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.
Step 1: Find Something to 'push' the Slime Through
I used the tip of this pen in order to push slime through the small hole we are about to make in the tube.... you can use anything though, just remember that the slime clots if the hole is too small (it guarantees to self-seal any hole 3mm or smaller in the tube), making it impossible to push any more through, so you need a balance between the ease of patching the hole and having it big enough to actually get the slime in there.
Step 2: Put Your 'funnel' on to the End of the Provided Slime Tube
I used standard sticky tape (cellotape) which was lying around the house to provide a better seal.
Step 3: Puncture the Tube!
Step 4: Squirt in the Slime
Step 5: Clean and Dry the Tube
Step 6: Prepare for Patching
Then apply the vulcanising glue over an area which is approximately the same size & shape as the patch you are going to use.
Let the glue dry (i.e doesn't feel 'tacky' to the touch)
Step 7: Apply the Patch
Peel off the plastic, and there you have a patched self healing tyre. Make sure that when you are peeling the plastic off the patch that you peel it from the middle of the patch to the edge of the patch - otherwise the edges could stretch up off the tube and affect the quality of the seal.
Now put the tube back in the tyre, the tyre back on the wheel, and make sure that you rotate the wheel straight after inflating it to distribute the slime evenly - it will also seal any small holes that may have triggered this slime-ing tyre surgery in the first place ;)