Motorcycle racer Guy Martin's two-wheeled world land speed record attempt got off to a disastrous start when the bike tipped on to its side as it was being towed to begin its first run.
Martin, 34, from Grimsby, had been waiting for the right conditions to undertake the attempt at the Bonneville Salt Flats, in Utah, USA, after the event was postponed on Thursday due to safety concerns.
But witnesses said the Triumph Infor Rocket Streamliner toppled over as it was being towed up the 11-mile course by a pick-up truck, leaving a noticeable scratch along its side.
Martin could be seen standing next to the bike wearing his helmet and leathers before walking back towards the start of the track.
A Triumph spokesman said Martin did not suffer any injuries in the incident and was "fine".
He said: "As he was being towed up behind the tow vehicle, they've gone over some rough ground, which has caused the bike to topple over.
"There's no major damage to the bike which is being brought back to the start.
"Guy is fine."
One witness said Martin was still keen to undertake the world record attempt.
On Thursday, all runs were postponed due to the course being "too wet to safely undertake any runs" but the team were hopeful the bike would be taken out on to the course on Friday.
Engineers had been working on the 400mph motorcycle during the day to prepare the machine for the attempt.
Earlier, Martin sat in the bike as members of the team made adjustments and watched as the turbo twin engines were tested.
The Isle of Man TT star was due to try to reach a speed of 300mph on his first run before being allowed to attempt to break the world record - which currently stands at 376.36mph.
During practice sessions over the summer, the bike became the fastest to be built by Triumph as the TT star achieved a speed of 274.2mph.
It features a carbon Kevlar monocoque construction - in which the chassis is integral with the body - with two turbo-charged Triumph Rocket III engines producing a combined 1,000 brake horsepower (bhp) at 9,000 revs per minute (rpm).
The bike is 25.5ft long, 2ft wide and 3ft tall and is powered by methanol fuel.
Martin said: "The Triumph engineers have built an amazing machine, giving us the very best chance to beat the two-wheeled land speed record."
Martin has set speed records in a variety of human and engine-powered vehicles, including world records for fastest speed on a gravity-powered snow sled, fastest speed in a soap box and highest speed on a wall of death, which he set earlier this year.
The current motorcycle land speed world record was set by Rocky Robinson in 2010, riding the Top Oil-Ack Attack Streamliner at 376.36mph.