I like to convert MTBs to more upright bikes as I find flat bars uncomfortable, much preferring bars with some backward sweep. The Giant is a 1990s “Boulder 550” model which I found dumped for the council waste pickup, minus the wheels, seat and post and brake pads. The micro-drive triple chainwheel was badly damaged and parts are not readily available now, so, as the Red Ricardo has some frame alignment issues, I dismantled it for the moment and used its nice “Tracer” brand chainset and its rear wheel on the Giant.
Both these frames are large, the Giant is a 61cm (24″). I can just touch the ground from the saddle with one foot. I fitted it with nice alloy V-brakes from an otherwise horrible Huffy suspension bike. All parts are ones I had on hand, the only costs were new pads, brake and gear cable inners and some purple touch up paint. Originally a 21 speed with grip shifters, I have converted it to 6-speed using an old click shifter and adjusting the derailleur stop screws and cable on the original Acera-X rear mech. It shifts fine and 6 gears are enough for me, keeping changing simple .
I enjoy playing around with such things, it’s amazing what is compatible between older low-tech bikes. The Giant is a work in progress, I like its tight turning circle and comfortable balloon type tyres and take it sometimes on my 20-30km neighbourhood morning rides, not expecting to win any style awards of course . It badly needs a new seat too.