Waikato police are investigating a motorbike's mechanics and just what effect clothing found wrapped up in its rear tyre had on a serious crash near Rangiriri.
The crash, yesterday morning, marks a devastating run of motorcycle crashes in the district over the past week.
In the latest crash, two riders were airlifted to Waikato Hospital by the Westpac Waikato Air Ambulance after their bike smashed into a roadside barrier on State Highway One near Rangiriri about 9am.
Motorists travelling south were diverted from the scene, causing major traffic delays for several hours.
Waikato Hospital spokeswoman Mary Anne Gill said the riders, a man and a woman, were in a stable condition and were being assessed in the emergency department.
It was likely they would be admitted to a ward.
The crash marked a busy weekend for hospital staff, with five people receiving trauma injuries in separate road crashes across the Waikato on Friday and Saturday, including a motorcycle accident on Saturday.
Sergeant Neil Mouncher, of Ngaruawahia police, said the Waikato serious crash unit was investigating the cause of yesterday's bike crash north of the Rangiriri Tavern.
Officers would take the bike to Hamilton for testing.
Waikato Times' photographs of the bike taken at the scene show what appears to be black clothing caught up in the back wheel.
"There were no witnesses to the crash and when I arrived the two people who were there weren't very talkative," Mr Mouncher said.
"There were reasonable skid marks on the road but we still have to work out what the story was."
No other vehicles were believed to be involved in the crash, Mr Mouncher said, adding it was important motorcyclists rode to the conditions "and their experience".
Six motorcyclists have died on Waikato roads this year.
All six riders were male, and the majority of accidents occurred on weekends.
Waikato road policing manager inspector Freda Grace last week described the recent spate of crashes as avoidable.
- Waikato Times
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