We rode the trail during the first week of October. The colors were spectacular, especially after about mile 6 in the bog areas. There is wonderful variety along the trail as one starts out in Wolfeboro, goes on causeways through Lake Wentworth, through Wentworth State Park and then on through woods and bogs.

The trail itself requires riders to pay lots of attention to safety. Much of the trail is situated between the two metal rails of the old train track--so it is quite narrow. This is rideable, though. As others have mentioned, there are many points where you switch onto a hard packed limestone trail next to the tracks. It's turning off the rails onto the limestone trails where one must slow down and do a sharp turn. We encountered 2 people who had fallen at these turn off points and one accomplished rider in our group fell as well. It's just easy to catch your tires in the crack between the rails if you don't do almost a 90 degree turn.

All that said, it's a rustic and beautiful ride and I'd highly recommend it for hybrid or gravel bikes. And, there's amazing ice cream at the iconic Bailey's Bubble when you get back to Wolfeboro!

My wife and rode 10 miles through Biddeford to the Scarborough Marsh and back. We felt the town part was pretty well marked but you need to pay attention as you transition from sidewalks, to streets, to crosswalks, etc. Once you navigate that part of the trail it lines out straight north to the marsh. This section is a very pleasant and wide part with several road crossings. The roads aren't especially busy and gives access to businesses and a change in route if desired. Even if the town section isn't the most desirable it is nice to be able to jump on a trail right in town. Well worth the effort to ride this section of trail.

My wife and I rode this trail for a few miles out of Wolfeboro. The builders of this trail did a wonderful job navigating through town. As you leave town you get lovely views of the lake especially when riding on the causeway (I will call it). We found no trouble navigating over the rails. There seemed to be plenty of room to meet other bikers and walkers. This whole area is really fantastic.

Beautiful trail! Met a fellow bicycle rider from New Jersey who helped encourage me through the rain!

We began the trail at Miller's Park also known as the Papermill Trail. Nice and easy, great asphalt path

I’ve ridden Kennebunk to Biddeford a couple of times in the past week (late Sept), the trail is well maintained and marked. The few vehicle crossings have cross walks and signage for drivers. This is a beautiful trail that I would highly recommend, looking forward to riding all the way to South Portland!

We parked at the Windham PO and rode along the tracks until we got to Rt-35, did a bit of exploring at the Otter Ponds, then came back. It was a sweet ride: no bugs, great Sharon weather—we were a little disappointed that we couldn’t go directly to the Lake, but I see now we could have gone left and gotten to the water…. Next time. We stopped at the Orchard Ridge Farm and had a delicious cider donut at the intersection with Sebago Lakes Rd. ~10

This trail is for mountain or hybrid bikes, definitely not road bikes.
Agree with others in that there are more pedestrians near Wolfboro but the trail gets much less traveled the farther away you go.
Also agree that the trails are narrow but this is not an issue because the visibility is so good. Most of the time, you can see people coming from other direction literally hundreds a feet ahead of time. I did get stuck behind a few slower bikers but was able to pass at one of the railroad track crossovers.
As the railroad track crossovers, you just have to slow down and ensure your front tire is crossing at a 90 degree angle. I didn’t have any issues at all but just be mindful, slow down and steer the front tire to cross over perpendicular to the rail.
So, definitely some things to consider and manage but well worth it in my opinion.

As many others have noted, this trail is not safe for bikes, especially road and hybrid models. We read the reviews warning us in advance and rode wide tire bikes. Despite rubber mats at many of the points where you transition from between the rails to beside them or vice versa, it's still possible to get a tire caught in the small gap between the mat and the rails and take a fall. Be forewarned to SLOW DOWN or walk your bike across these numerous transition points. Also, the sections of the trail that run between the rails are too narrow for a bike going one way to safely pass a walker going the other. When it's two bikes going in opposite directions, one has to come to a stop to pass safely. The sections of the trail outside the rails aren't much wider and the railroad ties extend about six inches beyond the rails, further squeezing the available space. My conclusion is that there must be hundreds of single bike, bike-bike and bike-pedestrian accidents annually.

The trail is otherwise quite nice. Its almost totally flat and there's plenty of shade.