by Moondog
Full Video Review:
http://www.youtube.com/watch?v=2DF4mfiMDlw
Synopsis
The Matrix 210% is an excellent upgrade spring designed to match the qualities of the PDI-210 (equivalent of an M-135 class spring.) Both offer 210% of the power of an original Tokyo Mauri spring.
Both feature variable pitch coils (the coils on part of the spring are closer together than the coils on the rest of the spring) which allows the spring to function like two springs. One set of coils offers the stiffness and power to propel a .20g BB in excess of 430fps, while the other set of springs are soft, acting as a shock absorber when the piston slams into the piston head. The major differences are that the Matrix 210 spring features chromed metal which should provide long-term protection against oxidation. The second is that the Matrix is cheaper.
Installing this spring may require you to upgrade other parts of your gearbox such as the motor and gears. Stock Tokyo Marui's and older DBoys and A&K gearboxes will not be strong enough for this upgrade. Classic Army and 2008 or later model JG, CYMA, and DBoys gearboxes should be ok, but will still likely require you to upgrade to a high-torque motor. Stronger springs put much more stress on parts and will cause more frequent gearbox breakages and shorter battery life because your motor requires more juice to pull a harder spring.
Be advised that your FPS will exceed 420fps w/ 0.20g BB's with this spring installed. This is higher than many fields allow. AEG's with this spring should only be used on fields with 400fps w/ 0.25g BB's limits (which is Approx. 433fps w/ 0.20g BB's). Cheating with BB weight is still cheating and should not be tolerated.
