MTB Maintenance – Keeping Your Bike a Well-Oiled Machine

The bicycle is an incredible machine. But like any machine, the moving parts wear out and mountain bikes have a lot of moving parts. This article will show you how to do your MTB maintenance.

The amount of stuff you have to watch out for can be a headache for even the most experienced mountain biker and downright daunting for a newbie. This doesn’t mean that mountain bikes are particularly difficult to maintain – you just have to know what to look out for.

The following are the most MTB maintenance intensive systems on the bike are likely the areas where you will first encounter wear and tear or problems on your new bike:

The Drivetrain

This intricate set of moving parts is one of the most maintenance intensive parts of the bike. It’s complicated, under a lot of strain and completely exposed to the elements but drivetrains are more resilient than they may seem.

Most of the drivetrain maintenance comes down to taking care of these parts:

1.The Chain

The chain transfers the entire force of your pedal stroke to the rear wheel. But it actually gets most of its wear and tear from shifting and skipping.

Maintaining the chain requires that you know the difference between the two types of lubricant: dry lube and wet lube. Dry lube is designed to keep the chain sliding smoothly and clean in dusty conditions.

Mountain bike chain
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It’s the safe choice for lube since the only consequence of running it in the wet is it washes off the chain. Wet lube is designed to keep the chain lubricated by keeping water out of the moving links.

Avoid using it in dusty conditions since it tends to make dust stick to the chain which can be very difficult to wash off completely.

Despite their price and metal construction, chains are actually a consumable component. They elongate over time and lose their tolerances.

Big budget racing teams in both XC and DH even dispose of their race bike’s chains on a daily basis and sometimes every run.

Chains have a life span that is dependent on how much you abused them and how robust the chain is. A noisy drive train and sloppy shifts are symptoms that your chain is starting to wear out.

There are some objective ways to measure how worn out a chain is but they require some specialized tools that would be tough to come by in all but the most well-equipped bike shops.

2.The rear derailleur

This is the heart and soul of your drivetrain but is also one of the most exposed bits of machinery on your bike. The initial setup is quite easy and there are more than enough tutorials that cover setting up a rear derailleur, but there are circumstances where the derailleur is at risk of losing its smooth disciplined shifting.

The first is when you remove and install the rear wheel often, which can be a necessity for many during transport and storage. This has you resetting the whole wheel-to-bike interface and the tolerances in the setup just aren’t tight enough where you will get the setup exactly the same again and again after reassembly.

Keeping your bike in one piece will give you a higher likelihood of keeping everything aligned for as long as possible.
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The other circumstances that can mess with your derailleur tune are impacts with the derailleur, shifter or things getting snagged on your shifter cable and pulling it.

This can lead to your shifter cable being pulled through its pinch bolt at the derailleur just a little bit, or the limit screws being pushed out slightly, dented or bent. Any of these can mess with your entire shift setup but can usually be remedied with resetting the setup of the derailleur.

The next item has symptoms that manifest in rear derailleur performance but is enough of a head ache that it deserves its own section.

3. The Rear Derailleur Dropout

There is no other piece of the bike that is more hated than this little attachment. The derailleur dropout is found on most frames and is technically a part of the frame.

It is a removable, disposable part that is designed as a fail safe that will give way before the frame or the rear derailleur. Although its mission statement doesn’t sound like something to complain about, its implementation often leaves people scratching their heads in frustration.

The dropout is often a problematic item because it can be prone to bending slightly or breaking entirely. This differs from frame to frame since some dropouts are designed better than others.

But the problem is still persistent because of the fact that the dropout is essentially designed to be a breaking point. This wouldn’t be an issue if dropouts are often unique to every model of frame.

If you don’t have a great distributor network or a well-stocked online retailer, you may be forced to wait weeks for a replacement or even to fabricate your own if the dropout for your bike isn’t stocked anymore.

The derailleur hanger is an inherent, designed weak point that is getting more flak lately because derailleur clutches and long derailleurs for wide range cassettes put more force through this little piece.

Symptoms of a bent dropout are usually easy to see. The jockey wheels of a derailleur should be parallel to the cogs on the cog set. If it is not, you likely have a bent hangar.

There are tools that let you re-align your hangar, but I would recommend you get yourself a replacement as soon as you find out that yours is bent. Dropouts are usually made out of aluminum and aluminum is permanently weakened by deformation.

A deformed hangar that is bent back to its normal position runs the risk of easily getting re-bent or failing entirely – and possibly taking your expensive rear derailleur with it.

