The best medicine is often preventive and the best way to avoid mechanicals on the trail is to ensure your mountain bike is in working order before you hit the singletrack. Despite our best efforts, stuff happens. You should be prepared to rise to the occasion and save your ride when it does. We are not going to give you half-baked advice, such as how to use a tree branch in place of a handlebar if your handlebar snaps, or suggest that you stuff your tire full of leaves if you get a flat. Instead, these are practical solutions to common mechanicals that you or your riding buddies are likely to encounter.
Know how to pump properly
There is a right and a wrong way to use a hand pump. The wrong way is to rest the wheel against your thigh and pump like crazy. Although it is effective, this puts undue stress on the valve stem, increasing the likelihood of damage. Try resting the wheel against the ground and propping up the pump with a log or rock, so the head of the pump is in-line with the valve. Now you’ve got a firm surface to push against and gravity working on your side. Even better, use a hand pump with an extendable hose to lessen stress on the valve stem.
Give sidewall tears the boot
Tubeless sealant does a good job of stopping small punctures from ruining your ride, but cuts larger than a quarter inch often require the use of a tube and a tire boot. You can not simply install a tube without bothering to cover a torn sidewall, or you may notice the tube starting to bulge through the tear, soon to be followed by a loud “bang!” and then a long hike out of the woods...
Keep your used energy gel and bar wrappers close at hand, not just because littering the trail makes you a jerk, but also because they come in handy in situations such as this. A wrapper makes a great tire boot in a pinch.
Carry the right multi-tool
A broken chain can be one of the most jarring mid-ride breakdowns. It happens under power, usually while you’re really cranking up hill or shifting, whenever you shouldn’t be. It does happen and you should always be prepared to fix it with the proper tools, while it’s not nearly as common as getting a flat. There are countless multi-tools on the market, unless you’re willing to carry a separate chain tool with you, don’t bother investing in one if it doesn’t have a built in chain tool. Make sure to pack a master-link as well.
Fix a cleat with your bike’s 'backup bolts'
Imagine this: you just finished a grueling hike-a-bike section, you go to clip in, but something feels sloppy. Then you realize you’re one cleat bolt short of a pair. Take it easy, your bike has 'backup bolts' you can use in just such a situation. In a pinch, a rotor bolt will work as a cleat bolt. Running five rotor bolts is safe enough to get you home, but it might not be the ideal. So I do not recommend this solution for weight savings, but it will get you home while allowing you to use both pedals.To reduce risk, take a rotor bolt from the rear wheel, and practice clipping in and out a few times before you start riding again to ensure there are no interference issues between the new bolt and the pedal.
Cleaning a mountain bike is actually not that hard although it sounds daunting. A mountain bike doesn't need to sparkle in the sunlight; it's just going to get dirty the next time the sun is out anyway. But a regular cleaning routine can prevent problems down the road. Besides, a clean bike will last longer and improve performance.
Prepare for a dirty job.
Cleaning your bike is a messy job! Don't even think about wearing your favorite shirt--or any shirt you don't want to be covered in grime. Putting on a shop apron and rubber gloves isn't a bad idea, either. If you thought you could do this inside four walls, you thought wrong. Unless you're in an area where black grease won't look out of place.
Collect cleaning supplies.
Before you get to scrubbing, make sure you have the appropriate supplies. Park Tool recommends the following materials:
Bicycle cleaning brush
Rags and sponges
Biodegradable dishwashing liquid
Because of warmer temperatures will clean the bike better, both buckets should be filled with hot water. Dishwashing liquid should be mixed into one of these buckets. As you clean your bike more often, you'll be able to decide which tools from the list above you can't live without.
Scrub, scrub and scrub
Clumps of mud, leaves, sand and other grime should be wiped clean from your bike after every ride because it can destroy drivetrains, brake pads and shift, and it's heavy. If you have one, place the bike in a repair stand and wipe the whole rig down with soapy water and apply degreaser to the drivetrain after obvious souvenirs from the trail are removed from your bike.
Removing the wheels will allow you to clean areas that are typically unseen. Brushes, rags, and sponges should be used to get rid of mud and other grit. Just remember to gently scrub your bike down. You don't want to damage your paint job!
Don't neglect your chain and rear cassette. You can either manually clean the chain by gently scrubbing with a brush (a toothbrush works well for this) and water right where it meets the rear cassette, or use an on-the-bike cleaning machine, which clips over the lower part of the chain and bathes the chain in a solvent. Backpedal the chain through a rag drenched in degreaser once it's scrubbed clean.
Wash all areas of the bike down with a biodegradable soapy water mix. Then rinse it down with a hose. Note: high-pressure water hoses are NOT safe to spray your bike with. Use a garden hose on a gentle setting and don't spray water into the bearings.
Lube & Grease
Once your bike is dry, your chain, cables, levers, shifters, derailleur pulleys, pivot points, and brake bosses need to be lubricated. So as not to invite more dirt for a ride, wipe off any excess lube after application.
Give your bike a little grease at this point too. Pay attention to the pedals and seat post.
Remove both the pedals and seat post, then apply the grease where metal makes contact with metal. In the case of the pedals, grease is applied to the threads that screw into the crank arms.
Tip: Don't have a repair stand? Don't worry! Just lay your bike against a wall, hang the seat over a thick tree branch to suspend it in the air or use a bike rack.