Nobeer – in our damp west coast environment, how often do you top up the sealant, and by how much each time ?
All depends. When I used to use spesh tyres, mibbe 4 months at a time, as the liquid (water) from the stans seems to leech through the sidewalls.
Now using a mixture of Mary’s and WTB tyres, they are far better in the sidewall so the stans stays the way it should. Frinstance, fitted a MM to the Capra last June, haven’t had to top up at all. That Mary isn’t far off being past it’s best, so I’ll be changing it shortly, the gloop has lasted the life of the tyre (It’s a suoergravity vertstar, so very soft and wears pretty quickly, but it’s a tradeoff I take for the grip it gives).
New stans race stuff can’t be fired in through the presta, so I pop a bead off, mibbe 10 inches, it’s still easy enough and can be re-inflated with the track pump.
Edit – Iain, I generally use 2 of the red capfulls on a new tyre.