A St John spokeswoman said the woman's condition was downgraded from critical to "serious but stable".
A KiwiBank employee, who wished not to be named, was walking to work when she heard a scream. "I turned around and saw the bike go under the truck and it was bouncing up and down under the truck.
"There was a lot of howling and screaming."
The woman ran straight to the scene and her colleagues brought a tarpaulin to cover the cyclist, who was pinned under the wheel.
"People were running up the road to help and were already on their cellphones calling and ambulance."
Other KiwiBank staff were angry to see a passing motorist taking photos of the crash from their car.
One staff member said: "That could be someone's mother, daughter or wife. How would they feel if the tables were turned?"
Across the road, Ross Jones at Milford Butcher said he too heard screaming.
"We heard a bloodcurdling scream. That was the only thing that alerted us to it.
"We rushed to the door but [the accident] had already happened."
He said there were not many accidents at the intersection.
Another witness, Chantel Allen, said she was driving through Milford at 9am when she saw the accident.
"Traffic was at a standstill so from my car I could see the entire scene," she said. "I saw police taking photos of her bike, I saw her arm even though they were holding up ambulance blankets and one of the ambulance officers was holding up an IV drip.
"She was still on the ground and there was a stretcher waiting for her but my guess is they were trying to stabilise her before taking her to hospital."
Linda Gore, the manager of Crafty Knitwits on Kitchener Rd, said she didn't see the crash but saw the bike "buckled" on the footpath afterwards.
"A customer sitting in the window heard the crash. The truck driver was sitting in the truck in shock. Someone had to help him out of it."
The area was mostly cleared as of 9.40am, but police were still at the scene.
A northern police spokesman said police were called to the incident at 8.30am. The serious crash unit attended the scene.