Father-of-one Andrew Jenkins, 53, will pedal to Maggie Cancer Care centres in Swansea, London, Cambridge, Inverness, Glasgow and the Wirral.
He wants to raise funds for the centre after being diagnosed with angiosarcoma, a cancer of the inner lining of blood vessels.
Mr Jenkins bought the Dutch-made velomobile, revamping it for the ride.
"You are basically lying flat out with your legs forward. You don't want to get out."
A Swansea University engineer with terminal cancer is set to ride a baked bean-shaped bike around the UK.