You can have a whole day trip from Mumbai to alibaug and return in night...
if you are a beach lover then alibaug is the best place to visit as well as u can ride from Mumbai to alibaug which takes around 3-3 and half hours to reach
Best thing about Mumbai is the outskirts of Mumbai... there are lots of beautiful places and forts to visit. You just can run off the mundane city life and be alive n lost in western ghats' beauty. For bike trip it depends on which season are you planning. You can go
1) Old Mumbai-Pune highway in the monsoon end
3) Malshej ghat
4) Alibaug (but if you go off monsoon season you can go by ferry from gateway of India to mandwa) and then to Alibaug
n there's many more
If you are looking for some adventure and fun you must check out Bhandardara, dist. Ahmednagar, Maharashtra. It's an amazingly beautiful place. There are mountains all around. Bhandardara is situated in the midst of Sahyadri range. You must visit this place once at least. Check out The Land Of Wanderlust (TLOW) website..... https://thelandofwanderlust.com/ For Details please share your mail id or what's app message on +918450977725.