Stock or Mod bikes (26" or 20" wheels)?
24" trials bikes
Long or short?
Bottom bracket height?
Rear derailleur useless?
Suspensions or not?
Why a low seat?
Why no Clip pedals?
Why disk brakes on the front?
Checking the bike
Bouncing on the back wheel
Endo, or balance on the front wheel
Lifting the bike in the air (bunny hops)
Lifting the front wheel
Landing sharp on the back wheel
Pressure for the tyres
Protections and Safety
What is a Zone?
Also check out the excellent video guides made by Adam himself from TartyBikes, about choosing bike components and assembly tips.
Stock or Mod? With so many makes around, each offering stock or mod models, choosing your first bike is not really easy. If you are quite small, the mod (with 20 inch wheels) is usually an easier platform to start with.
Mods are very bouncy. In the early days of biketrials, these were bmx-type 20" size wheeled bikes modified for riding trials (Mods). So they are more reactive and you can maneuver and move your body around without feeling stretched. They are also more sturdy and can take more abuse (because of the integrated bashguard, the single-speed design with no rear-mech to trash, the smaller and stronger frame, stronger wheels...) Also, as a starter bike, a Mod is probably more rewarding. The very short chainstay makes it very easy to hop and balance on the rear wheel. They are easier to sidehop with, even if it is to land randomly on the bash plate. They are lighter than stock bikes and tend to cost less too. They have no other use than riding trials (the very small gear ratio means you can't really use it to commute anywhere, like you could with a BMX), but they take less room if you are short of storage space.
The stock bikes in comparison were 26" wheeled mountain bikes optimised or customised for trials. This meant riding on a small frame geometry, lowering the seat, taking out one or two outer rings and adding a chainring protection. You could still use it for riding in the woods. This was the old-school approach. You can still start a few moves of trials on a regular mountain bike, but you will soon find some limitations due to frame geometries. The new generation of stock trials bikes have geometries so specific to trials that you canīt really use them for anything else. They come with reinforced and shorter chainstays, sturdier tubing and they will last you much longer than a regular mountain bike, at least in a zone. The new geometries can look a bit odd, but you can still buy most of the spare parts in a regular bike shop, and they will make a huge difference to ride trials (especially to balance on the rear wheel). They allow to fit much larger tyres up to 2.5" wide, and most frames donīt even have a seat option. If you are tall, you can ride indifferently a stock or a Mod bike, and it is really down to personal preference. With the 26" wheels, the stock bikes roll more easily, giving a smoother riding experience. Also, the longer frame means you have more reach with the front wheel, when bridging over a gap, or for most techniques landing on the front wheel. The cool thing about stock bikes is that they can look more like ordinary mountain bikes (especially if you have a frame that can take a seat) and passers-by won't confuse your stock bike with a BMX. If you run several speeds, then you can commute to your favourite riding spot much faster than with a Mod.
Now what with 24" bikes? That's the new trend, the optimum mix for street trials. Some champions, equally at ease on Mod or Stock bikes argue that 24" trials bikes would bring the best of two worlds together. More reach than a Mod bike for front-wheel moves and hooking techniques, and more manoeuvrability than 26" Stock bikes while being stronger and lighter. There are relatively few manufacturers of 24" trials bikes (you usually find this size of wheels on dirt or jump bikes fitted with a suspension fork). But there is a promising future with frame builders like Inspired Bicycles.
The best way to decide is to try out different bikes... problem is... so far, you won't find these bikes in regular mountain bike shops. On the Trials Forum, find out if there are some local riders you can contact and meet up with. I only ride a 26" stock bike now because I started with the mountain bike I had at the time. I tried mods and they are really a lot of fun, but I still prefer my stock bike, because it feels more fluid and less quirky.
Long or short?
As if it were not enough, you can choose from different geometries for both Mod and Stock bikes. Typically the longer geometries, with a wheel base from 1070 to 1100mm (the distance between the two wheel axis) make it easier to tap the front wheel onto obstacles, and to land on the front wheel. The shorter geometries (wheel base less than 1070mm) offer more spin, to turn around and pull out some street-moves... By changing the stem/handlebars combination, you can adjust your position on the bike to your exact liking. The chainstay length is also a critical specification, it ranges from 375mm (very short) to around 430mm for stock bikes. The shorter the chainstay, the easier it is to balance on the rear wheel.
Bottom bracket height?
