I used a Metz AF 48 N into a 65cm Aurora Firefly. The flash and softbox are hip-high left, just outside the picture-frame and I triggered the flash with cheap Yongnuo trasmitters from Amazon.
The important part was not to overdo the light/flash power. I wanted the blue to shine without highlighting all black parts or the environment. In the end I powered the small flash down to 1/16 and dropped my T-Shirt above the upper part of the lightformer. That helped a lot in controlling the light, but i got about 50 mosquito bites within three minutes and ran around like a Gorilla, scratching my belly and chest for a few days.
Off topic: check this: https://www.youtube.com/watch?v=J9lqgesBfzM
27.5 has quit the stage except for a few downhill mullets (I am too much of a weakling for downhill)
PS: The Geometron is a great looking bike. The slack front and big gap between wheel and frame look awesome. It must be perfect on fast trails or enduro sections