Tubes - Specialized Air Lock - opinions please

Hi.
A few weeks ago I bought some for my training bike. They weight - well it must be over 200 grams. Pretty slow to ride with but I thought they'd see me through winter with 1.2mm tube thickness and the gunk inside that is supposed to seal up flats.
Yesterday I had my first flat with them. The gunk didn't seal it(left it a day and still not sealed).
The valve won't close properly now either so it's not even any good as a normal(but very heavy) tube.

Anyone else had experiences with them?

Happy riding, Paul

I don't bother with that type of tube. I invest my puncture prevention efforts in the tire. These days there are some pretty puncture resistant tires out there that don't have that much weight penalty and ride nicely too.

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I agree - I usually have Michelin Megiums as training tyres - puncture resistant and last well(I got 8500 kms out of a back one!!) but I hate having to change tubes at the side of the road in the dark when it's raining as well