Different bike types

By Owen Coutts | Friday, July 23, 2010 1.17pm

Back in the early days of the MTB, the bikes weren’t really very good at doing what they were meant to do. Sure, they were fine by standards of the day, and by the vague standards of the comparisons we had – beach cruisers and cyclo-cross bikes. But MTBs back then are miles apart from those of today. Fast developing rider skills meant that we got by and we learnt from mistakes. Bit by bit, though, the bikes improved, but it took a good 20 years or so to fettle and tune the species, at least to where we are now. Who knows what the next 20 years will bring.

The development of the species – and its confusing array of sub-species – has resulted in the mountain bike becoming a thoroughbred do-anything multitool. Downhill bikes have evolved to a degree where untrained eyes simply see them as motorbikes without engines, while most other MTB genres have become totally accessible to mere mortals. From town bikes to jump bikes to cross-country (XC) race bikes, the tool the MTB has become somehow manages to satisfy its multitude of users as perfectly as an adjustable spanner.

A ‘hardtail’ has front suspension only and is the ‘traditional’ enthusiasts off-road bike. It was only about 10 years ago that the suspension fork made its mark and now it’s on almost every MTB. Even low budget XC bikes are hard to find with a rigid fork. At the top end, hardtails are being out-hyped by full suspension bikes, but lots of riders still love the relative purity of the lightweight hardtail. It’s a very relevant speed option and it still attracts riders at every price point.

With average generic aluminium frames (most are made from alu) weighing well under 2kg (4.5lb) and the lightest weighing less than 1.5kg (3.3lb), it’s no surprise that the weight wary usually ride hardtails. The lightest suspension frames tip the scales at about 2.5kg (5.5lb) and most are a fair bit heavier. It’s not unusual to find a racer on a hardtail that weighs less than 9.5kg (21lb), but an average mid-range bike still weighs about 11.5kg (25.5lb). It’s the parts that makes the difference. Top end parts are nearly always quite a lot lighter than moderately priced ones. For example, a pro race level XC fork will often weigh 0.5kg less than a fork on a mid-range bike.

Steel frames have fallen out of favour over the last five years or so, but they still have their fans, as they’re often said to have more ‘feel’ than alu frames. ‘Feel’ is hard to quantify, but there’s no doubt that alu frames usually feel harsher over bumpy ground, relying on bigger tyres and well padded saddles for comfort. Titanium and carbon-composite hardtail frames also offer a superb ride feel (like steel, titanium and carbon have more shock absorbing qualities than alu), but they’re costly. Tubular magnesium frames are gaining favour in some quarters, mainly because they offer a low-vibration ride feel and they’re very light, but it still hasn’t been generally accepted as a frame material.

It’s the build simplicity and riding ‘purity’ of the hardtails that’ll ensure their survival in a market increasingly dominated by suspension bikes. Many riders love the fact that hardtails put you more directly in contact with the terrain and pedal power. You may feel the bumps more, but you learn to ride with a level of grace and finesse that helps you to tame the terrain. Learn to ride difficult terrain on a hardtail and you’ll be a better rider in the long run.

The ‘ordinary’ mountain bike is the bike most people buy. Okay, there are all sorts of sub-genres like hybrids, comfort bikes and adventure bikes, but most of them are simply comfortable non-specialist machines that encourage you to have a go.

This is the bike that has made the MTB into a mainstream bike for every man, woman or child. It’s the generic entry-level MTB that’s given birth to all manner of sub-categories for those who really don’t want a thoroughbred, fat-tyred off-road bike. The ‘ordinary’ MTB ranges from the perfectly adequate suspension fork-equipped trail bike to the commuter bike that simply borrows the best aspects of MTB technology.

Adjustability and adaptability is the key to the ideal starter MTB. Not everyone wants a handlebar, stem and saddle in the same position, so look for a long seat post, fore/aft saddle rail adjustment and height adjustment in stems. When a stem bolts straight on to the steerer, look for washers on top of the fork steerer. These can be placed over or under the stem for height adjustment.

The majority of entry-level MTBs will be fitted with a suspension fork. If you want a bike for urban use only, look for one of the few with a rigid fork. Suspension offers more comfort and damage limitation on pot-holed urban streets, but you’re better off saving a bit of weight and money and investing in better tyres, mudguards and a rack.

XC racers took ages to be convinced that the weight of suspension forks was a burden worth carrying for the sake of comfort, damage avoidance and control at speed. But as forks got better, more riders started to use them. Now the same’s happening with rear suspension. The designs have improved to a level where even the top XC racers will often choose full suspension bikes.

