Professor Mark Rickenbach, a GP in Chandlers Ford, Hampshire, rode with Dr Frank to the Pyrenees.
The group rode 90 miles or more a day for 15 days, and climbed the equivalent of Mount Everest (29,029ft) and Mount McKinley, Alaska, (20,320ft) combined.
To date, they have raised £63,000 but aim to raise millions over the next few years.
To donate, visit www.justgiving.com/Tim-Frank