If you are anything like myself or the folks with whom I turn the pedals, you probably like to turn the pedals hard and put your two-wheeled love machine through the paces. When said activities are taking place you rarely have time to be thinking about whether you torqued your XTR cranks to the specified 13 NM or if it was done in the alternating fashion prescribed by the Japanese God of Cycling, Shimano. Hopefully, you or your wrench of choice has done said things and you can ride into the sunset without worries.
But as I started this here post, the world is imperfect and shit happens. Anyone who rides has found themselves stranded on the side of the road with a broken bike in one hand and the look of defeat in the other. At this point you hopefully aren't praying to the Japanese God of Cycling that you remembered to restock your saddle bag or that your multi-tool is, in reality, safely tucked in your Deuter hydration pack. If any of those thoughts are racing through your mind, you are not alone. Many a cyclist has been stranded on the side of the road hoping that the red neck that just about killed them five minutes earlier can forget the middle finger salute they received and give said cyclist a ride back to town.
Seeing that I tend to ride with people who are proficient in maintaining and repairing their own bicycles, I have found that there exist two main types of trail side repair
This style of trail side repairman is a Boy Scout. He (no gender specificity intended, we just don't have good pronoun in English that denotes both male and female) can usually be recognized by the size of pack that he has strapped to his back. It will be large. It will also be full. This type knows full well what compression straps are for, his pack has 'em and he intends to use them. Due to said pack and the load that it contains, this rider tends to be a "trail sweeper." He is one of the last to the top of the climb and since he just hauled 45 pounds of bike tools to the top, he is tired and will also be one of the last ones down.
Despite his speed, or thanks to it depending on how you look at things, this repair person is a good friend to have. Oh you broke a Crampandgoslow cable? No problem. Is that brake or shifter? He's got both even when he is on a dirt ride. Did you forget to tighten your cleat and it fell off? No problem. What variety is it? Speedplay Frog? Yup, got 'em.
He's also despisingly organized. If you ever need anything, you will get the opportunity to see the inside workings of his pack. Everything is in there and everything has a place. You can stand and give thanks to the Japanese God of Cycling that you have seen such an amazing display of OCD.
This rider believes that his bike is working and should continue to work until the end of the ride. The repair person, isn't really a repair person seeing that he doesn't carry anything to help himself out with on a ride. A tube? Maybe but that usually depends on the distance of the ride. And if he does have a tube it will probably be the wrong size. A pump? Probably not. I mean really, how often do you ride and there isn't someone around with an air compressing apparatus?
This last rider also usually tends to be a professional wrench that has been in the trenches for so long that what he does is work. This means that he is going to avoid doing it when he isn't at work. If you need some help on the side of a trail, he may give you some pointers and he will definitely grab a flat tire from you (after he has watched you struggle with it for ten minutes and he gets bored) and put your tube in it. He will bum 5mm wrenches from you, CO2 cartridges and has been known to run 26" tubes in a 29er just cuz that was what was available (Damn those different sized wheel bikes any way).
Of course, there are a range of folks in between and I offer you these two exhibits as examples only.
Now if you happen to be new to the lifestyle known as cycling or a member of Exhibit 2, here's some advice on things you should carry.
Item A, a tube. Regardless of what tire/tube/liner combination you run and despite what the guy who sold 'em to you told you, you are going to get a flat at some point in your career (of course, I use this word loosely). It is best to also ensure that said tube is the right size for your bike. Patch kits are a great thing to have as well, but do you really want to have to sit and patch a tube on the side of a busy road, in the rain just so you can get home? I didn't think so. Patch kits are back up for when you get more than one flat on a single ride.
Item 2, a multi-tool. At some point you are going to need an Allen wrench. I also strongly encourage a multi-tool that has a chain breaker on it. Of all the things that can happen to you while riding breaking a chain is probably the most crippling. If you don't have that chain breaker you will be limping back, but if it is in your pack you can take a link out and avoid certain gears to get you back to town.
And Item iii of our bare necessities list, is a pump. You can carry a tube all you want but it is pointless without some sort of air compressing apparatus. I don't care what your VOMax is, you cannot get proper air pressure by blowing into a Presta Valve.
There you have it. A perfect trail side repair