Buyers guide to buying a tire for off-road bikes. Advice on terrain, rain, road and cleaning.
Mountain bikes, in general are heavy. If you can afford a very expensive, state of the art mountain bike, you might want the more expensive lighter weight tires. The reasoning for this is that the spinning weight of the wheel, adds more actual weight to the bike. It's because of centrifugal force. Anything spinning carries more actual weight the faster it spins. So, the heavier the tire, the more it will weigh as it spins and in return, will affect the amount of effort to keep it spinning. In short, it's harder to pedal up-hill or on a flat surface with a heavier tire. You can cut down in weight by buying Kevlar beaded tires, tubular tires, and tires with thin, less protected sidewalls. The disadvantage is cost, higher risk of flats and tire damage. This type of tire, appeals to the racer, who is willing to take risks.
Slick tires for mountain bikes have no knobs; they may come with grooves to displace water as it rolls on wet terrain. If you plan using your bike to ride on a paved surface or a hard compact surface such as rock, then slick tires are best. Knobs on the tire will give it a higher roll resistance, causing more friction, thus slowing you down. There are brands that will have both. They have a smooth surface on the face of the tire with knobs on each side. This is for cornering, where you want to grip the surface in the turn and keep the tire from skidding. Another factor of slick tires is they will take higher air pressure, which gives the tire less rolling resistance.
Knobby tires, like tractor tires, are made for dirt. You can ride a knobby tire on a hard surface, but because of the knobs, the bike will be harder to pedal. There are many different brands available. Each claims a certain advantage but the point to them all is that the roughness of the tire, its knobs, allows the tire to sink into the medium, thus gripping it and causing greater traction. The more knobs, the better the grip. The width of the tire plays into this as well. If the soil you're riding in is sandy, the wider the width the better.
Another important factor is air pressure. If your tire is inflated to the maximum, with little give to the tire, you can ride faster but you run the risk of pinching the tube when you hit a hard object. You can get better traction with a lower air pressure. It allows more tire surface to contact the terrain, but you go slower because of the increased area of contact. It can also cause damage to the rim if your wheel if the pressure is too low. Carry a pump of some kind with you. If you have a long climb ahead of you, inflate your tires. If you have a long decent, deflate your tires a little. Remember not to go over or under the recommended amount of air pressure, listed on the sidewall of your tire.
For most people, they want something that will give them trouble free service without having to buy several different tires. Look for tires that have good sidewall protection. Some tires are labeled as being "˜sticky'. The tire's casing is made of material that stays softer than most mountain bike tires. It doesn't stick, it just flattens out more at the point of contact because of what the tire is made from, giving you better traction with less weight. They also wear out faster because of the softer material that goes into their making. You can put on your front wheel, a lighter tire and on the back wheel, where it takes a beating, a heavier, wider tire. They make sets of tires for mountain bikes with this in mind. They have smaller knobs on the front tire and larger ones on a wider back tire. When you mount a set like this, make sure you have them on the correct wheels. Some manufactures recommend that the tire be mounted in the correct direction for maximum performance. They will have an arrow pointing in the direction your bike would go if moving forward. If you are unsure and your tire has no arrows, the rule is that the manufactures name and where the size of the tire is located, be mounted so that this information is read on the gear side of your bike, the right side.
Remember to clean your tires after riding, a garden hose spray works well for this and all the parts of your bike are sealed, it's why you can play in the mud with them. Dirt, rocks, sticks""I have found house keys lodged in-between the knobs""can impair the effect of your knobby tires and add a great deal of weight to the bike on your next ride. While you're cleaning the tires and bike, check the sidewalls and condition of your tires. They take quite a beating and sharp rocks can tear the fabric of your tires easily. Remember, you will not have the advantage of roadside assistance when riding in the backcountry. Bring with you, spare tubes, pump and patches. Always tell someone responsible where you're going and when you should return. Bring plenty of water, a snack and enjoy a wonderful sport.
