I have now run my Carrera Vengeance for two years/4000 miles successfully without a puncture using the puncture proofing "slime". The manufacturers recommend replacing the slime after two years. However, I am wondering if it is okay simply to top what's already in the tubes or if the tubes should be replaced also at this time. Any thoughts, please?
There have been several people here on Pedelec, over the last few years, who have experienced problems with some form of slime, blocking valves. Which is why I would never use it myself, as to me that will be a likely problem area for at least some.
What I have used for some years now, with complete success, is to cut the tread (remove sidewalls) off a worn tyre, I do it when replacing with new, and place the old tread between the new tyre and the tube (usually also new), effectively making the tyre tread a lot thicker, making it far more difficult for thorns and suchlike to penetrate to the tube.
I am sure that I occasionally pick up thorns still, but no punctures!
Further more, as armoured tubes and tyres have got a lot cheaper (IMHO) here in Germany, over the last couple of years, I now run with them AS WELL!
I could not tell you when I last had a puncture exactly, but well before 2016.....
This fix costs just a little of my time, but no money, and has worked 100% since I started using this method.
No messy slime to play with or problems with valves getting gummed up either.
Apparently its an old trick, that a cycling colleague told me about, one that I myself had never heard of till then.
I have mentioned it to others here, ALL OF WHOM already knew about it!!! I must be the very last to know about it in my area......
regards
Andy