A constant stream of people - young and young at heart - took Spencer's creations for a spin around a training course at the base of 17th Ave while the main pedal party was taking part on one of the community cycleways in the valley.
Spencer's bikes included a children's Penny Farthing, a bike with four wheels, a bike with an offset front wheel and another with a passenger side seat - all made by the hands of the octogenarian.
"Some say they are funky bikes, others say they are crazy bikes," Spencer said.
"The thing is having the kids riding them and having fun."
Spencer said there were plenty of people who knew him as the "crazy bike guy", not that he minded.
"It's not all about me though. It's the kids having fun."
The pedal party was supported by the Tauranga City Council and Sport Bay of Plenty, which has offered a range of Bike Month activities to promote cycling and its benefits.
The council's Travel Safe team leader Karen Smith said the day was about bringing people together to enjoy the fun of cycling, on whatever level.
"To have days like this is just wonderful, for it to be free for the community and we've got families of all ages using the cycleway, a little boy who learned to ride for the first time and others just having fun. It's about people connecting with each other in a fun, low-key environment."
Smith said Spencer was an integral part of Tauranga's cycling community, regularly helping fix children's bikes and making them safe.
"He's an absolute community gem," Smith said.