Bike Routes: 

Scarborough : One of the prettiest and easiest trails in the area is known as the Eastern Trail. It's great for adults and suitable for children on two wheelers without traing wheels. It's a mixed use trail (no cars) and is popular with walkers and runners. It wide enough for all and has parking on Pine Point road and just off Black Point Road.  It's an old rail bed and part of the Great Eastern Trail. It will take you right through the Scarborough marsh! You may see great blue herons, snowy egrets, red winged black birds and fish hawks. You may also see some our our kayak rental customers in our bright yellow kayaks enjoying the marsh close up. Here's a link to a map.   http://www.bkll.com/maps/bike-path/Eastern-Trail-Scarborough-to-Pine-Point-Rd

Old Orchard Beach: Here's a map that shows a long ride along the beach with an opportunity to add a loop or two for a longer ride. Pick any section of the section along the beach. There are lots of places to stop for refreshments and to access the beach for a swim. There are almost too many things to mention to do an this route. Our favorites are the village of Ocean Park and the pier on Old Orchard. The two are only a few miles apart, and couldn't be more diferent. Stop by and you'll see. This route is on low speed limit roads, so there are cars and trucks. Motorists are generally very aware of bikes, and Maine has a 3 foot rule for cars passing bikes.
http://www.bikely.com/maps/bike-path/Old-Orchard-Beach-Scarborough-Saco-Route-1