Martin Watson
Ayr, UK
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There are two main ways that a bike tyre can be ruptured – by a penetrating object or by a “pinch” puncture.
A penetrating puncture from, say, a thorn is more likely at high speed – and also at high tyre pressure, as the tyre has less opportunity to deform away from the object rather than being ruptured. A pinch puncture occurs when the bike’s inner tube is compressed between a hard object, such as a pothole edge or rock, and the tyre rim. This is more likely at high speed and at a lower tyre pressure. So, to avoid a puncture, it is best to ride slowly.
Rodney Priest
Chippenham, Wiltshire, UK
Punctures on rough surfaces are best avoided by pumping tyres up hard and standing on the pedals through the worst sections.
Lower speed is only relevant for helping you see an object ahead in time to avoid it and lift your bottom off the saddle. This allows your calf muscles to act as shock absorbers and so help prevent punctures that happen when the downward force of body weight is transferred through the frame to the metal rims and sharp object, thereby pinching the rubber tube between them.
“After I taught students the ‘bum-off-saddle’ technique for cycling over rough ground, they didn’t get a single puncture”
For five years, I took groups of inexperienced teenage cyclists out to ride along stretches of sharp aggregate that was used to pave a tar-free track on the edge of Salisbury Plain. After learning the “bum-off-saddle” technique, they didn’t get a single puncture.
Anthony Woodward Portland, Oregon, US
A sharp object, such as a nail or thorn, will penetrate the tyre and tube at whatever speed the bike is ridden. Pinch punctures – also known as snake bite punctures because the holes resemble snake bites – occur when the tyre forcibly hits an obstruction. The impact will be more forceful the greater the kinetic energy – that is, the greater the speed – of the bike.
Riding slowly over rocky terrain will therefore reduce the chance of a pinch puncture.
Peter Groom
Winscombe, Somerset, UK
The speed at which you choose to cycle is mainly about your skill at balancing, control, safety and bragging rights. As your abilities develop, you can go faster with more control and be easier on the bike overall, choosing a better line and using the suspension to reduce impact force against obstacles. Going faster reduces contact time with the trail surface, so possibly could reduce penetration by thorns, but not by much.
I went from getting punctures every time I rode to none at all not by changing speed, but by switching to tyres without inner tubes, where latex fluid sloshes around in the tyres and fills any holes.
Anyway, with the Mendip hills on my doorstep and a mountain bike in the garage, it is time for me to stop writing emails and get out!
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