sandblast and powder coat or you can use a wire wheel on a drill
Replacement forks for a Harley can be purchased from motorcycle stores, or for more specialised forks, one may wish to look on eBay or a similar site.
It's suspension in the forks and or rear of the bike.
Remove bolts at top of suspension forks. Raise front wheel off ground. Pour oil into top of front forks. Leave 100 mm or 10 cm measured from top of forks.
"should" doesn't really fit. All pics Google can find show them having suspension forks, but if the rider wants a suspension fork can be replaced with a rigid fork of the correct length.
paioli front forks and marzochi rear monoshock
A hardtail is basically a bike that hasn't got a rear suspension. It's usually used for Mountainbikes. MTBs are available in three "flavors":Rigids (stiff fork and stiff frames)hardtails, HT (suspension forks and stiff frames)Full-Suspension, FS (suspension forks and suspension frames)Other bikes as a rule don't have suspension components, so it's pretty much only for MTBs that you need to keep track of the different styles.
A normal motorcycle has springs built into the front suspension. You may not see them because they are inside the forks/shocks.
Suspension frame /forks, materials that are lighter/stiffer. Designs that are more aerodynamic.
Not sure how far they date back but I have a 2005 Z Force that is blue in color with grey forks. Really great bikes and built very well.
No, forks are typically made of stainless steel which is not magnetic. Magnets will not attract or stick to forks.
The bike that you should buy for your nine year old son is that with a 20-inch wheel with suspension forks and adequate front suspension.
I would talk to a suspension shop about what weight oil to use for your bikes forks and your weight and riding ability. It sounds like it might be time to rebuild your forks, possibly new damper rods and springs.