Beginner’s guide to mountain biking, part 2

How to deal with a cyclist's worst enemy: the puncture

Last month we showed you the basic equipment you'll need to get started in mountain biking. Now you’ve got your kit – whether you’ve bought new or second-hand, hired or borrowed it – the next essential step is to get to grips with it all. 

Mountain bikes have a lot of moving parts and they're designed to be ridden across rough terrain in all kinds of weather, so it's inevitable that sooner or later things will start to break or wear out.

There are plenty of good books out there about cycle repairs and maintenance, but if you prefer a more hands-on approach, a workshop course is a brilliant starting point. It'll help you learn what each part of your bike does, as well as what to do when parts go wrong out on the trail and how to maintain them.

We took part in a great beginner's maintenance course with Paul Peet from Afan MTB, and there are many other companies out there which should be able to help you out.

It felt good to learn the proper names of bike parts instead of just pointing at them or calling them ‘that spinning part there’, and you'll feel more at ease with your bike when you know how it actually works, how to fix it and why it’s important to maintain it.

We'll be covering more advanced topics later on in this series, but for now we'll focus on one of the most common problems for mountain bikers: punctures.

Toolkit

The first thing we learnt was how important it is to take a small toolkit with you every time you ride. As a bare minimum, you should pack a set of Allen keys, two tyre levers, a puncture repair kit, pump and at least one spare inner tube.

When it comes to inner tubes, there are two valve types – Schrader (also known as "car type") and Presta. Some pumps will only work with one type, and some wheels only have rim holes big enough for the narrower Presta valves, so it's important to check what type you have before buying spares.

Most mountain bikes come with Schrader valves like those found on car tyres

The narrower Presta valve also has its fans – make sure you buy the right tubes for your wheels

How to deal with a puncture at the trailside

Punctures come when you least expect them, and often at the worst possible time – like when you're plummeting down a steep hill or pinballing off rocks.

Sometimes they're caused by thorns or broken glass, but more often they're what are called 'pinch punctures'. These occur when you hit an obstacle – often a square-edged step or rock – so hard that the impact forces your tyre and inner tube against the metal rim of the wheel. When this happens, the two edges of the rim rip parallel holes in the tube – this is why pinch punctures are also known as 'snakebites'.

The easiest way to deal with a puncture on a mountain bike ride is simply to fit a new inner tube. That way you can take the damaged tube home with you and mend it somewhere warm and dry, rather than having to scrabble around with chalk, glue and patches at the trailside, often in the rain. To give you more confidence in changing a punctured inner tube, make sure you try it out at home first before you hit the trails.

Step 1: Move to somewhere as safe and dry as possible. Turn your bike upside down – make sure you remove any extra kit you’ve got on your handlebars, such as lights and cycle computers, before you do this. If you have V-brakes rather than disc brakes, you may find it helps to let the air out of your tyres at this stage.

Step 2: Remove the wheel. On most mountain bikes, simply flip the quick-release lever open and turn it anti-clockwise until the wheel is loose enough that you can pull it out. On older bikes with wheel nuts, you'll need to use a spanner to loosen them – so make sure you keep one in your tookit. If you're taking the rear wheel off, shift into the smallest sprocket on the rear cassette (the collection of cogs attached to the rear wheel) first or you'll find the chain gets in the way. If you use V-brakes, you'll have to disconnect the straddle cable across the top of the arms before pulling the wheel out.

Step 3: Once the wheel has been removed, if you have disc brakes, make sure you don't squeeze the levers – without the wheel to stop them, the pads will push out too far. Remove the punctured tube's valve cap and depress the valve to let out all the air.

Step 4: Use one of your tyre levers and, at the opposite side of the rim to the valve, push the curve firmly between the edge of the rim and the tyre.

Step 5: Lift the tyre away from the rim and use the hooked end of the tyre lever to attach to a spoke, securing it. 

  Step 6: Push your second tyre lever into the gap you’ve just created and use it to prise the tyre from the rim. To give you extra leverage, push the tyre lever backwards between each spoke and continue on round the rim, removing one side of the tyre.

Step 7: Find the valve again; you’ll need to push this out from the rim. Some valves are held in place by a threaded nut. You’ll need to unscrew and remove this in order to push the valve out from the rim. Make sure you put the nut somewhere safe though, as it can easily get lost.

