Suggest making a plan for the bike routes for a weekly trip and excise,
　

from Xindian to Danshui its totally around 70 km trip.

and we are on between at the middle of way.

once your are feel tired to ride, then you can take MRT back from each of points

we are at Ximen station exit 1 see MRT routes map

台北市台北西門町-斑馬屋短期出租公寓 (從西門捷運站走8分鐘)