We focused on tools that would be useful to a commuter—someone trying to use a bike as a functional way to get around town, as opposed to riding recreationally (road biking and mountain biking). That said, it’s a wild and wooly bicycling world out there, and the streets are packed with so many different bikes, all shapes and sizes, new and old. Customizing your flat-fixing kit has advantages over buying a preassembled kit that always contains a tool (or two or three) that’s a piece of junk, or you don’t need. Or it’s missing something you do need. If you build your own kit, at least you know everything works. And you can add only what’s necessary for your specific bike without ending up with stuff you don’t need.
Any bike that gets ridden seriously as transportation or on long rides needs at least a basic tool/emergency kit, and the knowledge to use it, unless the rider is always in a position to call a friend with a car or a cab when their bike needs a quick fix on the road. If you never travel more than a few miles, this can be overkill, and calling a friend or a cab may be just the ticket, but if you want to be more self reliant, this is something you should seriously consider. This list may sound like an awful lot of stuff to carry, but really, it only weighs a few lbs and fits in a small, under-seat bag that comes off quickly so I don’t have to leave it with the bike if theft is a concern. If you always carry a regular rack top bag, you can also just put all this in a small nylon bag and throw it in there, but I prefer an under-seat bag.
I chose to test these four levers after eliminating everything out there that’s not appropriate for a roadside emergency kit. That includes metal levers. They’re durable, but according to touring cyclist Ramona Marks, “Metal tire levers are trouble. It’s possible to rip your tube even with the plastic ones if you’re not careful, so metal is out of the question, and you don’t want to put pressure against the wheel rim with a metal lever.”
On the other hand, an on-bike repair kit will be a much smarter selection of tools that you are most likely to need. You should figure out the type of screws that are fitted on your bike and the things that are most likely to go wrong on a ride. Address only these things so as not to burden yourself too much with unnecessary stuff. Moreover, there are bike repair kits used on long rides and those used on shorter rides. The longer the ride, the more tools, and spare parts you will have to bring unless you want to have a very long hike back home.
Riding the bus with three infants in a stroller is no easy task, especially when you realize you have a flat tire as soon as you step foot on the pavement of 2nd and University. Luckily, I found The Bicycle Repair Shop. Andy happily filled my tire with air, and when it was flat again an hour later, found a replacement tube in minutes. He changed the tire with the babies still in the stroller! This was such an amazing experience that totally made a fun day possible for us! Thank you, Andy!
The fabric attachment system is low-tech, but that seems to be helpful, as it can adapt to seat rails of different widths. One fancier option you might see on more expensive seat bags is a quick-release mount that you install under your saddle. But those have a fixed width, and therefore can fit under seats with only those exact specs. Brooks saddles, for example, are too wide for these mounts.
If you’re going to use the chain whip you just made, you’ll also need a way to get that cassette off. A lockring remover is a must-have; unless you use one of the shady removal methods I’ve seen on the internet—which I wouldn’t necessarily recommend unless you don’t care much about the condition of the wheel after you use them. I recommend Park Tool’s iterations here that cost about $6, but you’ll need to buy the specific one for your brand/type of cassette. (By the way, I’m assuming you already have an adjustable wrench laying around somewhere to use with this tool. If you don’t, well, you’ll need one of those too.)
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.