The Bottom Bracket height (above or below the weel base line) defines the feel of the bike. The modern and long geometries tend to have a high bottom bracket (varying from +15 up to +60mm on some frames). That gives more clearance for obstacles, but makes it more difficult to pull bunny-hops types of moves. You just get used to relying more on pedal-power techniques. Once you balance on the rear wheel, the bikes feels the same, but you have a higher reach for sidehops (because your whole center of gravity is higher).
Why disk brakes on the front?
For the front wheel, the disk brakes are very progressive, and its very useful when rolling on the front, to control totally a move. Also they offer stronger braking than rim brakes because the fork doesn't bend out under stress. The rim brakes on the front will end up breaking the fork (because of the force pressure into the brake pivots). The V or the rim magura on the rear stop the wheel at any rate, even on an edge or a slope, on the rear wheel. You need that for safe trials, else, a weak rear brake throws you on your back. You don't want something too progressive, but a blunt stop.
What you need is plenty of room to move around the bike, to balance and to manoeuver. That summarises in a small frame, (usually the smallest available) and a combination of high rise stem and high rise wide handlebars. The length of the stem is determined by how much stretched you want to be on the bike. Wide handlebars give you more torque (strengtht) and more stability.
On a regular MTB, the seat should be adjusted to the lowest position. When riding trials, its not necessary to shift gears, and you can set the gear to a nearly 1:1 ratio (from crank to cassette). Typically ratio in the number of teeth are 22/19 or 20/17 for the front ring and rear sprocket. If you ride a pure trials bike, then you'll probably be riding with a 18t front sprocket, with a 16 or 15t rear sprocket. You may feel really uncomfortable and unbalanced at the beginning, but this is at this kind of ratio you'll end up if you want to pedal kick, or backhop. The tyres should be as big and fat as the frame spacing can take (up to 2.5" wide is common).
Making a bash ring
If you only use the granny ring on a normal crank (set for three chainrings), you can get rid of the larger rings and replace them with two cheap steel medium rings. Then you have the smallest chainring protected by two parallel medium rings that will also grip on most edges.
Rear Derailleur Useless?
In Trials, the gear shifters and rear derailleur are never used. It used to be that for competition purposes, you had to keep at least 6 working speeds. Then most riders changed the cassettes with the smallest lightest sprockets and only left a larger one to use. In 2007, the rules changed and allowed for single speed bikes with no gear shifters on the bars. The frames require either a chain tensioner or an adjustable nut on a horizontal drop out for the rear wheel.
Bouncing on the back wheel
After a small endo, move your body backward with the rear brake on, and lift the front wheel in one go. Then on the back wheel, knees folded for a jump impulse, jump on site while extending the arms. In the same second, lift the handlebars higher by pulling the bars back to you, and lift the feet to let the bike follow at the same time. In the beginning, you will hop backwards, because of balance problems. Its a lot of synchronisation. Once you get to two hops, you are on the right way.
Checking the bike
First the brakes should block when pulled to the max. And if you have cables, pull to the max and make sure the cable is not on its way to break. Then the handlebars and the stem, pull on each sides, check there is no move, nor too bad creaking noises. Then the crank, there should be no play in the bottom bracket, nor between the crank levers (if you have alloy levers and they round-off a little bit, you can adjust the play by inserting some small aluminium sheets 10x13mm cut out from a recyclable aluminium beverage can. For the chain, it should run smoothly and fluid without bumps or jumps between the different gears. If two chain bits are not pivoting properly, use a chain tool to unlock the pin. Any part on a bike can break, but a frame or a back wheel wrecked into puree are still much safer than a bumpy chain that suddenly jumps or breaks when you kick in.
Why aren't clip pedals recommended for trials riding?
Because Its way too dangerous to have your feet stuck when you need to jump off the bike at any time for a safe crash. You'd rather land on your feet than on your back, believe me.
Getting on the front wheel
Moving at a slow pace, just apply full brakes on the front wheel. While the bike stops, carry on moving your body forward and above the handlebars by naturally folding your arms (you carry all the inertia and energy of the system 'bike/rider'), and then push on the handlebars at the very last moment. At this stage, your weight should be mainly above the stem, and pushing on the handlebars will put the bike on the front wheel. At the beginning, don't go too fast or you'll go over the bars (remember, it's about balance, not about crash speed). If things go wrong (going over the bars), don't release the brakes or you'll bite the rocks. Just put the feet back on earth, on each side of the front.Once you get it right, you can try a few hops on the front wheel (like dynamic push-ups), or carry on riding on the front wheel by releasing the front brake and staying in balance above the stem (really difficult, it helps to be in a light slope).
How to lift the bike in a bunny hop or back hop, or side hop?
