A man will set off from a primary school in south-west London to France on Friday - on a penny farthing.
The penny farthing can pose problems at traffic lights
Paul Graham, who navigates London traffic on his antique bicycle, is making the trip to mark 100 years of St Osmund's School in Barnes.
He will make a round trip from Barnes back to Salisbury Cathedral, where St Osmund is buried, via Normandy.
"Once you've learnt to get on and off it is much more comfortable, I think, than a modern-day bicycle," he said.
"But of course getting on and off at traffic lights is quite difficult."
Mr Graham, whose children go to St Osmund's, says he has clocked up nearly 6,000km on his penny farthing over the course of seven trips.
"It certainly attracts a lot of attention when I'm riding around," he told BBC London.
He hopes to raise several thousand pounds for the school on his latest trip, which should end next week.