Anatomy of a Mountain Bike


This section takes you through all the important parts of a mountain bike, explaing what it does and giving advice on choosing and set-up to new riders and old stagers alike.

Why should I start mountain biking?

Now, I might be biased, but mountain biking is one of the most rewarding, exciting and fun sports you can do. You get the thrills of formula one (don't believe me? Try launching youself down a rock strewn hill at touching forty mph, with nothing but your ability and and a few inches of rubber between you and the ground), the teamwork of football and the competitive rush of athletics.

Take a sunny day, some friends and some bikes and you're guaranteed a fantastic time. Take some British weather, some friends and some bikes and you're still guaranteed a fantastic time, but with added mud!

The beauty of mountain biking is that you get better every time you ride. New hills, corners, and jumps continually improve your riding skills, whilst maintenance, repairs and tuning see your mechanical ability shoot up. You also get fit.

But hey, you can get fit playing tennis. You can get excitement bungee jumping. What you'd miss out on is the experience, the independence and the adventure that getting out there and seeing new bits of the world gives you.

You might think you'll just ride your local forest, or you'll only do street and trials, but sooner or later you'll want to check out other forests, or you'll hear about some wicked drop off's a few miles away, and you start riding further, maybe get a lift, catch a train, maybe make a holiday of it with your mates, maybe get so good you want to start racing and travelling to catch the whole series…

And before you know it, you've seen so much, got life affirming experiences under your belt you wouldn't give up for the world, and you're a mountain biker first, and a student/bankmanager/mum/whatever second.

How should I start?

Obviously, this is going to be complicated, so I have employed the following diagram to help:

Okay, so maybe it's not quite that simple, but my point is you can get bogged down in techno-jargon and complications when it's really very straightforward. You need a bike and somewhere to ride it. And a helmet.

No Buts! Always wear a helmet. You don't have to use body-armour unless you're flinging yourself down cliffs, because even if the worst happens, broken limbs heal (eventually). But apply the same impact to your head, and you could die. And that can really ruin your ride.
Helmets aren't geeky- when I'm riding I'll judge another mountain biker for not wearing a helmet long before I check out their bike or their skills. Riding without a helmet says 'amateur' if I'm feeling generous and 'idiot' if I'm not.

The Bike

Buying the right bike can be tricky, but there's loads of choice out there so it should be fun! If you're new to mountain biking, get yourself the best all-rounder you can afford. A good, light-ish bike with front-suspension (a hardtail ) will cover pretty much all bases.There are a lot of full-suspension bikes out there, starting from about £150, but there will always be a weight penalty and the quality of the componentry will be compromised, because the money is being spent on rear shocks, pivots, swingarms etc.

As a first bike, you'll do better to steer clear of full-sus altogether, unless you can spend around £500 or more. Below this price bracket, the compromises are really too great, and you'll be a much better rider if you learn the groundwork on a hardtail or even a rigid bike first.

There are several key things to think about when buying your mountain bike:

The Frame. This is number one. A decent frame that warrants upgrading the other componets at a later date is a great investment. When you've been riding a while you'll be in a position to see how much riding you do and so how much you're willing to spend on getting you're bike just right.
You'll also have an idea of what kind of riding you like best and adapt key areas of your bike for it. For example- really getting into trials and tricks? Maybe you'll want to fit wider bars or a chain device. Thinking about racing cross-country? Could be time to fit some stronger, lighter wheels.

Get the right frame and you leave these and many more options open to you.
The main consideration when it comes to frames is weight vs. strength. The lighest, strongest frame is what you want, and generally this means Aluminium. Don't rule out Steel frames, though. Steel is heavier than Aluminium, but it does have the advantage of being repairable and is slightly less stiff, and more 'springy'.
With all frame materials, look for butting (varying the thickness of the tubes at stategic points to save weight).

The second most important consideration. They don't always look much, but a light, straight wheel transforms a bike and lets you really appreciate the frame. A heavy, bent wheelset can ruin it.

Now for the science bit. Rims, hubs, inner tubes and tyres make up a fair part of the bike's weight. But where wheels are concerned there is also the issue of rotational mass. Without getting too technical, this means that when the wheel is rotating it weighs more that if it were standing still- so this is a crucial place to save weight.

Unfortunately, this is also the point where bike meets ground, so it needs to be strong, too. A good, hand-built set of wheels (where each spoke is tensioned by hand, not machine) is the best, but when you're checking out the bike in the shop give the spokes a quick tweak- do they feel tight and even? Does the wheel run true? You'll notice it on the trail if they aren't.

The Components. Very important, but it's lot cheaper to replace a derailleur than the frame. The beauty of mountain bike running gear these days is uniformity- nearly all bikes feature Shimano mechanicals, and the ones that don't have SRAM (gripshift). Which you prefer is entirely down to you, though twist grip systems are a lot easier to get your head around if you're just starting. Either way it's all good quality and smooth running, and you can't really go wrong, but the higher up the range it gets, the lighter and stonger it gets, and the higher the price tag.

Finishing Kit
Here we're talking about saddles, handlebars etc. As with so much when it comes to bikes, lightness and strength are the keys issues. But make sure it's comfortable and feels good to start with. You can adjust and change things later, but in the beginning you should at least be able to work with it.

There are two types here- rim brakes or disc brakes, and three variations.

On sub-£500 bikes you'll generally only find V-brakes. These work on a cable system that pulls the brake pads against the wheel rims when you pull on the lever. The V-brake system works so well you may never look any further, though cables do eventually stretch.

Then there's hydraulic rim-brakes, a favourite of trials riders, where hydraulic fluid rather than cbles activate the brake pads. Offer a better 'feel' and no cable stretch, but are much more expensive and don't really outperform a well sep-up V brake.

Finally, there are disc brakes. These operate by applying the pad to a metal disc around the wheel axle. This cuts out the problems of mud, water and wobbly wheels affecting the rims, and thus reducing the effectivensss of rim-brakes. They are the most effective and provide the best feel, but you really need to spend money on them.

On a first bike, I wouldn't look beyond V-brakes. Like full-suspension, cheap disc brakes are often offered on lower priced bikes because of their image, not their performance, and money spent on flash but poor brakes is money not spent on the frame, wheels, gears etc.

When you've worked all this out and decided on your dream machine, don't throw all that hard work out the window and get the wrong size. If you've had other types of bike, don't try and apply the same sizing rules to an MTB. Mountain Bikes are designed to have a smaller frame and a higher saddle, giving plenty of standover height. Should you have a trail incident this gives lots of clearance between the frame and you, saves weight and generally provides a more manouverable frame. You should have about 2-3 inches between you and the top tube when standing flat on the foor, and be able to sit on the saddle and touch the ground with your toes outstretched.

So, have you got all that?

There's a lot to take in when you start thinking about getting a mountain bike. Take your time, find a shop you like and get as many opinions as you can. Be warned- people tend to lose their impartiality when it comes to their bikes! If they say that X bike is the best, ask them why, and what others they'd recommend. Look at reviews, get your hands on a magazine or three and do your homework. Mountain Biking UK has the most informative reviews, but those in Mountain Bike Rider (mbr) are great too and if you're thinking of getting a downhill bike check out Dirt.

Have fun, and remember- the most important thing is to get a bike and ride. I guarantee you won't look back.

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