Almost every cyclist living in the Asian part of İstanbul has experienced Bostancı-Kaynarca route at least once. The route is on the shore line and it has large lanes.
You can reach Bostancı from the European side by IDO sea buses or you can go to Kadıköy by ferries. Then, you can ride eight kilometers mostly on bicycle lane from Kadıköy to Bostancı. If you want to go a bit faster, you can choose coast road.
We can say that it is safer to use this road early in the mornings. But you should be careful about big trucks and minibuses on roads. If there is so much traffic, you should use the bicycle lane near coast road. It provides you a safe riding.
It is possible for you to see different facebook groups’ activities on this course. When you write “İstanbul Yol Bisikleti” or “Salı-Perşembe” on the search engine, you can see these groups and contact with them.
There are two starting points for Bostancı- Kaynarca route and it is thirty-five kilometers approximatelly. Whereas some groups prefer to start from first bus stop after Prince Islands pier, the others prefer to start from the traffic lights just in front of the Prince Islands pier. You can recognize this point when you see the yellow minibuses’ stop.
It is better to ride carefully because of the deformation on course asphalt. And also you need to be really careful about road links on corners and traffic lights.