The racer obsession with lightweight bikes comes from the fact that races are often won or lost on climbs. A lot of full suspension bikes climb well – often better than a hardtail on a bumpy climb – but the frame/shock weight is still seen by some as a problem on smooth climbs. Minor speed lag is no big deal for mere mortals when fun is being had elsewhere, but it can be enough to cause a racer to lose contact with a climbing group.

A well designed and well set-up full suspension bike offers a big advantage as soon as the going gets rough. Its potential for speed on any rough ground, its improved control and its extra comfort makes a small amount of extra weight worthwhile in most situations. There are times when a full suspension bike will tackle the rougher climbs better than a hardtail because good rear suspension designs produce the sort of boost in traction and control that allows you to pedal harder and carry speed.

Early XC full suspension bikes were often flawed by poor designs, excessive weight and dubious durability. Over the years, though, weights have come down and designs have improved to the point where the oft-discussed ‘energy robbing’ of suspension has become minimal enough to ignore. Any slight energy loss and weight gain must now be weighed up against rider energy and speed gain, through increased comfort, traction, confidence and control. There are loads of different ways to design an efficient XC full suspension bike. These days, most designs are well sorted and many of them – for those who still worry about energy being robbed – offer instant lockout capability on the rear shock, either on the shock itself or via a thumb shifter control on the handlebar.

While most top end XC bikes are built with race performance in mind, the manufacturers know that most of them are bought by riders who rarely, if ever, race. The most expensive XC race-bred full sussers might weigh as little as 10kg (22lb), but the more accessible mid-range bikes usually weigh somewhere between 12-13kg (27-29lb). The frame designs range from pivot-free (the chainstays flex) ‘softtails’ with under 50mm of travel to a multitude of single-pivot and four-bar linkage designs with between 70mm and 150mm of travel.

Trials bikes, not to be confused with trail bikes, are bikes that’ve been modified – or sometimes specially made – for riding challenging urban or rural obstacles. You could have a go at trials on any bike, but there’s a special breed of modified MTB that’s not much good for anything else.

Special trials MTBs usually have 26in wheels, but some use 24in. MTB trials are generally kept separate from the ‘traditional’ 20in wheel bicycle trials, although there’s some overlap because many riders are good at both. In theory, an MTB can be turned into a trials-ready MTB just by dropping the seat. Replacing the big chainring with a bash ring gives you more clearance/protection for hopping onto/over obstacles. Fitting bigger tyres and running your tyres soft will give you more traction, but for the more radical manoeuvres, the frame, fork, wheels and componentry need to be strong enough to deal with impacts with solid objects.

There are trials competitions for both MTB and 20in wheel bikes, but most riders will just hang out and play on street furniture. Steps, fountains, fences and bollards are all as enticing to an urban trialster as roots, rocks and drop-offs are to a rural one. Big drops and gap jump stunts are best achieved with the sort of nonchalance that implies total spontaneity rather than the reality of months of unseen practice, frequent failure and injury.

Trials riders break lots of stuff. Non-reinforced MTB frames tend to break behind the head tube, halfway along the top/down tube or near the bottom bracket. Steerers might bend when subjected to big impacts and normal bottom bracket axles and cranks may snap. In fact, anything that’s not specially made to take abuse won’t last long in a trials situation.

Despite initial big ‘n’ bouncy have-a-go appeal, purist downhill bikes are bought by relatively few riders, so it was only a matter of time before the more practical breed of the go-anywhere/do-anything Freeride bike evolved. The basic notion is that Freeride bikes and their riders are a partnership with a ‘can-do’ attitude. If something looks even vaguely rideable, it’s worth trying. At the lighter end of the market, the bikes are essentially big hit XC bikes with plenty of suspension.

Freeride bikes go downhill almost as well as specialist downhill bikes, but they cope well with uphills, too. Pedalling efficiency is more crucial than on pure downhill bikes, so the frame and suspension design will usually be position and travel-adjustable to suit whatever terrain you choose to tackle. Most Freeride bikes will be fitted with a range of gears that can deal with extreme ups as well as downs.

At the hardcore end of the Freeride spectrum are big hit/big drop bikes aimed at risk takers – riders who jump off seemingly impossible drops, ride over and off all sorts of natural and manmade obstacles – seeking out the sort of terrain that no ‘ordinary rider’ would go near. This sort of riding is often referred to as ‘North Shore’, after the imaginative trails and log constructions on parts of Canada’s Vancouver North Shore.

Freeride bikes might offer as much suspension travel as a downhill bike (occasionally more), and some pure stunt machines could weigh 22kg (49lb) or more. The more typical Freeride bike will vary between a ‘Freeride-Lite’ 14kg (31lb) with 100-150mm of suspension travel and a harder-hitting 17kg (38lb) with 150-180mm of travel and heavier duty componentry.

