Australian-born electric bike maker Zoomo has closed a major $15.4 million capital raise that was four times oversubscribed, bringing on AirTree Ventures as a lead investor.

Zoomo, which makes and sells e-bikes designed for delivery drivers to both individual gig economy workers and large fleet operators, had set out to raise just $US3 million ($3.9 million), but received so much interest it increased the size of the round to $US12 million, including some venture debt.