuning the rebound (the REVO-A only has 6 rebound settings)
• 35MM Monotube construction and nitrogen charged (REVO/REVO-A have a 25mm twin tube design)
• 13" REVO ARC's have 3.5" of travel (13" REVO/REVO-A have only 3" of travel due to twin tube design)
• Nitrogen gas bladder design allows for ultra-fast response and stiction-free movement (REVO/REVO-A have a low-pressure gas bag due to twin tube design)

What does this mean to you? Overall they have more travel, more adjustments, and a larger range of tuning. You can tune them for comfort or for performance, depending on what type of riding you're planning on doing that day. An example of this is to open the compression (5-7 clicks) and rebound adjusters (4-6 clicks) for straight-line comfort, then close the compression (2-4 clicks) and the rebound adjusters (1-3 clicks) for the days that you want to go drag floorboards on twisty canyon roads.

Regardless of the shock model you choose (REVO, REVO-A, or REVO ARC), you won't be disappointed and will notice a significant improvement in ride quality and suspension performance, it is just up to you how much adjustability you want.