There is no accepted Freeride norm. Technically, it’s probably the fastest-growing area of mountain biking. Thoroughbred Freeride bikes at the leading edge tend to cost a lot of money, but the trickle down effect of the technology is that it’s increasingly making room for reasonably-priced Freeride styled bikes in lower price brackets.

Some would say that buying a bike with a Freeride tag is more a fashion and attitude statement than anything else. Few riders can push these bikes to their limits, just as few four-wheel drive vehicle owners push their vehicles to their limits. But there’s nowt wrong with buying a bike to suit your dreams and aspirations. While a Freeride bike may be a fair bit heavier to haul up hills than a ‘normal’ XC full suspension bike, it’ll readily forgive rider error and can offer the sort of big hit ability than would probably damage a normal MTB. For many riders, the fun of riding lies here rather than in hill climbing speed.

It’s not easy to pigeon-hole this bike type. Slalom, BSX (Bicycle Super Cross), Biker Cross, Mountain Cross, Dirt Jump… the bikes are essentially BMX attitude encompassed in a mountain bike. There are minor differences between the bikes for each discipline, but in essence one hardcore bike type can tackle all.

Strength in frames, forks and components is an overriding feature of such bikes. Everything needs to be capable of taking the sort of abuse that few other bikes suffer. The frames are compact with thick walled tubes, boxed sections and lots of reinforcement features. Aluminium is the dominant build material, but steel makes more sense and it seems likely that steel frames will make a comeback. Forks, wheels and the rest of the components are heavily built in order to take inevitable crashes and bad landings.

Confusingly, all these disciplines feature both hardtail and full suspension bikes and there’s no real consensus about frame geometry or gearing. Some riders choose to ride a single gear on a rigid frame and fork, others choose a hardtail with a long travel fork, others choose full suspension. Some bikes have 24in instead of 26in wheels and no one can decide whether the frames should be short or long in terms of reach.

The main thing that characterises the bikes is tough build quality, or simply hardnut imagery where some of the ‘me-too’ low budget jump bikes are concerned. The preference for a low saddle, while not a practical choice for getting to places, signifies a readiness for the sort of radical manoeuvres that the bikes are made for. Many of these bikes, at least the hardtail versions, can readily double up as urban playtime machines.

As with BMX – and downhill to an extent – many of these bikes are bought by riders who simply like the image and attitude that the bikes suggest. Among those who abuse the bikes to a level somewhere near what they’re capable of, there’s a wide array of styles and ability. Some riders just love to hang out at jump spots, without a hope of being able to achieve much more than a small bunny hop, while some perform stunts with a style that suggests circus training.

For many riders, riding a bike fast downhill is what mountain biking is all about. While you obviously have to make your way to the top of the hill in the first place in order to savour the plummet, descending hills doesn’t necessarily require massive athletic prowess – although you’d be surprised at how much training a downhill racer does.

Downhill bikes appeal for all sorts of reasons – the thrill of speed, the necessity for skill, the need for concentration and instant reaction to fast approaching obstacles and the trail – and they’re all factors that conspire to create the sort of buzz that can only come with potentially risky activities. Of course, the real buzz comes from successfully dealing with the risk.

Pure downhill bikes haven’t really been a big commercial success. A lot of them are bought via low-cost sponsorship deals, by racers who then proceed to wreck them in competition practice. Hardly any specialist downhill bikes remain popular for more than a season or two, and those that you come across on the secondhand market will often have been subjected to almost terminal abuse.

Pure downhill machines are a specialist breed, not suited to the sort of terrain where the forces of gravity are not in your favour. They’re designed to absorb big hits from the harshest rock-strewn terrain and that will often mean loads of extra weight, and somewhere between 150 and 300mm of plush suspension travel, dialled in for damage limitation rather than pedalling efficiency.

There is no one frame or suspension design that typifies downhill bikes. A 16kg (35lb) single-pivot bike with about 160mm of fork travel and 180mm at the back may be perfect for some courses, while others are best served by a 20kg (45lb) multi-linkage bike with 180mm of fork travel and 210mm at the back.

Just as bikes vary enormously, riders do too. Even among racers, there are some who perform superbly on highly technical and super-steep courses on slimy surfaces, whereas others appear to need fitness-based courses with good traction. The real stars are capable of winning on any sort, where natural ability, fast reflexes, full body fitness and thoughtful bike, tyre and part choices are as crucial as nerve. Pay no attention to anyone who says downhill racing is a brain-disconnected thing. If that’s your approach, you won’t last long.

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