What about the OCA route, East of Mosholu Parkway? NYCC OCA route goes this way:
https://ridewithgps.com/routes/25327095 Then there is a short stretch on Yonkers Avenue, and one can walk up the stairs back to SCT.
Is cycling allowed there? Google maps and Openstreetmaps mark it as a bike trail. If it is in a bad condition it may be a bad idea to bike there and erode the trail even more -- anyway, the main trail is getting paved, so we can wait for it to happen.