Nandi hills are very close to Bangalore, hardly 75 km on hyd highway. It will be better day if you can go on weekends. Hill is not much big, but climbing to hill on bike especial is Dam good What I feel. Better time is winter and summer, if you are planning on summer then hills will be covered with full of clouds and clumsy will be awesome. You can enjoy till 11o clock and come back.
I wanna tell you some safty things if you are planning here. Please go with 2 helmets and dl. All your bike or car docs because there will be a police checkup will be there at airport toll gate.
Guys please dont booz over there, as many of you heard about 2 girls what happened to them. Just they lost lifes. Please keep in mind of these things, you are in safe hands
Enjoy your trip.!