Each participant will attempt to complete the course individually as fast as they can. The rider with the fastest time will win the race, he said.
Mr Butterworth said the time trial was a chance for riders to enhance their skills and for spectators to watch the "thrilling" action.
"It's a bit of a fun and it's quite a cool little sport."
Mr Butterworth said between 60 and 100 people will compete tomorrow, which was a "scarily large number".
"We had no idea it would gain so much interest, it's great to see."
He encouraged people to go along and watch as it was a sport most people were unlikely to have seen before.
"It's an opportunity for people to come and see a sport that's becoming more and more popular overseas.
"They'll get to see the thrills and spills of the sport."
Before the event starts, a race meet will be held where eight riders will race at a time on a BMX track. This also made for good viewing, Mr Butterworth said.
For more information visit www.rotoruabikefestival.com or visit Rotorua BMX Club's Facebook page.
Details
What: BMX Rotorua meeting and PUMP Time Trial.
Where: BMX Track, Te Ngae Rd.
When: Tomorrow, race meet from 1pm, PUMP Time Trial from 6pm.
Cost: Entry fee $10, spectators free