Ethan Hayter rode well in the UCI Road World Championships time trial, but his hopes of a medal and the rainbow jersey were ended by a mechanical failure.

Hayter was fastest through the first intermediate checkpoint when his chain came off at the end of the first lap of the Wollongong circuit.

Hayter had traveled 15.7 km on the coastal road and was about to shift up to the big ring with 18.5 km left in Sunday's time trial.

The chain slipped and Hayter, unable to put it back on, had to stop to change bikes.

He got back on the bike, regained his focus admirably, and took fourth place, but was left to wonder what had happened.

"I'm a little disappointed. But a little disappointed."

Hayter attributed the set-up to a mismatch between his new Pinarello time trial bike and drivetrain components.

"When I was changing the chainrings ...... I got this new bike ...... Shimano doesn't make a chainring shifter for the new gears. [When I tried to change the chainring, the shifter didn't shift right, so I pushed it again and it fell off.

"So I had to replace the bike. From that point on, I think I was able to limit my losses quite a bit."

Hayter was using a no-brand 60t chainring instead of a Shimano 58t chainring. According to Cycling Tips (opens in new tab), he also used a Shimano single-button shifter and semi-automatic synchro shifter.

This chainring combination probably affected the crispness of his gear changes and sparked the chain dropout. Semi-automatic synchro shifting, on the other hand, meant that instead of giving the front derailleur a direct manual shift command, it would automatically shift based on a preset setting determined by the overall gear ratio. As a result, Hayter could not manually solve the problem and had to switch bikes.

The next problem was that Hayter's spare bike did not match the original bike.

"The brakes and handlebars are different, so the bike handles a little differently, but I think it worked in this situation," he added.

Indeed, Hayter was faster than eventual winner Tobias Foss at the first checkpoint, but a strong second lap saw him finish in fourth place, 40 seconds behind.

It is difficult to calculate exactly how much time was lost in the bike change, but it will not put Hayter's mind at rest.

"I have no idea," he said. But I might have tried; 40 seconds is pretty big to win, but it might have been close."

"There was no pressure. Except for my teammate Luke Plapp, no one really thought I was a contender. But I had a chance. Some of the guys were tired. Foss' win was no surprise to me, but maybe to the media. Fortunately there is a World Championships every year."

In any case, Hayter's performance will give him the confidence to lead Great Britain in next Sunday's road race.

"I was really disappointed to leave the Vuelta. I didn't show myself and for a week I sat on the couch and didn't talk to anyone. But I've changed my mind again and come back here fresh."

"Hopefully today will be good training for the road race next week.