Increases sentry fire rate appreciably
~ BTD5 & BMC in-game description

A monkey engineer with the sprockets upgrade.

Increases sentry gun and Engineer attack speed.
~ BTD6 in-game description

Bloons TD 5 & Bloons Monkey City:

Sprockets is a tier 3 upgrade for the Monkey Engineer's second upgrade path. It increases the attack speed for sentries and the Monkey Engineer's nail gun. By getting this upgrade, the tier 3 upgrade in the first path cannot be purchased. Sentries that belong to Engineers with Sprockets become SentrySprockets (named in BMC Flash only), if at least the Sentry Gun upgrade is bought. It increases the attack speed for the Monkey Engineer's nail gun by roughly 25% and the sentries by ~50%.

Bloons TD 6:

Sprockets is the 3rd upgrade of Path 1 for the Engineer Monkey. It increases the attack speed for sentries and the Monkey Engineer's nail gun by 67%.



  • Adding Sprockets can allow the whole Engineer and his sentries to easily solo versus rounds with lots of Yellows and/or Pinks, where normally other sentry-based Engineers would struggle.

Version History (BTD6)Edit

12.0 (Engineer update)

Nerf Pierce of Sentry Gun decreased (2 --> 1)

  • Buff Standard Sentry pierce increased from 1 to 2



BMC Sprockets error

The helmet-switching mistake from the Sprockets upgrade in BMC Flash

  • The official artwork has a mistake in it; the Engineer's helmet is red. At the same time, the Larger Service Area upgrade's official artwork has the black helmet from this upgrade.
  • This upgrade also increases range, as it's notable under Monkey Village's influence.
  • The BTD5 Artwork shows that she is showing its teeth angry similar to the Barbed Darts Monkey Sub and the Tribal Turtle (Standard Only, not Pro).
  • Overclock Engineers' sentries in Bloons Monkey City Flash are called SentrySprockets, and do not receive Monkey Knowledge buffs the same way the normal sentries do (except for camo detection).
  • This upgrade dramatically increases the attack speed of Super Sentries if its Tier 4 Speciality Building is active
  • In BTD6, a 3-0-0 Sprockets costs exactly $2020 on Hard Difficulty.

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