MilKit Road & Gravel Tubeless Sealant

The new milKit Road and Gravel sealant is a great choice for those of us who like to run higher pressures. It seals holes and cuts quickly in a range of tyres, and is well priced too.

As the name suggests milKit's Road & Gravel Sealant is designed to work across a range of tyre sizes, and more importantly, a range of pressures.

A lot of tubeless sealants work okay with road tyres, but just can't keep cuts closed about 50psi or so. This means you'll lose a lot of pressure as the air escapes to start with, and if you try to pump it up the hole will just reopen once you get above 50psi. That's enough to get you home, of course, but ideally you'd be able to ride on at your chosen pressure.

Like many other brands, milKit keeps the exact nature of its ingredients secret, but this mix is designed to work properly at the higher pressures found in road tyres. In fact, most of the ingredients it does mention are not in here at all; it's a synthetic latex and avoids ammonia or anything else chemically aggressive.

After two months with it in my tyres, I still hadn't picked up a puncture in the natural way, so I had to bring out the drawing pin and the scalpel to make small holes and slits; the type you pick up from thorns, sharp stones and small fragments of glass.

The milKit works really well, sealing my 28mm road tyre quickly and dropping only 10psi from the 85psi I started with when punctured with the pin. On larger cuts and holes the performance is good too. On 5mm long by 1mm wide slits from the knife it sealed quickly, and larger holes up to about 2mm in diameter were dealt with impressively too.

Anything bigger than that it would take a little longer to seal, and I'd say it could cope with anything up to 3mm in diameter, realistically.

On a 40mm gravel tyre it could cope with slightly bigger holes (around 4mm,) due to the lower pressures allowing it to set easier. Anything above these sizes I'd recommend using a tyre bung anyway.

Its consistency means that it can be applied through your valves, which means you don't have to wrestle one side of your tyre of the rim. Ideal if you need to top it up mid-ride. You don't even need to shake the bottle.

milKit says this will last up to five years in the bottle, even when it's been opened. That's a lot longer than our test, though... as you might hope, it has not degraded even slightly yet. Over the two-month review period the sealant has seen conditions ranging from around 10°C to just over 30°C, and when taking the tyre off to switch wheels it still looked and felt just as liquid as on day one. The recommended working temperature range is -20°C to 50°C.

It's obviously early days though, so if it dries out prematurely, I'll be back to update the review.

Value

At £24.78 for the 500ml container (75ml, 250ml and 1L bottles are also available), the value is good. The Challenge Smart Tubeless Sealant I recently reviewed works out at £30 per 500ml, while the Pirelli Cinturato Sealant is much more expensive at £40 per 500ml while giving the same results.

Overall

This is a good choice if you are running high pressure tyres on either road or gravel bikes, it works quickly and it's reasonably priced. It's very good stuff.

Verdict

Works with higher pressures and offers good life expectancy regardless of conditions