4. The Frame

The bike frame holds all the components of the bike together and, in turn, gets a lot of punishment throughout its life span. A key advantage of hard tail frames is that they are very reliable and require almost no maintenance.

On the other hand, indulging in full suspension makes a bike much more maintenance-intensive.

These are the parts of the frame that you have to watch out for when doing your MTB Maintenance:

a. Nuts, Bolts, and Bearings

Full suspension bikes are less reliable than hard tails because having a moving rear end brings with it a lot of complications. Even if we disregard the shock itself, the rear end of the bike rotates on a number of bearings, the number of which depends on the suspension design of the frame.

The symptoms associated with a loose bolt or deteriorating bearings are usually a creak with suspension movement or play in the linkage, which can be felt a small clunk when you lift and lower the bike.

While the symptoms are bearable, you should definitely watch out for them since they can be a warning of catastrophic failure. This could be just a broken suspension or linkage bolt or get as bad as a permanently damaged frame.

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Luckily loose bolts are easy to fix. Thirty seconds and a multitool are usually all you need to do a spot check of all your bolts.

Bearings can get a little tricky though. Diagnosing them can be difficult since a seized or deteriorating bearing may not induce any play. The high leverage in linkage movement also means you will hardly feel any resistance in the suspension motion.

Fortunately, linkage bearings are reliable enough where I would only recommend a preventative maintenance check when there is play or creaks. An exception to this is if you do a lot of riding in wet conditions.

If you do, I would recommend a full bike break down at the end of your wet season to make sure all your bearings are working well.

b. The Headset

The headset is where the fork meets the frame and is basically a set of bearings and their casings which the fork steerer tube can rotate on, much like the bottom bracket.

Problems with the headset are very easy to diagnose. The most common symptom of headset problems is play in the headset when you rock the bike forward and backward with the front brake engaged.

This could mean the headset is just loose and needs tightening.  But if the play doesn’t go away even with a very tight headset or if you feel resistance or notchy clicking while turning your bars, you may need to disassemble the headset and check out the components.

This is actually a very straight forward procedure as long as you take note of how the little parts of the headset fit together. Most headsets allow you to replace bearings.

This is usually enough to fix any resistance or play – which is fortunate since, unlike bottom brackets, headsets tend to be surprisingly expensive.

c. The Seat Post

This part of the bike is not problematic enough to affect performance but is often one of the major causes of squeaks mystery squeaks.

The advent of dropper posts has given a lot of us freedom from constantly lowering and raising our saddle heights but if you’re one of the riders that still do, avoid getting dirt or large grains of sand in your frames seat tube.

A common cause for squeaks is grains of sand getting stuck in between the seat tube and the seat post and grinding up against the frame when pressure is put on the post. If you have a mystery squeak, this suspect is an easy one to cross off the list.

5. Suspension

Moving parts are the bane of reliability. The suspension components of bikes go through a massive amount of twisting and lateral stress. The addition of oil, springs and high air pressure just makes things messier.

Despite this, the comfort and control we get from these systems makes mountain biking so much better and makes dealing with the reliability hit completely worth it.

Modern suspension products are surprisingly reliable given what they have to go through. But how do you diagnose suspension that is starting to give in to wear and tear, and what do you do about it?

a. The Fork

All but the most masochistic mountain bikers have a suspension fork on their bike. This is the more MTB maintenance intensive end of the suspension system because it is both a shock absorber and a structural element of the bike.

But as long as things stay tight and slippery, the fork will do its job. The seals of the fork are its first layer of defense against water and dust.

The first symptom you will see of your seals beginning to fail is a ring of sludge somewhere on your stanchions.

This is actually a failure to keep the oil in the fork rather than a failure to keep the grime out. It is a strong indicator that the internals of the fork are already contaminated.

The remedy for this is to not only replace the seals but clean out the internals and replace the lubricating oil.

Problems in the internals of the fork are rarer but also easier to notice. Resistance in the motion of the fork or harshness can usually be attributed to low lubrication in the spring side of air forks.

Low oil volume in the damper side of forks can usually be diagnosed by turning the rebound to maximum and seeing if it can still slow down the return rate of the fork.

If it can’t it might mean there isn’t much oil left or the oil has lost its viscosity. Both these problems are best solved with a full servicing of the fork which your LBS can do for you or recommend where to send it.

b. The Rear Shock

Rear shocks are much more robust than front suspension because they are often better protected from the elements and don’t have to take the physical abuse that the front suspension does.

