So, like Optimus Prime and his Transformer buddies, there is more than meets the eye when it comes to Airsoft AEG gears.  I was once told by a local Airsoft shop owner where I used to live (who is now out of the Airsoft business), that all I needed to do to upgrade my gun was just to install a heavier spring.  This was several years ago, I was brand new to the Airsoft world, and had no clue what I was doing, so I believed him.  Now, however, I know at least one of the reasons why that shop is gone.  He was dead wrong.  He was also a tool, but that's another story for another time.   

One very important piece of the custom Airsoft guns puzzle, is selecting the right set of gears based on the intended use of the AEG they'll be running in. 

You've already seen my babbling on about high-torque gears and some things to watch out for there, now here's a breakdown of the other types of Airsoft AEG gears and their corresponding purposes.

Standard Ratio Gears.

These gears are likely to come installed in most Airsoft AEGs.  They have a gear ratio in the neighborhood of 18:1 to 22:1 or so.  While every setup is going to be different, these gears would probably be best suited for use with 120 & possibly 130 springs, if you were using a high-torque motor as well.

High-Speed Gears.

These gears are best suited for players that wanted to increase their rate of fire.  Generally speaking, players that use these gears in their AEGs are running them on full-auto during games.  Having the increased rate of fire allows the Airsoft "operator" (I use the quoted term extra loosely) to lay down more BBs per second/minute than someone using an identical setup, except with standard ratio gears.

High-speed gear sets utilize fewer teeth than the other gear sets, thus they have the lowest ratios out of all the different types. Lower teeth-counts translate to a faster cycle rate of the piston, and faster piston cycle rates is just a fancy way of saying, "rate of fire" or "ROF" for short.

Some high-speed gear sets not only use less teeth that mesh between the Bevel, Spur, and Sector gears, but they use less sector teeth that mesh with the piston's teeth, requiring the high-speed piston to have less teeth than a standard piston.  This is essentially called short-stroking.  By using less teeth on the piston & sector gear, you're decreasing the distance that the piston has to get pulled back by the Sector gear before it gets released and pushes the burst of air out that's needed to propel the Airsoft BBs toward the bad guys.

High-speed gears generally have a low overall ratio, between 13:1 and 18:1.

If you're serious about going for a true high-speed setup in your AEG, don't half-a$$ it by only getting the high-speed gears.  Get a good motor to go along with it. offers two excellent options in the motor department at the moment: the ICS Turbo 3000 and the SRC Ultra High Torque AEG motors.  Not only do these motors perform well, their affordability factor is just too good to ignore.  Also, make sure NOT to use a metal piston or piston head, as they weigh more than the plastic/polycarb pistons and will not only reduce your AEG's power a bit, they'll slow down your ROF.  Also, use gearbox bushings that have the little ball bearings in them instead of the solid metal bushings (make sure you know the diameter of the bearings that your gearbox uses).  Those are better suited for high-torque setups, which we will dive in the next installment or two.  Perhaps one of the more influential parts affecting your ROF is the spring strength.  You CAN have a high-speed, high-torque setup, but plan on dropping LOTS of coin and tearing your gun down OFTEN to repair and replace broken parts.  If you just want a high-ROF AEG shooting 400 FPS or less, you'll not want to run more than a 120 spring in your rifle.  The lighter the spring's strength, the higher the AEG's ROF will be, assuming all other appropriate parts have been installed.

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