And even as he flew through the air, it never occurred to him that he might be injured as seriously as his dad.
Hamish was lucky to escape with only a broken collarbone and a dislocated shoulder - and there is no talk in the Lee household of banning mountainbiking.
Jenny Lee, Hamish's mum, said some people had jokingly suggested on Facebook that the family might want to have a rest from mountainbiking - but that wouldn't happen.
Hamish plans to be back on two wheels in next to no time, and even thinks his dad might one day cycle again.
"If he gets out of his wheelchair, of course he'll mountainbike again," said Hamish.
His dad, though, was not so confident of walking or riding again.
"If I was to walk again it would be wonderful, and only by the grace of God," he said yesterday.
After Hamish's accident, he asked his friend to text his mother Jenny to tell her he thought he had broken his arm and to come and pick them up.
He was taken to Lakes Primecare and has to wear a sling for six weeks. He expects to be out and about again soon.
Timothy Lee, meanwhile, says he has been getting "pretty frustrated" because at this time of the year he would normally be quite active.
He has enjoyed being at home and has achieved one of his short-term recovery goals - being able to flick the pages of his Bible. The achievement was a big one for the tetraplegic, and one he managed to do for the first time a couple of weeks ago.
He has visited several of the city's churches in recent weeks, sharing his story.
And he is looking forward to heading back to work next month at Rotorua Baptist Church where the wheelchair-bound minister will job-share with an associate pastor, Alby Mascheretti.
