Latex inner tubes

This isn’t about small-wheeled bikes, as no-one makes off-the-shelf latex tubes for them.

The wired-on (or HP, or clincher, if you must speak USanian) tyre has been the most popular option on bikes for many decades, due to the relative ease of fitting and puncture repair. Previously, tubular (or sew-up) tyres were very popular, but now only really exist for track use and for top-end road racing.

The new kid on the block is tubeless tyres, which are very much like car tyres; there is no inner tube and they form their own airtight seal to the rim. Claimed advantages of tubeless tyres include lower rolling resistance, as there is no friction between an inner tube and the tyre, and the ability to run at lower pressures without pinch punctures. Another claimed “advantage” is an ability to seal punctures, but that is really a function of the slime that is used in them to seal any small leaks, whether from foreign objects or just from poor sealing against the rim. Tyres with tubes can use sealant too.

Tubulars maintain a niche because they can be run at sky-high pressures of over 200psi on a smooth track, where rolling resistance is lowest with a vary hard tyre. They can also be ridden when flat, which is an advantage in a road race, while waiting for the service car to catch up with a new wheel.

Nevertheless, the lowest rolling resistance on a normal road is provided by a high quality wired-on tyre with a latex tube. A latex tube:

• runs more freely because it is thinner and more flexible than butyl rubber
• is more resistant to some types of puncture because of its flexibility
• is far lighter than butyl
• takes patched repairs extremely well, because they tend to be seamless and rubber cement sticks best to latex

You don’t get owt for nowt, though, and the reasons not everyone uses them are:

• They need topping up with air every day that you ride
• They cost 2-3 times as much as butyl tubes
• They need to be more accurately sized to the tyre width
• When they puncture, they are reputed to deflate very fast

I like latex tubes. They would be a pain on a bike that is ridden daily, and even on a very long ride you have to expect some loss of pressure; I started the 113-mile Dunwich Dynamo with 160psi in both tyres (700 x 23), so there would still be enough pressure to prevent pinch punctures 8 hours later. For a bike that is ridden intermittently, they are one of the few cheap upgrades that gives a readily noticeable boost in speed. The power saving is estimated to be 5W per wheel at a decent riding pace. You can feel the difference and, oddly, hear it; a tyre with latex tubes makes a distinctive swishing noise.

I’ve only had one puncture on latex tubes, so I can’t really confirm the “rapid deflation” thing. The puncture I had was from a shard of glass that also ripped out an inch of tyre sidewall, so any tube would have gone off with a bang.

Vittoria and Michelin make latex tubes in pink or green respectively-take your pick. Check the size is within spec for your tyre; it is common for latex tubes to be suitable for, say, 22-23mm tyres whereas a similar butyl tube will fit a wider range of 23-28mm (and can be used in an even bigger tyre, if needed to get you home).

Latex should not be exposed to direct sunlight, as this rapidly weakens it, something you may have seen if hanging up toy balloons outside; they burst within minutes in strong sun.

Most latex tubes are made for 700c racing tyres but those for cyclo-cross bikes will also fit touring tyres. For small-wheeled bikes, it is possible to “roll your own” from larger tubes, by cutting and splicing them. At least one firm does this commercially to make Moulton tubes. You could try it yourself using rubber cement and an overlapped section.