Lifting the handlebars is the only trick, because your feet can't lift the bike. It looks like the feet are stuck to the pedals, but in fact they are just limiting the ascension of the bike. The higher you lift the handlebars, and the faster you push them forward afterwards, with a forward twist of the wrists to force the whole frame to follow, the higher you can get the back wheel off the ground. Of course you need some synchronisation, this is the difficult bit that needs hell of practice. You can practice with full brakes on (the safest way to understand the move). That leads you to the back hop.
For the impulse to jump, think about it like jumping on your feet without a bike. You need to flex the knees, then full extension. On the bike, same business but with synchronised pull on the bars upwards to lift the front wheel while still in extension. Once you are fully extended, it's time to lift your feet, like you do to jump over anything. At the same time you are lifting the feet, you need to twist the handlebars forward (its the only way the frame can follow, the entire bike rotates forward in a vertical plane). All the move takes less than a second.
How to lift the front wheel for a pedal hop or a wheelie?
From a low pace for the wheelie, lean your body backward while pulling on the bars and giving a good kick in the driving pedal. That should take off the front wheel from the ground. Once you have the feel, you just need to practice until you know how much to pull on the bars according to the pedal kick. (the stronger the kick, the less you have to pull. You can even lift the front wheel without pedaling (manual), just by pulling on the bars and moving your body really backwards (behind the seat post).
For the pedal kick: from a stand still, same move but more powerfull kick when releasing the brakes, to take off the front wheel and also lift the bike in the air, and full brakes on as soon as the rear wheel touches down.
How to land the back wheel on an edge
Typically, for climbing on a beam or a sharp edge with no support behind to land the front wheel, you need to land right in balance onto the back wheel, without dropping the front wheel. You'll need quite a lot of practice for that, but the trick is to bunny hop at very low speed and nearly vertically, so that inertia does not force you over the obstacle. You need to lift the front wheel to the maximum and stay backwards rather than pushing forward like for a normal bunny hop. If you overdo it, then you'll probably have to hop back. Off course, you need to have the rear brake 'full on' when you land the back wheel on the edge. The best is to practice on a kerb that is about as high as you can bunny hop, with some plain ground behind.
Why a low seat?
The lower the seat, the more margin you have to move around the bike.On certain moves (climbing or landing) you need to be very streched backwards on the bike, nearly seating on the rear wheel, and a high seat would punch you through the stomach (on mod trials bikes, there nearly no seat, just a flat cap mounted on the frame). Anyway, you never sit when riding trials, so the seat is more like a protection from the frame tubing. Most trials specific bikes don't even have a seat option.
What pressure for the tyres?
It depends on the ground and the sharpness of the edges you climb on. The sharper the edge, the more inflated you want the tyres so that you don't get a double pinch flat when banging the back wheel on it (the unfamous snake bite, rim rails pinching the tube against an edge). For round blunt obstacles like wood logs, less pressure gives extra gripping because the tyre can litteraly grab the edges and shapes. less pressure also gives extra bouncing for landing, and is more comfortable. Fat tyres (2.5" or wider) are the best, and allow a lower pression than thin tyres, so more comfort and more grip.
How to practice balance?
Ride very slowly upwards a very smooth slope, and go slower until the bike actually stops without the brakes. Then try to maintain the bike on the same spot by adjusting the pressure on the driving pedal (right foot most of the time). When you feel that you are loosing balance, kick in the pedal to carry on or twist the handlebars to get extra balance. The next step to understand balance better is to let the bike go backwards in the same slope, by decreasing the pressure in the pedals. This exercice is easier on a medium gear ratio.
Why no suspensions in trials riding?
Because its a drag. All the impulses you give to hop around tend to be absorbed by the suspensions, and the back wheel doesn't take off. The suspension fork takes your energy on simple moves, and makes things more difficult to balance, because you have to compensate for the ongoing swinging of the fork. You can still do with a front suspension, tuned to the hardest setting. And its extra weight and money.
OK, the obvious one is the helmet, I know its boring, too hot, uncomfortable etc...but after a few crashs on your back (the most common in trials riding, due to bad timing with the rear brake), you'll realise how close your head can get to the rocks. Solid gloves, (the heavy braking involved wipes the skin out). And shin guards, to stop the pedals from grinding your tibias when you lose control. Always start small before you build the height. As a general fact, all the techniques described in that Website can be practiced from the edge of a 6 inches kerb, along your home street, until you are confident enough to try from higher.
What is a zone?
In trials riding, a zone is a guided track full of obstacles to climb on. To pass a zone, the rider must follow the tracks without putting the feet on the ground, otherwise he gets penalties.