Puncturesafe

I've used Slime on commuters and training bikes for years, and have it in my motorbike tyres. Makes no difference whatsoever to ride and handling and works.

People talk a lot of total cack about it; it's good and works. If you have it in road tyres, you will get a bit of pressure drop - 20-30 lbs or so if you are starting at 100psi or more before it stops the leak, but you can live with that, and pump it up again.

This.