I have two bikes - one is a mountain bike running Sun Rhynolite rims, with presta valves (26" wheels), the other is a flat bar roadie running 28mm 700c tyres. I have had 10 punctures across both the bikes in the 3 months I have been living in town, despite running 'Mr Tuffy's' tyre liners and heavy duty tubes.
I am told that there are only two effective ways to save my sanity by reducing the number of punctures I get - one involves spending $120 on a set of tyres, the other is putting slime in the tubes. Problem with slime is that you can't push it in through a presta valve and tubes with presta valves with removable cores are rare in 28mm or 26" x 2.125 versions.
So I decided to go old school. In this instructable I will show you how to make your current presta valve tubes into self sealing slime tubes with a little bit of surgery.
PS - slime in your tyres will add a noticable amount to the rolling weight of your bike, so it takes some getting used to, but it's worth it in order to prevent those annoying punctures.