Old kids bike upgrade questions
I found an old 24" Giant road bike (ISO 547) in nearly showroom shape for my 9 yo daughter ($40!). It has steel frame, steel wheels, and 6x2 shifting via stem mounted friction shifters. The derailleurs are just cheap shimano SIS.
She doesn't like the drop handlebars. I would like to replace em with a flat bar and use grip twist shifters so she doesn't have to lift a hand off to shift (she struggles with that). The only 6 speed shifters I can find are on ebay. (SRAM MRX, Sunrace M30). Will either of these work?
An "out there" thought is to buy new aluminum wheels, and upgrade the drivetrain to 7 speed. Google found one shop that custom builds 520 wheels, but not sure if the brakes will still work? Is there a source for narrow road 547 wheels that won't break the bank? 540 wheels? I've just never dealt with 24" wheels before.
Getting aluminum rims is a splendid idea. Steel rims stop very poorly when dry and almost not-at-all when wet. Your daughter deserves better.
Sheldon Brown lists both ISO 520 and 540 Aluminum rims. The radius difference between 540 and 547 would be 3.5 mm or about the same as between 27" and 700c so the brakes might make the adjustment.