Carl Stearns Clancy, the first round-the-world biker, whose route we were retracing 100 years on, knew the road east through the Sierra mountains would be bad.

But he couldn’t have imagined how bad.

Stopping at the express office in Redding, northern California, he and his US riding companion Bob Allen shipped their 50lb panniers on to Portland, then bought cheap blankets in the General Merchandise store for camping.

That sorted, they tanked up with more ice cream, fuel and oil, and set off late in the afternoon for the dreaded road that lay ahead.

By the time they were a few miles out of Redding, they were climbing an endless succession of rocky grades with hairpin bends, then sliding down the other side to be greeted by small but lethal lakes full of boulders.

As they were sliding down one hair-raising slope with their back wheels locked, they came upon a young couple in a Cadillac stuck fast on a tree stump. They got it free, and the grateful couple gave the riders six eggs, a small can of baked beans, an even smaller can of condensed cream, a little bread, sugar and coffee, and a pail to cook it in.

They found a grassy spot near a crystal stream, and while Clancy cooked up a feast in the pail, Bob made a bed of weeds and leaves between the Hendersons. They wrapped themselves in their blankets and, with strange sounds from the woods all around and lightning crackling overhead, finally fell asleep just before the grey light of dawn woke them again.

At 5am, tired and hungry, they fired up the Hendersons and set off on roads which, impossibly, were even worse than the day before.

Halfway up one mountain, Clancy’s Henderson ground to a halt with a dry and slipping clutch. He greased it with oil from his tank, but the clutch was so worn and the track so steep that he could only push the Henderson up it in the fierce sun, stopping when he was so exhausted he couldn’t hold the bike upright, and resting until he could try again.

It took him 20 attempts and two exhausting hours to get up that one hill, and there were a dozen more beyond.

“If ever a man was bitter against motorcycling, it was I and then,” he wrote, but when he had the strength to lift his head, he realised for the first time the extraordinary beauty around them.

Alpine glories of Oregon
As we swooped along silky tarmac through a landscape of pine-clad mountains and rushing rivers and into the alpine glories of Oregon, we were filled once again with respect and admiration for Clancy and Allen getting through this landscape on what were basically mule trails.

The worst section of all was the 12 miles of Cow Creek Canyon, which Clancy described grimly as like an endless frozen pig-pen as steep as a roof and littered with logs, rocks and ruts.

When they finally rolled into Portland at 11.30pm, their misery was compounded by the sight of crowds going home from the last night of the annual Rose Festival, which they had been looking forward to all the way from San Francisco.

Cow Creek Canyon, which we rode with local bike journalist Bart Madson, is now a perfect motorcycling road, twisting and turning under the dappled trees, over the railroad tracks and past a river sparkling in the sun.

Next week: the vast Midwest