The one which I have tried a lot when I started:
From Marathalli go to Sarjapur j. Take a left on Sarjapur road. Go all the way upto railway crossing (just before decathlon) and take another left into the road which takes you to Karmelaram Railway stn. (slightly before railway crossing). This road is most pleasant ride in this part of city, full of missionary establishments and scenic view. It will take you to Gunjur village which is few kms from Varthur. Again take a left from Varthur village. Its another cool ride apart from some bumpy patches. Just keep going on it and finally you'll reach somewhere in Marathalli region. Don't know what that locality is called. A few turns here and there will take you to Ecospace.
Try it out on a weekend or weekday morning 6:00 kind of time.