Cyclescheme How to: Prevent punctures

Cyclescheme, 10.02.2015

Cyclescheme How to: Prevent punctures

A flat tyre is the last thing you want on the way to work. Here's what you can do to avoid it.

It's 8:45am, it's drizzling with rain, and you can feel your bike's rear tyre deflating. How unlucky is that?! Not as much as you'd think. Punctures don't strike randomly. Every cyclist will get one sooner or later, but there's plenty that you can do to make sure it does happen later. Take these preventative measures and you might never be let down by your tyres.

Pump up the volume

Firmer, higher pressure tyres puncture less often. A tyre at, say, 80psi has half as much rubber in contact with the road as a tyre at 40psi, so it's less likely to encounter shards of glass or flint in the first place. When it does so, the glass/flint/whatever is less likely to press into (and be picked up by) the tread of a firm tyre than a soft tyre. Firm tyres are also much less likely to suffer snakebite punctures, where a bump flattens the innertube against the wheel rim so that it gets nipped between rim and road.

Tyres have a pressure rating stamped on the side. Make sure your tyres are inflated to at least the minimum figure; they lose air over time, deflating like party balloons. Invest in a track pump (i.e. a floor pump) with a pressure gauge. This takes the guesswork out of tyre pressure checking and makings pumping much easier. Expect to spend €30 - €70. Check skinny tyres every few days, medium width tyres every week, and fat tyres every couple of weeks.

Check for sharps

Some punctures are instant. A thorn or shard of glass impales or slashes the tyre and it deflates immediately. Some punctures are gradual. A crumb of glass or sharp grit becomes embedded in the tyre and gets slowly forced through as you ride, causing a puncture hours or days later.

If you know you've just ridden through glass or if you can see or hear that one tyre has picked up a bit of grit, pull off the road, dismount, spin the wheel slowly, and then (taking appropriate care) brush it off. When you check your bike's tyre pressures at home, have a quick look for sharps too. Carefully dig out any that you find with a penknife.

Ride where the debris isn't

Stay out of the gutter. Debris gets swept to the edge of the road by the repeated passage of car tyres. The gutter is where bits of glass end up.

Some routes accumulate glass. That cycle track may not be swept. That backstreet may have bottles regularly smashed on it. That difficult junction may have fender-benders. Avoid these places unless you have confidence in your tyres.

Some routes are risky only at certain times of year. Rural roads that have their hawthorn hedges threshed are a puncture minefield. Avoid them – or ride through carefully or dismount if you can't.

Fit tougher tyres

Not solid tyres – they're awful. You want tyres with a protective layer under the tread. This may be a synthetic fibre such kevlar or a different consistency of rubber. The toughest tyres use a thick layer of springy rubber and have the word 'Plus' in their name: Schwalbe Marathon Plus, Continental Touring Plus, and Panaracer Tourguard Plus, for example. They're harder to fit, heavier, and often slower, but if puncture protection is your top priority, these are what you need. 

If you want lighter weight, faster tyres, you will need to compromise on puncture resistance. But even for a road bike, it's wiser to use tougher 'training' or 'four season' tyres for commuting rather than race tyres.

Use tyre sealant

Tyre sealant such as Slime is synthetic goo that you put inside your bike's innertubes. You can buy innertubes ready filled with sealant, which is less messy. Either way, it's clever stuff. When you get a puncture, the escaping air forces the sealant into the hole, where it hardens into a plug, fixing your puncture automatically. It only works on small holes, not cuts or tears, and you will lose a little pressure each time. The tyre might need topping up with air – break out your portable pump – or you may be able to continue, unaware that you've 'punctured'.

Note that there are two other types of sealant:

  1. Sealant spray is sealant-plus-compressed-air in a can; you use it to re-inflate and fix untreated tyres.
  2. Tubeless tyre sealant is for bikes without innertubes, such as some expensive mountain bikes.


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