A wrench that fits the hub nuts: If your bike has quick release front and rear wheels, you don’t need this, but if you have an internal hub on the back, such as the NuVinci, a wrench that fits is a great idea. 99% of the time, this is a 15mm wrench, but you should check your bike. A 6 inch adjustable wrench can also work, but it will be heavier, and when using an adjustable wrench, you do need to take more care to not round over the nuts. A fixed wrench is the best choice. Some multi-tools have a 15 mm wrench built in, but again, if you have limited hand strength, something with more leverage is a great idea.
Create emergency patches on tires or tubes with this Bike Tire Repair Kit. Each pack comes with everything you need to fix a flat, including a spokes wrench. When you find a puncture or nail hole in your riding essential, grab an application from this bicycle repair kit to hold in enough air so you can continue on your way until a replacement tire can be located. It includes adhesives and patches of different sizes for your convenience. Made of steel, the bicycle tire repair kit is durable and long-lasting. Keep the set with you at all times while riding your bicycle so that you have it in the event of an emergency. The size of the kit makes it easy to carry in a backpack or zippered cargo bag. Cover different sizes and types of holes and tears that make riding difficult with this Bike Tire Repair Kit.
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.