Robert Waterhouse, 57, will fly to America at the end of next month and cycle from historic Williamsburg in Virginia on the east coast to Vancouver in Canada on the west coast.
Mr Waterhouse, from Harrogate, is seeking sponsorship from individuals and businesses to help him raise at least £5,000 – one pound for every mile cycled – for Shelterbox, an international disaster relief charity.
He is funding the trip himself so every penny he raises in sponsorship and donations will go to the charity.
Mr Waterhouse said: “With reports of global disasters hitting our screens on an almost daily basis, I decided to do my bit to try and help the relief efforts.
“I’m in the fortunate position that I have the time to do something like this. If anyone would like to make a donation, no matter how small, it will be going to a very worthy cause.”
He will be tackling the gruelling ride as part of a 14-strong group of cyclists from across the world.
A keen long distance cyclist, Mr Waterhouse has previously cycled from Land’s End to John O’Groats but this will be his toughest challenge so far.
He faces a trip equivalent to cycling from Land’s End to John O’Groats five-and-a-half times, carrying everything he needs on his bike, including camping equipment.
The Shelterbox charity helps victims of natural disasters and conflicts by delivering boxes of essential items.
Each box supplies a family with a tent and lifesaving equipment, and the charity has already started to deliver shipments to Japan.
Mr Waterhouse will provide updates on his preparations and progress on the ride on a blog at http://transam2011.blogspot.com
Donations can be made at http://uk.virginmoneygiving.com/robwaterhouse