Schwalbe Doc Blue Tubeless Sealant

The Schwalbe Doc Blue Professional tubeless sealant offers pretty decent protection against ending up with a fully flat tyre when out on the road, sealing against small intrusions quickly. You need to watch the tyre pressures if the hole is quite big, though.

• Pros: Easy to use applicator; seals the majority of punctures quickly
• Cons: Pricey; not so good on bigger cuts at high pressure

The popularity of tubeless setups is increasing, with many riders making the switch from a tyre and inner tube combination, but to make this all work you need a decent sealant for when the worst does happen.

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Doc Blue comes in at £7.99 for a 60ml bottle, which isn't cheap, but that'll sort both the front and rear when it comes to road tyres. (It's available in a bigger 500ml bottle too, for £20.99.)

Setting everything up is simple, with a valve core removal tool in the box. Unscrew the head from the valve and poke the top of the bottle into the hole to decant the sealant – job done.

Schwalbe says that the Doc Blue will remain a liquid for between two and seven months depending on conditions, and while I've only had it in the tyres for around five weeks it has been hot down here in the south west for quite a while – mid-20s for the majority of the time, with a few days nudging the 30s.

Taking the tyres off for an inspection before writing the review saw the consistency of the sealant as thin and runny as it was when it went in, so it isn't going to need replacing anytime soon. (Schwalbe says it's also reusable.) I'll keep an eye on that and let you know if I have any concerns.

I run my tyres at quite high pressures on the road, and the majority of foreign bodies trying to enter through the rubber or sidewalls get shrugged off. That's the main reason why I don't run any of my own bikes tubeless, and I wasn't exactly surprised to get through the test period without a single issue.

> How to avoid a puncture

Taking things into my own hands, I stabbed the 28mm tyres with a drawing pin and the sealant dealt with the puncture quickly, losing only about 15psi from the original 90psi.

I left it for a few hours and pumped the tyre back up with no issues.

Making a larger hole – well, more of a slice with a scalpel blade (about 3mm long and the width of two scalpel blades) – saw a bit more of a skirmish from the Doc Blue to stem the flow of escaping air, but again it did the job, dropping to around 40psi.

With this larger tear, if I pumped the tyre up above 60psi the sealant would hold for a while before blowing out of the hole and having to reseal it again.

It was always at the 60psi range, so now that I know, I'd continue to ride without inflating the tyre above that and then fix it with a patch or plug at home before re-inflating to my desired pressure.

> What they don't tell you about going tubeless

So, it works on the size of the holes you are likely to encounter on the road but it isn't the ultimate fix for everything. To be fair, Schwalbe does warn that it's 'Not effective on large defects (cuts/bursts)', so maybe I was being a little over optimistic.

When it comes to value, the Doc Blue does look a little pricey. The Muc-Off No Puncture Hassle sealant kit has an rrp of £9.99 for 140ml. Or you could go for Orange Seal Endurance sealant, £7.99 for a 4oz (116ml) bottle (or £14.99 for a 237ml bottle – enough for nearly eight tyres).

Up the bottle size and you get more Doc Blue for your money, 500ml for £20.99, but the same applies to the other brands, so it's still not the best value in comparison.

Overall, the Schwalbe does a decent job of keeping you rolling, but it's pricey against the opposition.

Verdict

Seals the majority of punctures but it's quite an expensive way to do it