They do share the common symptom of a ring of sludge on the stanchion component that indicates failing seals, but all rear suspension servicing should be directed to the service center since specialized tooling is often required to open them up.

6. Brakes

Having brakes that work exactly how you want them to is amazing but it is a state that is surprisingly hard to achieve. Brakes have already come a long way but many rarely maintain their like-new performance after a few weeks of hard riding.

This is especially true for riders who live in climate extremes, especially in the cold and in the hot, humid tropics. If you ride frequently and on lots of descents, keeping your brakes working well is an uphill battle and these are the things you can expect to have to look at eventually.

a. The Levers and Calipers

Cable brakes are getting quite rare but maintaining them is quite easy. Keeping the levers and calipers working well mainly involves keeping the cable nice and clean.

You want it lubricated and free from water inside its housing. Unfortunately, you’re going to be pulling it out and cleaning it a lot, especially if you live in a wet climate.

Putting some heavier grease at the ends of the cables will help keep water out but I recommend wiping it off as soon as it gets dry or risk it getting clogged up with dust.

Thankfully, hydraulic brakes have come down in price and have brought powerful and reliable brakes to the masses.

With all the benefits hydros bring, we get a new headache – break fluid.

This is usually either DOT brake fluid or mineral oil. You’re likely using SRAM brakes, which use DOT brake fluid or Shimano brakes which use mineral oil.

Brake fluid tends to perform better with temperature extremes but the performance drops off very quickly when the system is contaminated with water or air.

Brake fluid is also nasty stuff to work with and can corrode paint and finishes easily. Mineral oil is more forgiving to work with but it doesn’t handle cold temperatures as well as DOT.

Fortunately, these riding conditions are few and far between. Shimano is generally regarded as more reliable than SRAM and the sensitivity of brake fluid is a strong component in that reasoning.

Brake fluid needs to stay clean to perform best but unfortunately, mountain biking components aren’t nearly as reliable as vehicle components.

Maintaining these different kinds of brakes involves generally looking out for the same symptoms and taking the same corrective actions. Brakes contaminated with air or water begin to misbehave on long downhills when the brake system gets hot.

The heat expands the air and can boil the water in the system causing a spongy and vague lever feel.

This forces you to apply more force at the lever to get the same power and can lead to hand fatigue and arm pump.

The remedy for this is a brake bleed. The short version of a brake bleed usually involves pulling out the air and water from a brake system with syringes.

If you don’t get your brakes bled often, I recommend just flushing out the fluid in the system entirely and replacing it.

Mineral oil and brake fluid are cheap consumables but solid performing brakes are priceless!

b. The Rotors and Brake Pads

This is where the stopping happens. Rotors grinding on pads is both our solution to our need to stop but a problem when it comes to keeping our brakes performing well.

While braking power depends a lot on the kind and diameter of rotors and the pad compounds, keeping them powerful completely depends on keeping the contact point clean of lubricants.

Contaminated rotors and pads usually result in the dreaded brake howl.

Getting oil on your rotors and pads can be incredibly frustrating to clean. The pads are usually a complete write off if they get even just a whole drop of oil on them.

Pads are porous and can easily absorb oil. They’re going to have to be replaced if you want your brakes to perform well again. It’s a good thing they aren’t expensive.

On the other hand, rotors are too expensive to replace like consumables and are cleanable.

There are a lot of techniques to getting them clean but I recommend going all out as running contaminated rotors can lead to you contaminating your new pads.

In my experience, the best way to clean rotors is with dishwashing soap and a clean cloth or sponge. Go to town on it and rub it down hard, rinse liberally and clean it with alcohol when finished.

If you have an oven, dry them there at a high temperature and let them cool slowly.

Even after this, it may take some time for the rotors to bed in again, especially if you have new pads.

The moral of this story is never ever get oil on your pads or rotors. Be careful when applying lubrication to your chain, especially if you’re using a spray-on lubricant.

A Final Tip when doing MTB Maintenance

Don’t ride at bike parks, don’t ride in the rain, and don’t ever crash!

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The real tip is: Accept that you’re going to beat the crap out of your bike. That’s what it was designed for and that’s why you bought it.

Don’t let being overly careful with your bike keep you from making the most out of your rides.

MTB maintenance is there to make up for the abuse we put our bikes through.

That being said, the more care you put into your bike, the cheaper repairs tend to cost.

Being attentive to how your bike feels and the kind of sounds it makes goes a long way towards knowing when you might need to address a growing problem and avoid dangerous expensive catastrophic failures.