Unlike floor pumps, most hand pumps do not have pressure gauges. To get readings during my original round of testing for this guide, I built a special rig involving simple hardware-store parts. But the experts I spoke to seem divided on the usefulness of gauges. Half thought they were unnecessary, added bulk, and drove up cost. Why do you need a gauge if you know 100 pumps inflates your tire? But the other half liked them, because the “thumb test” is notoriously inaccurate.
First, I researched. I looked at Amazon’s top-rated products and their user reviews. Then I consulted Bicycling magazine, Gear Junkie, Bike Radar, Outside, and the occasional bit by Lennard Zinn via Velonews. I also found some worthwhile discussions at Bike Forums. Then I spoke with four experts, Ramona Marks, Scott Karoly, Cari Z, and Alison Tetrick, riders from all across the spectrum, who tour, repair, and race.
Modern bottom brackets use a sealed bearing type construction that keeps water and debris locked out, so they seldom go wrong. Maintenance is impossible so they need replacing when they do wear out. Older style cup bottom brackets need to be re-greased every now and again, and occasionally will need to have their bearings replaced. There are a lot more teeth on the chainring cogs than those on the rear cassette, so need changing less regularly. Cranks usually a solid one piece construction so there is not much to go wrong.