One of the best solutions — pardon the pun — to the puncture problem is this liquid sealant from South Africa, called Sludge.
The manufacturer claims it’s the number one tyre sealant for all types of tyres on the African continent.
Uniquely, Sludge can be used to protect inner tubes that don’t have a removable valve core. Normally, any latex solution can be used only when the valve core has been removed from the tube — but most bog-standard tubes don’t have removable cores.
To use Sludge, simply undo the valve, snip a section off the spout of the applicator bottle (just enough to allow the spout to be screwed on to the thread of the valve stem — the valve cuts a thread into the soft plastic). Once attached, allow 50-60ml of liquid into the tube before removing the bottle. Sludge recommends adding a little Vaseline to the valve after application, but we didn’t bother because we did this ‘in the ﬁeld’, as it were.
Then inﬂate the tyre and give it a spin to distribute the ﬂuid evenly throughout the tube, thus sealing your ﬂat and creating puncture-proof inner tubes.
Of course, you can buy pre-ﬁlled tubes from ﬁrms such as Slime, but where Sludge has an advantage — especially for weight-conscious cross-country racers, lightweight commuters or roadies in training — is that it allows you to puncture-proof super-light tubes, instead of having to use the standard ones Slime offers.