Thanks all. 25's it will be then. There is plenty of frame clearance, it has 28's on at the moment. I bought a new back wheel during the week and it is a narrow road bike wheel, but the front wheel is the 16 - 622. I will order a pair of tyres after Christmas. Eventually I will also get a new wheel to match the new back one! It is for my Peugeot roadbike by the way.