Berm: Large bank built on the outside of a sharp bend on downhill sections. Allows you to take the corner at far greater speed than you would otherwise. Riding berms as high as you can and with the bike as horizontal as you can is great fun, although rather inefficient. Try: Gorlech trail, Cwm Rhaeadr, most manmade routes above blue grade.
Bleeding: This is either the process of removing air bubbles from hydraulic brake lines (or any liquid-filled pipes), or it’s what you do when you hit the trail harder than you might have wanted. See ‘faceplant’.
Chainring: Cog (or, technically, sprocket, though this complicates things) that the chain runs over mounted where the pedal cranks meet the frame. Normally in a set of three, called the chainset.
Chicken run: A way round a feature. Sometimes a built jump will have a flat trail that leads round the side of it and allows you to miss out the jump completely. That’s a chicken run. Try: Gorlech trail, through the top stump jumping section.
Clipless pedals: Also known as SPDs, but not much anymore. These are pedals with spring-loaded pincers designed to securely lock onto cleats bolted onto the soles of special shoes. Good for climbing, control, and falling gently off as you get used to them.
Derailleur: The mechanism that shifts the chain onto a new gear. At the back, it’s the hanging thing with two wheels in a metal cage with a sprung body thing that hangs from your rear hub. At the front it’s the thing mounted above the chainrings, with a sprung body and a metal guide that the chain runs through.
Disc brakes: Braking system that, instead of mounting pads so that they contact the rim of the wheel, has a caliper mounted near the hub that squeezes a purpose built rotor mounted onto the wheel. This takes the brakes somewhat out of the way of mud and gunk that can prevent them from working properly, means that the wheel can be buckled quite significantly without affecting the brakes, and also opens the way for hydraulic brakes. In terms of physics, the smaller diameter of the brake rotors mean it is more difficult to exert the same amount of braking force on the wheel, but given the greater efficiency that the disc brake setup allows this is more than compensated for. The other downside is that it means adding an extra part – and therefore extra weight and complexity – to the bike, but in practical terms this is not at all noticeable. Disc brakes are universally accepted as being the best setup for mountain biking.
Downhill: A particular form of mountain biking where it’s not so much about heading out into the wilderness with a bike but is more about getting down mountains as fast and as stylishly as possible. A full face helmet and body armour is necessary as the higher speeds and bigger jumps make it more dangerous. Typically you also use a heavier, more robust bike with forks that have a huge amount of travel on them.
Drop off: Trail feature that is essentially a sudden shelf. Usually you ride into them flat, and then the trail drops sharply (over a rock normally). Small ones can be ridden like large rocks, big ones you’ll need to lift the front wheel and let the back roll down. Problematic drop offs can often by identified on manmade routes by the scars of countless chainrings hitting the edge of the rock. Try: Revelation on Penhydd trail, top of Wibbly Wobbly at Bike Park Wales.
Faceplant: Quintessential extreme sports injury. Essentially the bike stops, and you don’t. You sail over the handlebars and for one reason or another can’t break your fall before your face hits the trail. It hurts.
Fireroad: Broad gravel tracks that run through Forestry Commission (and other) worked forestry. Designed to allow logging machinery and rangers to access the forests, but often used as climbs on mountain bike routes. Generally uninspiring and monotonous, but get the climbs done and out of the way without too much concentration.
Flats: Pedals that everyone starts with. Basic, shelf-like things that you can use with normal shoes. Alternatively, ‘flats’ means shoes that don’t cripple women.
Full suspension: Having both front and rear suspension. Front suspension consists of sprung forks, rear suspension in a more complex geometric arrangement that usually involves a horizontal(ish) spring under the saddle. Full suspension bikes should be more expensive (ie. looking at a hardtail and full suspension bike of the same price, the hardtail will be a higher quality bike). They are more forgiving on downhills than other bikes, and can allow you to ride things that otherwise would be tricky. On climbs, they can soak up energy that otherwise would be put into climbing, but locking suspension takes this problem away.
Hardtail: Bike with only front suspension. A nice compromise. Suspension forks soak up bumps as you hit them and relieve some of the pounding that your arms would take on a rigid bike, but at the same time the bike is simpler, cheaper, lighter and stiffer than a full suspension bike. My personal preference, although I’m well aware that could change.
Manmade trail: A purpose built trail usually made with a hard, all weather, all year surface. More or less guaranteed good riding, reliably graded and accessible all year round. Try: everything in the ‘manmade trails’ category.
Manual: Balancing the bike on one wheel. Yes, I know, that’s a wheelie. On the front wheel it’s an endo. Both are manuals, and I can’t do either of them.
Natural trail: Generally, a bridleway, restricted byway, or other legal path that people have discovered is good to ride. Try: Doethie Valley, The Gap.
Pumping: The process of using your arms and legs to react to the bumps, drops, and rises of a trail to achieve the most efficient use of the energy you put into it. See the ‘dynamic riding’ post.
Rigid: A bike with no suspension. Mountain biking on one of these is definitely possible, but rigid mountain bikes are becoming hard to find and unusual to see. The simplicity and budget aspects are probably not worth the hammering and difficulty you’ll experience riding with one.
Rock garden: A bunch of large rocks laid into the trail, which require thought, concentration, and some skill to ride. They range from a fairly simple bit of variation in trail surface to a bad mountain biker’s nightmare. Become extremely difficult when steep, tilted and bendy. Try: Rim Dinger section at Bike Park Wales, Pugsleys Bottom and Lurch on the Dragons Back at Coed y Brenin.
Rock music: What you should totally be listening to, man.
Rock roll: Another ‘let’s stick a giant rock in the trail’ feature, but this one is essentially a slanted rock like a short slide that you roll down. No steep drops or genuine difficulty. Try: Cwm Rhaeadr.
Singletrack: As fun as riding fireroads and broad tracks is, the real interest is in riding narrower paths through the middle of nowhere. Basically singletrack is anywhere where you have to ride single file (although there is a technical definition of exactly how narrow a trail has to be to be singletrack, which I can’t remember and isn’t terribly important). Singletrack sections are usually the fun and interesting bits that you’re aiming for really, and represent the payoff from the fireroad and road riding that gets you there. Try: everywhere! Twrch and Cafall for trail centre stuff, Cwm Rhaeadr for a blast, Doethie valley for natural stuff.
Snakebite: Either an impact puncture (typified by two punctures – one on either side of the tyre) or a beverage consisting of half lager and half cider, which is good for students trying to get drunk cheaply, and for other people who don’t like their alcohol to be remotely palatable.
Sprocket: Generally, a cog with scooped teeth to take a chain. Specifically on a bike it refers to the sprockets mounted on the rear hub, generally in a set called the cassette. These are the fine tuning gears, and what you’ll switch between most often.
Technical climb: Section of uphill cycling that requires more skill than most. Rocky, steep, slippery climbing that means you need to carefully pick a line, and possibly stand up on the pedals. Range from a minor challenge that’s quite satisfying to find you’re able to ride, to sections that you can’t imagine how people ride. Try: Twrch at Cwmcarn, the Dragons Back at Coed y Brenin.
Toeclips: Largely outmoded middle ground between flats and clipless pedals. Plastic things that hold your feet to the pedals with straps. Possibly worth riding with for a while to work out whether you want to ride on flats or clipless pedals, but otherwise largely worth avoiding. One or other of the alternatives is generally better.
Uplift: A service that means you don’t have to do the climbing bit of mountain biking. Usually a minibus with a bike trailer, although some places are experimenting with ski lifts in summer.