There are lots of ups and downs along this fantastic paved bike path that runs along Route 93 through Franconia Notch. Your best option is to spot a car at the Basin or at the Flume if you want to ride the entire bike route. Starting at Echo Lake right next to Cannon Mountain gives you plenty of parking and the majority of the riding is downhill.

Biking by Echo Lake and Cannon Mountain Ski Area
With younger cyclists, or ones new to biking this is the best way to go, we tried both ways and going from South to North takes a lot more effort. The trail winds under Route 93 a couple times, and along the base of Cannon Cliff. Most of the time it wanders alongside the beginings of the Pemigewasset River.
About half way through there is Lafayette Campground where you can stop and grab some snacks at the camp store, or just ride on by. Towards the end of the ride make sure to stop by The Basin to cool off or check out the “potholes” carved into the granite. Not far from The Basin, a few miles you’ll get to The Flume parking lot and the end of the ride.