Saturday’s Superbike race saw Padgetts Honda rider Davey Todd forced to retire when his Dunlop rear tyre delaminated at the Sulby section of track.
This came on the cut slick Dunlop rear the tyre company had replaced its slick range with, after a number of high-profile failures at the North West 200 in May.
Harrison, who was almost 40s off race-winner Peter Hickman – also on Dunlops – in Saturday’s Superbike race, says he has struggled all week to adapt to the rubber having switched from Metzelers this year.
For Monday’s first Supersport race, Harrison had secretly switched to Metzeler tyres and was just five seconds from the win having not used that manufacturer since 2019.
Explaining his switch, Harrison says he had an issue with his Dunlop tyre “the other day” and was scared about riding on them again.
Autosport asked both his DAO Racing team and Dunlop for clarification, with his team saying it was a rear tyre hugger issue while Dunlop said there was no tyre failure.
“It wasn’t that bad,” Harrison said of his switch to Metzelers. “I set a sector record, it’s not all bad. The first time I’d used a Metzeler in three years, and I set down Bray Hill here because my [Dunlop] tyre fell to bits the other day and ripped my hugger off.
“And they [Dunlop] said to me you need to run 1.5 bar minimum, because that’s the problem.
“And I said I was already doing that, I had the highest pressure they recommended and it still fell to pieces.
“I’m just concerned over my own safety and everyone else’s, to be honest.
“So, I said I didn’t want to ride, I want to go home, I’m done. It’s concerning, it’s genuinely concerning. It’s dangerous enough without tyres blowing up.”
Harrison added that it “wasn’t my idea” to switch to the Dunlops for 2022 and has always been happier on Metzelers.
Hickman, who was third on his Dunlop-shod Triumph in the Supersport race, told Autosport that he expected a few more riders to make the switch after Todd’s problem but is not worried himself.
“I guess I was expecting a few people to change,” he said when asked about Harrison’s switch of tyre make.
“I haven’t spoken to anyone about anything, to be honest. Yeah, it is what it is.
“I’ve let the team sort out what they needed to sort out, but from my side I’m pretty happy with what we’re doing and how we’re doing it.
“There’s differences in how you set your bike up, in how your prepare the tyre for the race.
“There are so many variables, there’s so many variables that people don’t understand that can lead to what is happening.
“I’m not saying that we’ve got it perfect, and I’m not saying we’re not going to have a problem because we might.
“But as it stands at the minute, everything I’ve done so far is spot on.”
Asked if there had been any word on possible changes to the tyres over safety going forward, Hickman added: “If we’re forced to change, it won’t be from my side.”
