First of all thanks everybody for the encouraging replies to the discussion. Coming days I will try to tell a little bit more about our trip.
For the last 5 years we, that is my wife Monique and me, spend our holidays cycling. In summer we stay in Europe but every winter we go to warmer climates. We have cycled in Thailand, Malysia, Vietnam, Laos, Cambodja, Mexico, USA and already once in India. That was three years ago and we started in Chennai and cycled via Pondicherry, Madurai, Cochi, Ooty, Mysore, Hampi and Goa to Mumbai. We always wanted to come back so this year we decided to pick up our journey and start in Mumbai and go up north to Delhi. We booked a flight to Mumbai and back from Delhi. We packed our Cycles as small as possible in Cardboard and flew with BA where you can take your cycles for free as long as you don't have more than 23 kg perperson. That is no problem because we try to travel as light as possible. We didn't take any tent because there are plenty of hotels or guesthouses everywhere and we didn't take a cooking stove or pans because there is food everywhere in India. We did take a lot of spare parts, Firts aid kit, sleeping bag, one set of normal clothes and three sets of cycling clothes. We carry everything in panniers
Our cycles are very basic, normal hardtail mountainbikes. They are aluminium and that can be a problem if anything bends or brakes because repairs will be very difficut. But steelframes are very difficult to get nowadays. They don't look expensive and that is very handy. The bikes are fitted with deore XT parts because these are the most dependable, I cycled about 25000km on mine and it is still in very good shape. Tires are very important and the best for long distance is marathon XR from Schwalbe. We only had one punture and considering all the glass and other trash on the roads this is a miracle!