Punctures in the wet
7th June 2018

Anna
van der Breggen, by youkeys,
Licence
CC BY 2.0
I set out for a long ride on Sunday, after overnight rain. The
roads were wet in places, with sand and stones washed onto the
tarmac. Some puddles were unavoidable because they stretched from
one verge to the other.
The first soft, sinking feeling came only 6 miles in. I hoped that
I was mistaken - perhaps there was just something in the surface of
the lane that mimicked the ride of a low-pressure tyre? But no, it
was a puncture. At least it's the front, I thought.
I opened my saddle bag, and was surprised to find I had no spare
inner tube there. I always have one. Well, obviously not. Anyway,
wheel off, tyre off, inner tube out, puncture located. I found the
offending object - a sharp bit of stone or glass lodged in the tyre
- and removed it. I patched the tube (Park Tools patch), put it
back, and pumped the tyre up with my surprisingly good Topeak
Pocket Rocket pump. I used to have a shocking mini-pump that
essentially didn't work (disclaimer: it might have been me using it
wrong), but this one is great.
I set off again, but now with doubts about the wisdom of riding a
long way from home. The potholed road by the river Ure between Wath
and West Tanfield seemed a bit 'sus'. I stopped at West Tanfield to
commune with donkeys, and when I was about to pedal off, I noticed
that the back tyre was soft.

Donkeys at West Tanfield
I got my hands good and dirty this time, and did a bad job into the
bargain, resulting in a stop 5 minutes later to peel off the first
patch, and apply another.
The roads began to dry, and for the rest of the ride, I was the
un-deflated champion of the country lanes of North Yorkshire.
This got me thinking about why punctures are more likely in wet
conditions. I'm not a pioneer in the field - it's a subject that is
covered on the web - so here is a little summary.
Punctures in the wet: why are they more common?
British
Cycling says, 'It is no coincidence that punctures are more
common in wet weather. More grit and debris is washed onto the
roads, and the water acts as a lubricant for objects penetrating
your tyres.' The wisdom of the bike
radar forum is that debris sticks to a wet tyre, and is
therefore more likely to work its way through.
Punctures in the wet: how can you prevent them?
It's recommended to drop your tyre pressure by 5-15 psi in the wet,
for better grip. British Cycling suggest that should help avoid
punctures from sharp flints. Don't drop too low, though, as you'll
run more risk of a pinch flat or a thorn puncture.
Other than tyre pressure, puncture prevention is down to equipment.
You can buy tyres that have a layer of Kevlar in the rubber, which
helps stop sharp objects penetrating the tyre. You can also buy tyre
liners, which go between tyre and inner tube, to provide puncture
resistance.
There are 'self-healing' inner tubes, which have slime inside: if
you get a puncture, some slime comes out of the hole and solidifies,
instantly sealing the hole. They are heavier than normal inner
tubes, and in the comments to a road.cc
review, some users complain that the valves get clogged up
with slime, and when the tube punctures, the gunge goes everywhere.
On the other hand, KiwiMike from north Hampshire, where there are
lots of thorns and flint shards, said that his cycling club is
making them compulsory for 100 mile + runs.