Step 8: Pull the old inner tube from the tyre and separate the tyre from the rim. You may need to use the tyre lever to get the other side of the tyre away from the rim.

Step 9: Slowly and carefully run the back of your hand around the inside of the tyre to check for sharp objects – there could be more than one – that may have caused your puncture. Left in place, they could puncture your new inner tube. In the case of a pinch puncture you won't find anything – look out for the telltale parallel holes. If you find a thorn, pull it out from the side it went in – you may find it useful to carry tweezers,

Step 10: A useful tip gleaned from the maintenance course at Afan MTB was to put a small amount of talcum powder into your tyre and gently turn it round so that it forms a protective layer. Then tip out any excess powder. This will help prevent your new inner tube from being pinched when putting the tyre back onto the rim. This won't always be possible at the trailside, but once you've done it once, it should last several tube changes.

Step 11: It’s important that you fit the tyre back onto the rim in the correct direction. Many tyres have direction-specific tread patterns, and fitting them the wrong way round could reduce traction or braking power. Even on tyres that can be run both ways round, you'll have worn the tread in a specific way. Check on the tyre for an arrow, or similar, which indicates the direction that the wheel rotates. The arrow needs to point in the direction of travel, so line it up on the rim with the arrow pointing forwards. To make sure you've got the wheel the right way round, look for the disc rotor, which should always be on the left ('non-drive side'), or, on the rear wheel, the cassette, which should always be on the right ('drive side').

Step 12:  Place one side of the tyre back onto the rim. Take your new inner tube and put a few pumps of air into it to give it some structure, then place it inside the tyre, making sure it's not twisted. Turn the wheel so that the valve hole in the rim is at the top and push the inner tube's valve stem through the hole. If there's a nut on the valve stem, tighten it so the tube is held securely in place.

Step 13. Start to work the second edge of the tyre back onto the rim.  This will get more difficult as you go round the tyre. Use the tyre levers to help work the last part back onto the rim. If you’re struggling, another helpful tip learnt from the maintenance course at Afan MTB was to apply a small amount of Vaseline around the outer edge of the tyre to help you slide it back onto the rim. Once you’ve got the tyre back on, check all the way around to make sure it’s secure and the inner tube isn’t protruding or pinched between the tyre and the rim.

Step 15. Inflate your tube slowly to start with, making sure that it doesn’t inflate unevenly in any part of the tyre. If it does, this indicates that the inner tube has been pinched or twisted. To resolve this, you may have to deflate the inner tube and take one side of the tyre off. 

Step 16. Re-attach the wheel to your bike using the nuts or the quick-release mechanism – make sure to fully tighten these – and inflate to a pressure within the range stated on the tyre's sidewall. If you're re-attaching the rear wheel, you'll need to push or pull the rear derailleur out of the way in order to get the wheel axle into the holes (dropouts) built into the frame. Make sure you put the chain back onto the smallest cog. If you use V-brakes, make sure to reattach the straddle cable.

Step 17: Replace the valve cap and check that the wheel spins freely without catching on any part of your bike. Once you're happy that it’s spinning freely, turn your bike the correct way round. 

Step 18: It’s important to check your brakes are working. Holding the bike so that the wheel you’ve just reattached is off the ground, spin the wheel and apply the brakes. If they aren't working you may need to re-align the wheel in the frame/fork by loosening and re-tightening the nuts or quick-release skewer. Once you’re happy that your brakes are working and the wheel is spinning freely, you’re good to ride.

Word from the author

The staff of BikeRadar, Mountain Biking UK and What Mountain Bike  have vast amounts of knowledge on mountain biking and I’m always left wondering how these guys are so clued-up. Where did they start?

As a complete novice, I had very little idea of what I needed to start riding, or even where I could go to learn how to ride. So I decided it was time to get knowledgeable.

For this series I’ll be riding and writing from a complete beginner's point of view. I’ll visit a variety of locations and take part in skills courses, and then tell you honestly what I’ve learnt.

Follow me through the series and by the end I’ll be aiming to take on the massive challenge of riding down Snowdon, the highest mountain in Wales. This will be the ultimate test of the skills and knowledge I've acquired, and it'll prove that mountain biking isn’t just for the elites!

Next time I'll be looking at basic trail skills and explaining how to deal with another common mechanical problem – replacing brake pads.

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