Even those of us who are fully on-board with tubeless, who regularly refresh our sealant, and keep a tire plug repair solution in our everyday ride kit, will eventually get into the literally sticky situation of needing to stick a tube into a flat tire to get home. For me, this happened when I struck a railroad track at a weird angle, causing my rear tire to unseat and lose all air pressure in about 2 seconds as I skidded to a halt. My two CO2 canisters were not enough to re-seat the tire, meaning that the only way to inflate it was to use the tube that I had in my repair kit.

Situations like this are why milKit – a tubeless sealant brand – is now offering TPU tubes that pack down to a minuscule volume, yet promise twice the puncture resistance of normal butyl rubber tubes.

Let’s look at how that works…

A Better Chance of Avoiding Punctures It turns out that for 700c and 29″, two sizes of tube will work for 99% of the tires out there (Photos/milKit)

Regarding their claims on puncture resistance, milKit testing shows that the TPU tubes can withstand 32Nm of force before being penetrated by common sharp objects like glass shards, thorns, or jagged stones. Standard butyl tubes, on the other hand, are far less flexible than the TPU material milKit uses, and can be pierced by those same sharp objects at just 15Nm. Presumably, a similar increase in flat resistance would apply to pinch flats too, right?

Generally speaking, the reinforcement & overall durability of your tire casing is more of a determining factor in whether you get a puncture riding over a specific object or not. But especially if you are riding a lighter casing tire, you’ll have a much better chance of getting away unscathed with the milKit TPU tube inside your tire vs. traditional butyl.

MilKit wanted to keep it simple with their new blue TPU tube offering, as they do talk about these mostly as a backup solution to “get riders back on track fast” when their tubeless system breaks down.

The size range is simple – one for both road and gravel, and the second for MTB. I feel like this level of tube spec simplicity, or close to it, was possible all along, even before tubeless took hold. But it’s even more common with the stretchiness of TPU. (But remember, once you inflate a TPU tube into a certain tire size/width, you can never use it for a smaller tire afterwards.)

milKit TPU tubes – Pricing, options & availability

The milKit TPU tube for road and gravel works with 700c tires from 28-45mm, and features a 60mm long Presta valve. The road/gravel TPU tubes weigh a claimed 55g each.

The milKit TPU tube for MTB works for both 27.5″ & 29″ tires and tire volumes from 50-64mm / 2.0-2.5″ wide, with a 42mm Presta valve. The mountain bike TPU tubes weigh in at just 76g.

MilKit produces all TPU tubes in the EU. They are fully recyclable, and sell for the same $33 / 30€ no matter the size. Get them now directly from milKit or through their regular retailer partners.

milKit.bike