Roger and Bradley Stockton died last Friday when they crashed at the very beginning of their side-car class competition on the British Isles.
"The Isle of Man competition deplores the grief of Rogers and Bradley's family and friends," the organizers wrote in a statement.
The motorcycle festival is the most classic of all motorcycle competitions - not least because it is dangerous to drive.
Since its premiere in 1907, 265 people have died.
"Like Mount Everest"
The different classes are decided over two weeks on a 60-kilometer course, mostly on public roads without safety barriers and with dense crowds close by.
On some routes the speed is up to 200 kilometers / hour.
The drivers are mainly amateurs and come from all over the world to drive the classic track.
Despite the lack of security, the interest is great and the competition may continue to be arranged.
- I usually compare with Mount Everest, says motorcycle journalist Adam "Chad" Child to the newspaper Daily Star and continues:
- 20-30 people die every year when they try to climb Mount Everest.
But there is a steady stream of people trying to do it every year anyway - because it's such a challenge.
So I think it's with the Isle of Man race as well.
Critical condition
This year's competition is the first to be run in three years due to the pandemic and has been extra accident-prone.
As many as five competitors have died.
The sidecar driver Cesar Chanal died last Saturday.
His passenger Olivier Lavorel was taken to hospital where his condition is still described as critical.
Mc drivers Mark Purslow and Davy Morgan died in two separate accidents just over a week ago.
Friday would have been the last day of competition on the Isle of Man, but due to the latest fatal accident, the finish was postponed until Saturday.