Try any of the following rides:
Rajmachi - 17kms of Off road ride near Khandaka
Yeoor Hills near Thane - 1 km climb
Kharghar hills near CBD Belapur, New Mumbai
Palm Beach Road
Panvel to Kholpoli 35 kms
1) Thane Ghodbunder Road. Good stretch for climbs.
2) Eastern Express Highway between Thane and Deonar.