Description
Lonex L4-A1 Full Gearbox Set (SP100 High Speed Type)
This is a complete, ready-assembled Lonex gearbox in its SP100 High Speed Type configuration. Lonex is a well-known maker of AEG internals, and its full gearbox sets are intended as drop-in replacements for the stock gearbox in M4-pattern AEGs.
The High Speed Type is aimed at players who want a faster rate of fire and quicker trigger response, paired here with an SP100 spring. It suits CQB and fast-paced skirmish players who prefer a snappy, rapid-firing rifle, and is a straightforward way to replace a worn or broken gearbox.
Build and internals
Lonex’s complete M4-A1 gearbox sets are described by retailers as being built on a Version 2 shell with 8mm ball bearings, an enhanced steel gear set, a polycarbonate piston with steel teeth and an aluminium piston head, a steel cylinder, a steel ball bearing spring guide and low-resistance wiring. Because the set arrives assembled, you avoid the time, tools and shimming needed to build a gearbox from loose parts.
Choosing a type
Lonex offers this set in several versions. The SP100 High Speed Type puts the emphasis on rate of fire with a lighter spring, the SP120 Original Type uses a standard ratio, and the SP150 Ultra Torque Type is aimed at pulling stronger springs. A high-speed setup works best with a good battery and a motor that suits it, so it is worth checking your existing set-up before fitting.
Fitting
Swapping a complete gearbox means stripping the lower receiver, so remove the battery and magazine first and note how your existing wiring is routed. Check whether your replica is front- or rear-wired before ordering. After fitting, set the motor height for a smooth, quiet note and test the gun with a chronograph before taking it to a game.
Key features
- Complete, assembled Lonex gearbox set
- SP100 High Speed Type configuration
- Geared for a faster rate of fire
- Version 2 design for M4-pattern AEGs
- Steel gears and ball bearing spring guide (per retailer listings)
- Low-resistance wiring
- Drop-in replacement for many M4 AEGs
Compatibility
Designed for M4-pattern AEGs that use a Version 2 gearbox. Small differences between manufacturers’ receivers mean some bodies may need minor fitting work, and some may not accept it. Check whether your replica is front- or rear-wired, and ask us before ordering if you are unsure which configuration you need.
Care and maintenance
Use good-quality seamless BBs and a battery and motor suited to the gearbox. Fire a shot on semi-auto before storing the gun so the spring is not left compressed. Keep the inner barrel and hop-up clean, and have the gearbox inspected and re-greased if you notice changes in sound, rate of fire or trigger response.
Who is it for?
For M4 AEG owners who want a faster-firing replacement gearbox without building one from scratch, particularly CQB and indoor players.
Please note: Motor, battery and outer parts are not listed as included. Check your power output with a chronograph after fitting and stay within your site’s limits.
