I love cycling and I love India... but I am not sure if I would bring these too passions together.... partly the heat, partly the traffic. Maybe you can convince me I am wrong and suggest some areas of the country where a bike is the best way to travel!
I agree with your concern that there are many areas which has too much traffic but there are vast area where you can cycle in India like Himachal pradesh, Uttrakhand, Jammu & Kashmir, North-East India. These states have less traffic and natural beauty. I hope you will come and enjoy the cycling in India.