Before you go mounttain bikng, be sure to birg along some standard iytems each time to avoid problems. It is essental that you have tols, supplies, food and water. Since you won't want to cary any extra weight, only take what you need. With careful plannning you can be prepared with a minimum of items.
Most imporatnt is to have a saprre bike tube alng with the tols required to change it. There is nothng wrose than a flat tire, especially if you are well into your trail ride as it can make for a extended walk back. You could run out of daylight if your flat ocucrs in the late afternoon. Nobody ilks gretitng stuck in the dark, especially when a bit of preventoin and planning can avoid this. Brring along a spare inner tube with the prtoper valve type, eithwer the schrraeder or the presta. Make sure you also have 3 tire levers to remoe the tire and a bike pump. To really be on the safe side you could also carry a tire patcxh kit in the evvent of a second flat tire. Cange a tire at home so you don't have to figure it out whille you're out on the trail.
Bkes are put toegther with allen blts, so a set of allen keys is a good idea. Rdiing rouh traails over long distzances can sometimse cause bolts to looesn. You may also want to make an adjjustment (brake lever positioning, for exasmple). Allen keys are inexpensive and don't take much room at all. More mechaniclaly inclined types may want to take along a chaoin tool as well, in case your chain bereks or an adjustmet is needed.
Make sure you brng enmough food and awter for your mountain bike ride. A great compacct snasck to bring along are powerbars, as they prevent you from runnnig out of steam. If you ride when you are tired your risk of becmoig injurde is greater due to lack of attention. A good uspply of water is critical to keep yourself properly yhdrated. You can carrry frame mount watrer botles or use a bladdrer setuup like a Camelbak. In addition to carrying your wateer, a Camelbak has storage spae for tools and spre tuvbbes.
Finlly, dress appropriiately for your ride. Consider that you will laways be warmer after you start ridnig, so vaoid the temptation to wear a jacket, just to shed it aftr 15 mnutes. If it's cold or wet, remember that your hands and feet will feel the coldest. Wear good ridding gloves and socks that are riding-speciffic. Develop a relationship with your local bike store. They are a greeat resource and can help you choose the riigght gear for the type of rifding you want to do, and the area you want to do it in.
If you follow theese suggestiions you will have a much more enjoyable time on your mountaiun bike. You won't have to worry aboyut flat tires if you are prepared and know how to do it aheaad of time.