After fixing up a few old bikes I don't replace things as much as I did. I keep wires, both inner and outer if nothing is visibly wrong and every thing works, I add a bit of teflon oil to the inners. I even keep tires more often than I used to, but I have to admit, I replace rough pattern tires with slick ones for easy rolling.
I have an old Raleigh that takes odd size tires. When it was new to me it took me a couple of weeks to find the right dimensions and I ended up test riding the bike with the old tires on short trips into town. The rear tire lasted about two weeks before I had a flat, but the front tire I had for nearly 4 months before anything happened. It was old Dunloop tires, crackes in the rubber, the inner weave was showing in places, they looked terrible. The tubes were just as old, several decades, they still lasted a long time. I can't recommend anyone going for tires as bad as this, but it became a sort of test for how long they would last. 5 and 10 year old tires can be fine, all depending on storage.
Inner tubes can stand up strangely well to age, patchings last and are dependable. Break rubber can go hard and loose their grip, if the are hardly worn and still grip well, there's no reason to replace them. Sand down the outer layer and they might be fine. Just be observant on how the behave in wet and dry conditions. Old doesn't mean it's bad quality, worn or deteriorated by age. High speeds and racers need optimal breaks, it all depens on the bike and situation. I just check that things are working and feel a bit bad if I replace perfectly good part, they will soon enough need replacement.
Last edited by Mickey2; 07-14-19 at 05:13 PM.