Tag Archives: tubes

Flat tyres are irritating – Part 2

The Leadout

This is the second part of a two part blogfest on flat tyres. The first part focused on the types of flats and this the second parts explains what you might be able to do avoid them.

The Breakaway

You have two basic choices, change the way you ride or pony up for some new kit for your bike.

The Peloton

The cheaper choice – change the way you ride

Tactic Description
Road positioning This is often caused by poor road position: people often get an unusual number of flats because they are riding in or close to road gutter. The main travel lanes of most roads are kept fairly clear of glass and other dangerous debris by passing motor traffic. Cyclists who travel in the normal traffic areas of the roadway benefit from this. It also improves your visibility to motorists and provides greater room to move around obstacles.
Pressure Tire pressure is the hardness to which a tire is inflated. This is commonly measured in PSI – pounds per square inch. The “correct” inflation pressure is determined by the weight load, the tire width, and, to some extent, the riding surface. Getting it right can play a major role in puncture prevention. Too low and you may pinch the inner tube if you hit a pothole. Too high and you increase the risk of penetration punctures. Around 100psi is a good starting point for most road bike cyclists but consult the recommended pressure printed on your tyre. Less well known is the downside of over-inflation; this causes a harsh ride and can also cause poor traction on bumpy surfaces as over-inflated tires tend to bounce, breaking traction on the road surface.
Stop and check the tyre The pent-up air in your tubes wants desperately to join its friends in the atmosphere. If you ride over sharp objects, immediately sweep your tire with a gloved hand to remove debris.

The more expensive option – buy some new kit

Tactic Description
Tubeless tyres If The tubeless tyre you have a need for speed but still want to reduce your vulnerability to punctures, tubeless clincher tyres may be worth a look. With no inner tube within the tyre casing, pinch flat punctures should be a thing of the past and they roll quickly at lower air pressures so the risk of penetration punctures should also be lessened. They also work very effectively with liquid sealants; a small amount in each tyre should seal up any punctures in the tread area before too much air pressure is lost.
Thornproof tubes Special “thornproof” inner tubes protect against thorns and glass shards. These tubes are very thick on their outer circumference, so that a short thorn or a small glass shard may be embedded in the tube without being able to reach in far enough to let the air out. The outer wall of the tube is about five times as thick as a standard issue tube (see the cross section on the right) and this reduces the risk of penetration. They also weigh around 150g more than a standard issue tube—that’s 300g of additional rotating mass on your bike.
Tire Liners Tyre liners are made from robust but flexible nylon and fit between the tyre casing and the inner tube eg Mr Tuffy. They add weight and stunt tyre performance but will dramatically reduce the chance of penetration punctures. Just ensure that the liners are fitted properly with no angled edges where they are cut to size—poorly fitted liners can actually cause punctures.
Kevlar re-inforced tyres Kevlar-belted tires have a layer of kevlar under the tread surface, with the purpose of making the tire more resistant to punctures caused by small sharp objects, such as thorns and glass slivers. Kevlar-belted tires have slightly higher rolling resistance, price and weight than corresponding tires without the belt. Advantage of being fold-able and therefore transportable on long rides.