The retractable tube is stored inside the body of the pump when not in use, and it can attach to either a Schrader or a Presta valve, the two types of valves you’ll see. Some pumps can accommodate only one type, making them less universal. Toggling between the two is simple, which can’t be said of other models with itty parts that require nerves of steel to handle on a good day, let alone while wearing gloves, crouching in the wind, oblivious to the sewer grate a few feet away.

It’s both surprising, and not, if you think about it. The way I’ve usually seen it happen is first the rear tire goes flat, then the front one. My theory is that both tires went through the same pile of glass/thorns/metal bits and they both picked up junk. the reason for the flat occurring on the back first is because there’s more weight on that tire, so the offending article works its way through the tread more quickly.
For the budding mechanic:  A good pocket sized repair guide.   One good option is the “Pocket Guide to Emergency Bicycle Repair”  by Ron Cordes and Eric Grove.   It’s only 3.5×4.5 inches and a half inch thick.   I don’t carry this myself, but for someone who’s new to this whole bike repair business, it’s really helpful to have. A future blog post will cover this book in detail.
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 Administration & Event Services office is critical to every thing that happens at the heart of the UCF campus. They are your first stop when planning anything that happens at the Student Union. So whether it's providing logistics for your upcoming event, making room reservations or offering you guidance on proper procedure, the Student Union staff is here to help.
If you own a bike, you need a flat-fixing kit. It’s really that simple. Sure, maybe you’ll get lucky and get a flat close to a shop, or the buses will be running on time for once, but even with all that going for you, getting stranded across town will cost you time, money, and precious sanity. You can put together a great kit in less time than it takes to read this guide.
The thumb test is the fine art of pressing on the tube with your thumb to see if it’s inflated. During testing, I took a pressure reading out of curiosity, and to the touch, road tires feel fully inflated around 30 psi. How pathetically sad—30 psi!—when you’re probably trying to reach at least 60 psi on a mountain bike, 70 or more on a hybrid, and it only goes up from there.
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.