Plugging the Hole - Stan's Notubes Sealant

I've received a few visits from the puncture fairy of late, it would seem that the soft compound of the new Schwalbe CX Comps that I have fitted to 2 of my bikes are less puncture resistant than other tyres I have tried in Schwalbe's "active-line".  Not wanting to move away to a heavier more puncture resistant tyre I took a look at the options available to reduce the risk of punctures.  It was while watching the "Cycle Show" on ITV4 that there was mention of pro-cyclists using liquid tyre sealant to good effect, the particular sealant being referred appeared to be made by "Stan's Notubes" the U.S manufacturer of tubeless bike tyre systems.  Unlike other tire sealants, Stan's Tire Sealant is a very thin, low viscosity liquid that coats the inside of the tire and carries with it specially formulated sealing crystals. The sealant adds only around 50 grammes per tube; this is an extremely attractive proposition when compared to the difference in weight of highly puncture resistance tyres like the Schwalbe Marathon Plus which weighs in at 415 grammes heavier per tyre than the CX Comp in 700cx35 size.

The sealant works by remaining liquid in the tyre during normal use and then when a puncture occurs a small amount of the sealant is forced by the pressure within the tyre into the puncture where it solidifies forming a permanent latex "plug".  One application of the sealant is able to provide protection against multiple punctures of up to 1/4".

A quart bottle of sealant can be bought for around £20.00 which is sufficient to treat 16 tyres making it extremely cost effective.  Again, by comparison again the Schwalbe Marathon Plus costs around £15 more per tyre than the CX Comp in 700cx35 size.
All you need to puncture proof your tubes!
The sealant is a dispensed into the inner-tube through the valve having first removed the valve core.  Schrader valve cores are easiliy removed with a core removal tool.  Only certain manufacturers of presta valve inner-tubes fit removable cores, Schwalbe do, and the cores can easily be unscrewed and refitted with the aid of a small pair of pliers.
Schwalbe Presta Valve with Core Removed
Although you can buy a purpose made sealant injector to apply the sealant to the tube I found that a plastic syringe as you would use to refill inkjet cartridges worked perfectly.  The sealant is non-toxic, odourless and water soluble and is exceptionally easy to apply taking around 5 minutes per tube.
Applying the sealant with a syringe.
The life of the sealant when applied is quoted as being between 2 and 7 months depending on the thickness of the tyre and ambient temperature.  These figures appear to be in relation to using the sealant in a tubeless tyre, so I would expect to achieve a longer working life when used in a good quality inner-tube and tyre combination.  More sealant can be added after the original application ceases to be effective and given the relatively low weight penalty there is no reason that the life of the inner tube could be extended to 2 years or more.

Well that's the theory anyway!  I look forward to providing a long term test report in due course.

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