BRISTOL, Tenn. -- In the blink of an eye, Jimmie Johnson went from leading at Bristol Motor Speedway to multiple laps down due to a tire issue.
The six-time Sprint Cup Series champion led 44 laps early Sunday, but began slowing while running second to Matt Kenseth and pitted for an apparent flat right-front tire on the half-mile track. A caution for rain came out during the No. 48 team's subsequent pit cycle, and Johnson was left two laps down in 39th place when the event was halted under a red flag. Johnson ended the night two laps down, in 19th place.
Over the radio after the incident, crew chief Chad Knaus told Johnson that the tire "just came apart. It's not even flat. The tread came off of it. There's nothing wrong with it. The rest of the tire's great. But I'm sure that's something we did. I'm sure that's our fault."
The No. 48 team is no stranger to tire issues, most famously at Phoenix late in 2012 when a tire problem led to a crash which effectively ended Johnson's championship hopes. Johnson showed off the remains of the tread, which had been pulled into long strands, on Fox television during the rain delay.
"Something made it come apart in this really long 50-foot section," Johnson said. "I don't know if we clipped something on the track that wore the tread and it unwound, or if something else happened. ... Either way, we're down multiple laps."
A representative of Goodyear, which provides race tires for NASCAR's national circuits, pointed out that Knaus chose to take only left-side tires during the competition caution at lap 50, which was issued because rain earlier in the day had washed rubber off the track surface.
Goodyear termed it "literally a high-wear situation," which can cause the spiral-wound tread on the tire to become completely unwound like pulling a thread on a sweater.
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