Those Ezy wheels were not really suitable for the Flamingo, as they were too small. Although they were smooth rolling, the tiny size made it vulnerable to getting stuck in crevices and gaps in the ground. Thus, I kept on searching for suitable roller wheels.
I finally found some suitable roller skate wheels in a roller skate shop at Novena! Thanks to 明天 who alerted me to the wheels. A set of 4 wheels was obtained, and they are of similar size to the original roller wheels on the Flamingo.
Originally meant for roller skates!
Good quality wheels, at an affordable $10 per set
However, as with most modifications, it is not as easy as just swapping the wheels. The original roller wheels uses M6 bolts as the axle for the wheels, and this bolt size has to be maintained as there are corresponding M6 screw threads on the bike rear rack. These roller skate wheels have a larger hole in the center, which is about M8 in size. If I had used just M6 bolts to install them, there would be a lot of play between the wheels and the axle, which will quickly destroy the wheels.
Thus, I had to find suitable shims to enlarge the axle, at the portion where the wheel bearing rests on the axle. Only then could the wheels be installed properly.
New roller wheels for the Flamingo
These wheels are quite good, as they are nice and round, unlike the original ones which had bumps and dents, that made it difficult to roll the bike. The bearings are also smoother.
Finally, I have found the ideal roller wheels for the bike! These wheels roll well, are of a good size for rolling over uneven ground, and are round enough to roll smoothly and easily.