SDL1

For the motorcycle in Earth Defense Force 5, see Free Bike The SDL1 is a vehicle that the Air Raider can call on in Earth Defense Force 2025 and Earth Defense Force 4.1: The Shadow of New Despair. It is not particularly likely that they will.

Description
The smallest vehicle the Air Raider can call upon (unless exploding Roombas are counted as vehicles), the SDL1 is a high-powered sport motorcycle fitted with a sidecar that mounts a surprisingly potent machine gun. The driver has no weapon, and it is necessary for another player character to get in the gunner's seat to drive and shoot at the same time. Only a Ranger or Air Raider can drive an SDL1, though any class can ride in the sidecar. It is the fastest vehicle in either game, though this is something of a double-edged sword in practice.

According to the vehicle's description, it is an old model that pre-dates the EDF's advanced "air injection" SDL2 Airbike seen in Monster Attack, Global Defence Force and Earth Defense Force 2017. The latter apparently suffered from "numerous issues" that prevented it from being retained after the 2017 war, including low durability. Precisely how these issues were worse than the ones the SDL1 itself has is unclear.

In EDF 4.1 it is improved (?) by giving the Air Raider the ability to summon more than one at a time: two with most models, and three with the level 18 version. The player can "reload" the SDL1 drop using the standard reload button to skip deployment of any remaining bikes and move to accumulating credits for a new set. It is also one of only two vehicles that can now be summoned in underground levels, the other being the new Depth Crawler. Deploying a new SDL1 underground will summon it instantly on the exact spot where the grenade landed; it simply appears magically in a puff of smoke.

Strategy
Don't use it.

Actual Strategy
Getting the SDL1 to actually go anywhere without flipping over or blowing up is a challenge in itself as it is the only ground vehicle that loses health from collisions with terrain, something that normally only occurs with helicopters. It is also realistically off-balance as a motorcycle mounting a heavy sidecar would be, which means it tends to pull to the left. With the final model, starting it without the front wheel rising up to the point it rolls over completely means the player is doing well.

The trick to handling an SDL1 is to gently ease the analog stick forward, treating it like a throttle; with some care the SDL1 is merely incredibly hard to control. In the PC version of EDF 4.1 it is thus basically impossible to drive one using the keyboard.

If the player suddenly acquires wizard powers and can actually move the vehicle around successfully, there are some interesting strategies that it can potentially be employed for, such as darting in and using the Air Raider's demolition charges on Tunnel Exits while their occupants are busy engaging in combat elsewhere with other players, escaping pursuing bugs for long enough to jump out and reload turrets before they catch up, or rushing to revive downed team members or place Life Vendors or other support equipment with a besieged ally.

Assuming that an Air Raider decides to take an SDL1 and gets it somewhere it needs to be without destroying it, it can actually throw out significant damage. The final SDL1 Burst Turbo's gun deals twice as much damage per shot as even the top-level ZEXR-Gun turret: it also has a 50% higher rate of fire than one ZEXR-Gun and 140% more ammunition. Since the Air Raider can have two SDL1 Burst Turbos in place at once in 4.1, summoning both in a chokepoint with another player present is actually superior to placing three turrets.

This high damage but terrible movement means that unless the player using it has invested a significant amount of time and magic learning to drive the SDL1 (in which case they would probably not need to read this) it is best to treat it more like a deployable machine gun nest than a vehicle.

However, it should be noted that the early models' machine guns are identical in terms of damage and fire rate to the secondary heavy machine guns of a near-level Epsilon Armored Railgun, though the SDL1's gun has 20% more ammunition than both of the Epsilon's put together, and a 20 metre range advantage. The SDL1's damage is exactly the same as the level 10 Epsilon, and the SDL1 Bike's the same as the level 19 Epsilon D. Later the Epsilon pulls ahead in this regard; the Epsilon ME2 does 31 damage instead of 30, the Epsilon Blast does 90 instead of 63, and the final Blast E model 150 damage instead of 132. It should also be noted that the Epsilon can fire both machine guns at once for double the effective fire rate of the SDL1, and the Epsilon Blast E also has nine times the health of an SDL1 Burst Turbo.

And a railgun.

Therefore, the SDL1 is best used as an underground deployable machine gun nest. It is left as an exercise to the non-wizard reader as to what to do with it in EDF 2025 where it cannot be deployed underground.

Variants
All SDL1s have a crew capacity of 2 and reload for 1,000 credits. The "number of requests" column only applies to EDF 4.1, and in 2025 only one can be requested at a time as with other vehicles.

Trivia

 * "SDL" probably stands for "Suzuki DL" which is part of the model number of the Suzuki V-Strum series of sports motorcycles.
 * The curiously named "SDL1 Bike" (what exactly was the first one?) is called the "SDL1 Bike Custom" in the original Japanese version. It is not clear why "custom" was omitted in the translation.