The exact items that you should bring with you on any given ride will vary depending on the type of ride (how long, how fast, how far)… but below are some key items that you should have with you on just about every ride.
1. At least one replacement tube (if you are not riding on tubular or tubeless wheels). Make sure you have the right size tube for your wheel / tire set up. There are MANY different sizes. Most road bikes roll on 700×23 tires @ 100 to 145 psi… so you’ll need a tube that is rated for that size tire (if that’s the size you have on your bike). You also need to make sure that the VALVE stem is the correct type and length for your rims. The deeper the rims are, the longer the stem needs to be. Most road bikes use presta valves… many other types of bikes use schrader valves. I’ve had two flats on the same ride before–so I always carry 2 tubes and two cO2 inflators.
2. Tire levers. You don’t HAVE to have them to change a flat all the time… but they sure make it easier… especially for a beginner. For most tires all you need is one… but they have been known to break… so two or three is better.
3. A pump… or CO2 inflator kit. (You should practice with either option you choose at least once before you have to use it out on the road. You don’t want to be standing there reading instructions while the rest of the riders in your group stand around watching you try to figure it out.) Even if you don’t know how to use it, someone riding with you probably will. Having a spare is a must. You may get more than one flat–or if you have fatter tubes / tires–it may take more than one to do the trick.
4. A good multi-tool. (I prefer one with a chain tool… since chains have certainly been known to snap out on the road. If you have a chain tool in your kit–and know how to use it–you won’t have to walk your bike for miles in uncomfortable cycling shoes–or barefoot–or sit for an hour or two waiting for someone to come pick you up.) As with the CO2 systems, you should have a good basic understanding of what every tool does before you have to use it out on the road. Check out manufacturers website or watch YouTube videos. (I personally prefer the Crank Brothers M-series or the Parks IB3… both available on Amazon.) Even if you’ve been professionally fitted to your bike, there will probably be times when you wish the seat was higher… or lower… or closer to the bars… or farther back… and without a basic set of tools you’ll be stuck in that position for the entire ride. Also, sometimes the cleats on your shoes come loose and you need the right hex bit to tighten those back up.
You should also have a quick link or two that works with your particular type of chain. (9 spd / 10 spd / 11 spd, Shimano, KMC, Campy, etc) I have had chains snap in two on more than one ride… and with a quick link in your bag you’ll be back in motion in a matter of minutes. (But if you have a chain break tool on your multi-tool, you can usually fix the chain as well; just takes quite a bit longer.) Quick links are very small and very inexpensive… so, no excuse not to carry them!
5. Cash. A credit / debit card. A drivers license or other i.d. (Longer group rides usually have stops for hydration, snackies, and bathroom. You may need to buy drinks, food, gum, etc. Also, if you do have a major mechanical that you can’t fix on the road–you may need to take a bus / cab / uber back to wherever you started from. And… worst case scenario… if you are out riding alone and get hit by a car or solo crash, if you have no ID or insurance card on you, it will certainly make it more difficult for the EMTs or law enforcement to do their jobs and get you the help you need and / or notify your next of kin. (A Road ID is certainly not a bad idea either. I always ride / run w/ one.)
6. Sunblock. Lip balm. Sunglasses. Chewing gum. (These are a few of my favorite things!) Pretty self explanatory. (I like to chew gum when I ride (or hike or run) to keep my throat from drying out; I drink less water.) Sometimes it is dark (early morning) or cloudy when you start the ride but gets sunny and bright during the ride… so always smart to keep sunglasses with you… unless you are riding in the evening or at night… in which case you will want to ride with clear or yellow lenses (to keep your eyes from drying out and to prevent debris from the riders in front of you from flying up and hitting you in the eye).
7. Cell phone. (You may want to keep that in a plastic sandwich bag if you ride with it in your jersey pocket… will keep it from getting damaged by sweat or rain.) You may not THINK you’ll need your phone… but when you get that SECOND flat–20 miles from home–you’ll be glad you have it on you. I use a flip not a smart so I just tuck mine away in my tail bag w/ my tubes and tires.
8. House keys (if you rode your bike to the ride) ; car keys (if you drove your car to the ride). (I usually have a spare set that take with me / keep in my kit so I don’t run the risk of losing or damaging my main set on a ride.) Many tail bags have a clip inside to secure your keys so they don’t fall out. A guy lost his car key on a ride I was on not long ago and had to call his wife to come down and get him from the Woodlands… which is about an hour drive each way. Needless to say, she was NOT happy. He had left his bag partially unzipped and the key had rattled out somewhere along the 70 mile route… never to be found again. It was a newfangled / coded key that cost about $150 to replace at the dealership. 🙁 Not good. (One down-side to keeping your keys in your jersey pocket when you ride is that the keys can–over time–cut a hole in your pocket. Also, if you have an expensive new-fangled key, getting soaked in sweat probably isn’t ideal.
9. Fuel. And by this I mean things like PowerBars and M&M’s and any other good snackie of your choice. The longer the ride the more–and the more often you need to eat. ALL of the fast riders I know eat about every 30 minutes while they are riding. This keeps them from fading at the end of the ride due to lack of energy / lack of fuel in the tank. And you don’t have to eat super healthy just because you are exercising. Some of the fastest riders I know eat candy bars and drink sodas or energy drinks at the stops… because those simple, refined sugars give you instant energy to burn. I personally like Craisins on my rides; they come in a re-sealable pouch and fit nicely in my jersey pocket… and come in a variety of flavors.
10. Camera. Some of the best rides I’ve been on were in amazing, beautiful places… mountains… deserts… valleys… rivers… lakes… oceans… farmland. Whether alone or in a group it is great to have a small point and shoot handy to capture the moments and share them later… or to snap a pick of the license plate of the guy who keeps flipping you off and trying to run you off the road. 🙂
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All if not most of the above should fit in a basic tail bag and your jersey pockets. Also, if you are riding with a friend or a group, someone else will almost certainly have one or more of these items that you could borrow in a pinch. So don’t be afraid to ask another rider if you really really need something you don’t have. Just always make sure you replace it or reimburse them for it if it is a consumable (tube, CO2 cartridge, etc).
One of the great things about cycling jerseys are the three big pockets in the back. If anything you need to bring won’t fit in your bag–just stick it in one of your back pockets!
I used to like to bring a small ipod (shuffle / nano) when I ride… though I’ll only use one ear bud if I’m riding in a group or a dense urban area where I need to hear audible cues, warnings from other riders, emergency vehicles, etc. But if traffic is light or I’m out on the open road–riding alone, I’ll often use both ear pieces. (Lately I’ve been using bluetooth headhones tethered to my phone when I ride. That way I can listed to music if I want and answer incoming phone calls if I want… without having to expose my phone to the weather / sweat / dops / etc.